Mass Spectrometry on WIkipedia

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	[[ru:Электронная ионизация]]		[[ru:Электронная ионизация]]

Kkmurray: case

Thu, 19 Nov 2009 14:18:44 -0800

case

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	[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]		[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]

-	'''Mass Spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:	+	'''Mass spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:
	# a sample is loaded onto the MS instrument, and undergoes vaporization.		# a sample is loaded onto the MS instrument, and undergoes vaporization.
	# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)		# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)

Pingveno at 21:15, 19 November 2009

Thu, 19 Nov 2009 13:15:25 -0800

← Previous revision		Revision as of 21:15, 19 November 2009
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	[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]		[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]

-	'''Mass Spatromery''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:	+	'''Mass Spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:
	# a sample is loaded onto the MS instrument, and undergoes vaporization.		# a sample is loaded onto the MS instrument, and undergoes vaporization.
	# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)		# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)

Trivelt: Reverted edits by 158.165.239.159 (talk) to last version by 158.165.239.209

Thu, 19 Nov 2009 13:14:14 -0800

Reverted edits by 158.165.239.159 (talk) to last version by 158.165.239.209

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158.165.239.159: ←Replaced content with 'hello do you know about the bird!'

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158.165.239.209 at 21:12, 19 November 2009

Thu, 19 Nov 2009 13:12:10 -0800

← Previous revision		Revision as of 21:12, 19 November 2009
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	[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]		[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]

-	'''Mass spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:	+	'''Mass Spatromery''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:
	# a sample is loaded onto the MS instrument, and undergoes vaporization.		# a sample is loaded onto the MS instrument, and undergoes vaporization.
	# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)		# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)

A8UDI: Reverted edits by 158.165.239.159 (talk) to last version by Kkmurray

Thu, 19 Nov 2009 13:10:01 -0800

Reverted edits by 158.165.239.159 (talk) to last version by Kkmurray

← Previous revision		Revision as of 21:10, 19 November 2009
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	[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]		[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]

-	''hdbcdbcgdsvcg vscg vzcxv HXGV hmGSVC mbvx mds nsvcgsdvchgdmsv255/ejms.878 }}</ref> A ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = Thomson \| first = J.J. \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an [[oscilloscope]].<ref name='Siri_1947'> {{cite journal\|title=Mass spectroscope for analysis in the low-mass range\|journal=Review of Scientific Instruments\|month= August \| year= 1947\|first=William\|last=Siri\|coauthors=\|volume=18\|issue=8\|pages=540–545\|doi= 10.1063/1.1740998\|url=http://link.aip.org/link/?RSINAK/18/540/1\|format=\|accessdate=2007-12-06 }}</ref> The use of the term ''mass spectroscopy'' is now discouraged due to the possibility of confusion with light [[spectroscopy]].<ref name="isbn0-9660813-2-3"/><ref name="isbn0-9660813-2-3"/><ref name='Price 1991'> {{cite journal\|title=Standard definitions of terms relating to mass spectrometry. A report from the Committee on Measurements and Standards of the American Society for Mass Spectrometry\|journal=Journal of the American Society for Mass Spectrometry\|year=1991\|first=Phil\|last=Price\|coauthors=\|volume=2\|issue=4\|pages=336–348\|doi=10.1016/1044-0305(91)80025-3\|format=\|accessdate=2007-12-06 }}</ref> Mass spectrometry is often abbreviated as ''mass-spec'' or simply as ''MS''.<ref name="isbn0-9660813-2-3"/> Thomson has also noted that a ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = J.J. \| first = Thomson \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year =c 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> The suffix [[-scope]] here denotes the direct viewing of the [[spectra]] (range) of masses.	+	'''Mass spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:
		+	# a sample is loaded onto the MS instrument, and undergoes vaporization.
		+	# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)
		+	# The positive ions are then accelerated by a magnetic field
		+	# computation of the [[mass-to-charge ratio]] of the particles based on the details of motion of the ions as they transit through [[Electromagnetism\|electromagnetic]] fields, and
		+	# detection of the ions, which in step 4 were sorted according to m/z.
		+
		+	MS instruments consist of three modules: an ''[[ion source]]'', which can convert gas phase sample molecules into ions (or, in the case of electrospray ionization, move ions that exist in solution into the gas phase); a ''mass analyzer'', which sorts the ions by their masses by applying electromagnetic fields; and a ''detector'', which measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present. The technique has both [[qualitative]] and [[Quantitative analysis (chemistry)\|quantitative]] uses. These include identifying unknown compounds, determining the [[isotope\|isotopic]] composition of elements in a molecule, and determining the [[structure]] of a compound by observing its fragmentation. Other uses include quantifying the amount of a compound in a sample or studying the fundamentals of [[gas phase ion chemistry]] (the chemistry of ions and neutrals in a vacuum). MS is now in very common use in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds.
		+
		+	==Etymology==
		+	The word ''spectrograph'' has been used since 1884 as an "''International Scientific Vocabulary''".<ref>"[http://dev.m-w.com/dictionary/spectrograph Definition of spectrograph]." Merriam Webster. Accessed 13 June 2008.</ref><ref>{{cite journal \| title = William Aston - the man behind the mass spectrograph \| author = KM Downard \| journal = European Journal of Mass Spectrometry \| volume = 13 \| issue = 3 \| pages = 177–190 \| year = 2007 \| url = \| doi = 10.1255/ejms.878 }}</ref>
		+	The [[Root (linguistics)\|linguistic roots]] are a combination and removal of [[bound morpheme]]s and [[free morpheme]]s which relate to the terms '''''spectr'''-um'' and ''phot-'''ograph'''-ic plate''.<ref>Harper, Douglas. "[http://www.etymonline.com/index.php?search=spectrum&searchmode=none Spectrum]." [[Online Etymology Dictionary]]. Nov. 2001. Accessed 07-12-2007.<small> '''Note''': This part of the article only makes descriptive claims about the information found in the primary source, the accuracy and applicability of which is easily verifiable by any reasonable, educated person without specialist knowledge. (See [[WP:PSTS]])</small></ref> Early ''spectrometry'' devices that measured the mass-to-charge ratio of ions were called ''[[spectrograph\|mass spectrographs]]'' which consisted of instruments that recorded a [[spectrum]] of mass values on a [[photographic plate]].<ref name='a804629h'> {{cite journal\|title=Francis Aston and the mass spectrograph\|journal=[[Dalton Transactions]]\|year=1998\|first=Gordon\|last=Squires\|coauthors=\|volume=\|issue=\|pages=3893–3900\|doi= 10.1039/a804629h\|url=http://www.rsc.org/publishing/journals/DT/article.asp?doi=a804629h\|format=\|accessdate=2007-12-06 }}</ref><ref> {{cite journal \| title = Francis William Aston - the man behind the mass spectrograph \| author = KM Downard \| journal = European Journal of Mass Spectrometry \| volume = 13 \| issue = 3 \| pages = 177–190 \| year = 2007 \| url = \| doi = 10.1255/ejms.878 }}</ref> A ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = Thomson \| first = J.J. \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an [[oscilloscope]].<ref name='Siri_1947'> {{cite journal\|title=Mass spectroscope for analysis in the low-mass range\|journal=Review of Scientific Instruments\|month= August \| year= 1947\|first=William\|last=Siri\|coauthors=\|volume=18\|issue=8\|pages=540–545\|doi= 10.1063/1.1740998\|url=http://link.aip.org/link/?RSINAK/18/540/1\|format=\|accessdate=2007-12-06 }}</ref> The use of the term ''mass spectroscopy'' is now discouraged due to the possibility of confusion with light [[spectroscopy]].<ref name="isbn0-9660813-2-3"/><ref name="isbn0-9660813-2-3"/><ref name='Price 1991'> {{cite journal\|title=Standard definitions of terms relating to mass spectrometry. A report from the Committee on Measurements and Standards of the American Society for Mass Spectrometry\|journal=Journal of the American Society for Mass Spectrometry\|year=1991\|first=Phil\|last=Price\|coauthors=\|volume=2\|issue=4\|pages=336–348\|doi=10.1016/1044-0305(91)80025-3\|format=\|accessdate=2007-12-06 }}</ref> Mass spectrometry is often abbreviated as ''mass-spec'' or simply as ''MS''.<ref name="isbn0-9660813-2-3"/> Thomson has also noted that a ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = J.J. \| first = Thomson \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> The suffix [[-scope]] here denotes the direct viewing of the [[spectra]] (range) of masses.

	==History==		==History==

158.165.239.159 at 21:09, 19 November 2009

Thu, 19 Nov 2009 13:09:43 -0800

← Previous revision		Revision as of 21:09, 19 November 2009
Line 1:		Line 1:
	[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]		[[Image:Ms block schematic.gif\|right\|thumb\|275px\|Main steps of measuring with a mass spectrometer]]

-	'''Mass spectrometry''' (MS) is an analytical technique for the determination of the elemental composition of a sample or [[molecule]]. It is also used for elucidating the chemical structures of molecules, such as [[peptide]]s and other [[chemical compound]]s. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their [[mass-to-charge ratio]]s.<ref name="isbn0-9660813-2-3">{{cite book \|author=Sparkman, O. David \|title=Mass spectrometry desk reference \|publisher=Global View Pub \|location=Pittsburgh \|year=2000 \|pages= \|isbn=0-9660813-2-3 \|oclc= \|doi=}}</ref> In a typical MS procedure:	+	''hdbcdbcgdsvcg vscg vzcxv HXGV hmGSVC mbvx mds nsvcgsdvchgdmsv255/ejms.878 }}</ref> A ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = Thomson \| first = J.J. \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an [[oscilloscope]].<ref name='Siri_1947'> {{cite journal\|title=Mass spectroscope for analysis in the low-mass range\|journal=Review of Scientific Instruments\|month= August \| year= 1947\|first=William\|last=Siri\|coauthors=\|volume=18\|issue=8\|pages=540–545\|doi= 10.1063/1.1740998\|url=http://link.aip.org/link/?RSINAK/18/540/1\|format=\|accessdate=2007-12-06 }}</ref> The use of the term ''mass spectroscopy'' is now discouraged due to the possibility of confusion with light [[spectroscopy]].<ref name="isbn0-9660813-2-3"/><ref name="isbn0-9660813-2-3"/><ref name='Price 1991'> {{cite journal\|title=Standard definitions of terms relating to mass spectrometry. A report from the Committee on Measurements and Standards of the American Society for Mass Spectrometry\|journal=Journal of the American Society for Mass Spectrometry\|year=1991\|first=Phil\|last=Price\|coauthors=\|volume=2\|issue=4\|pages=336–348\|doi=10.1016/1044-0305(91)80025-3\|format=\|accessdate=2007-12-06 }}</ref> Mass spectrometry is often abbreviated as ''mass-spec'' or simply as ''MS''.<ref name="isbn0-9660813-2-3"/> Thomson has also noted that a ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = J.J. \| first = Thomson \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year =c 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> The suffix [[-scope]] here denotes the direct viewing of the [[spectra]] (range) of masses.
-	# a sample is loaded onto the MS instrument, and undergoes vaporization.
-	# the components of the sample are ionized by one of a variety of methods (e.g., by impacting them with an [[electron]] beam), which results in the formation of positively charged particles ([[ion]]s)
-	# The positive ions are then accelerated by a magnetic field
-	# computation of the [[mass-to-charge ratio]] of the particles based on the details of motion of the ions as they transit through [[Electromagnetism\|electromagnetic]] fields, and
-	# detection of the ions, which in step 4 were sorted according to m/z.
-
-	MS instruments consist of three modules: an ''[[ion source]]'', which can convert gas phase sample molecules into ions (or, in the case of electrospray ionization, move ions that exist in solution into the gas phase); a ''mass analyzer'', which sorts the ions by their masses by applying electromagnetic fields; and a ''detector'', which measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present. The technique has both [[qualitative]] and [[Quantitative analysis (chemistry)\|quantitative]] uses. These include identifying unknown compounds, determining the [[isotope\|isotopic]] composition of elements in a molecule, and determining the [[structure]] of a compound by observing its fragmentation. Other uses include quantifying the amount of a compound in a sample or studying the fundamentals of [[gas phase ion chemistry]] (the chemistry of ions and neutrals in a vacuum). MS is now in very common use in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds.
-
-	==Etymology==
-	The word ''spectrograph'' has been used since 1884 as an "''International Scientific Vocabulary''".<ref>"[http://dev.m-w.com/dictionary/spectrograph Definition of spectrograph]." Merriam Webster. Accessed 13 June 2008.</ref><ref>{{cite journal \| title = William Aston - the man behind the mass spectrograph \| author = KM Downard \| journal = European Journal of Mass Spectrometry \| volume = 13 \| issue = 3 \| pages = 177–190 \| year = 2007 \| url = \| doi = 10.1255/ejms.878 }}</ref>
-	The [[Root (linguistics)\|linguistic roots]] are a combination and removal of [[bound morpheme]]s and [[free morpheme]]s which relate to the terms '''''spectr'''-um'' and ''phot-'''ograph'''-ic plate''.<ref>Harper, Douglas. "[http://www.etymonline.com/index.php?search=spectrum&searchmode=none Spectrum]." [[Online Etymology Dictionary]]. Nov. 2001. Accessed 07-12-2007.<small> '''Note''': This part of the article only makes descriptive claims about the information found in the primary source, the accuracy and applicability of which is easily verifiable by any reasonable, educated person without specialist knowledge. (See [[WP:PSTS]])</small></ref> Early ''spectrometry'' devices that measured the mass-to-charge ratio of ions were called ''[[spectrograph\|mass spectrographs]]'' which consisted of instruments that recorded a [[spectrum]] of mass values on a [[photographic plate]].<ref name='a804629h'> {{cite journal\|title=Francis Aston and the mass spectrograph\|journal=[[Dalton Transactions]]\|year=1998\|first=Gordon\|last=Squires\|coauthors=\|volume=\|issue=\|pages=3893–3900\|doi= 10.1039/a804629h\|url=http://www.rsc.org/publishing/journals/DT/article.asp?doi=a804629h\|format=\|accessdate=2007-12-06 }}</ref><ref> {{cite journal \| title = Francis William Aston - the man behind the mass spectrograph \| author = KM Downard \| journal = European Journal of Mass Spectrometry \| volume = 13 \| issue = 3 \| pages = 177–190 \| year = 2007 \| url = \| doi = 10.1255/ejms.878 }}</ref> A ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = Thomson \| first = J.J. \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> A mass spectroscope configuration was used in early instruments when it was desired that the effects of adjustments be quickly observed. Once the instrument was properly adjusted, a photographic plate was inserted and exposed. The term mass spectroscope continued to be used even though the direct illumination of a phosphor screen was replaced by indirect measurements with an [[oscilloscope]].<ref name='Siri_1947'> {{cite journal\|title=Mass spectroscope for analysis in the low-mass range\|journal=Review of Scientific Instruments\|month= August \| year= 1947\|first=William\|last=Siri\|coauthors=\|volume=18\|issue=8\|pages=540–545\|doi= 10.1063/1.1740998\|url=http://link.aip.org/link/?RSINAK/18/540/1\|format=\|accessdate=2007-12-06 }}</ref> The use of the term ''mass spectroscopy'' is now discouraged due to the possibility of confusion with light [[spectroscopy]].<ref name="isbn0-9660813-2-3"/><ref name="isbn0-9660813-2-3"/><ref name='Price 1991'> {{cite journal\|title=Standard definitions of terms relating to mass spectrometry. A report from the Committee on Measurements and Standards of the American Society for Mass Spectrometry\|journal=Journal of the American Society for Mass Spectrometry\|year=1991\|first=Phil\|last=Price\|coauthors=\|volume=2\|issue=4\|pages=336–348\|doi=10.1016/1044-0305(91)80025-3\|format=\|accessdate=2007-12-06 }}</ref> Mass spectrometry is often abbreviated as ''mass-spec'' or simply as ''MS''.<ref name="isbn0-9660813-2-3"/> Thomson has also noted that a ''mass spectroscope'' is similar to a ''mass spectrograph'' except that the beam of ions is directed onto a [[phosphor]] screen.<ref>{{cite book \| last = J.J. \| first = Thomson \| authorlink = J. J. Thomson \| coauthors = \| title = Rays Of Positive Electricity and Their Application to Chemical Analysis \| publisher = Longman's Green and Company \| year = 1913 \| location = London \| pages = \| url = http://www.archive.org/details/RaysOfPositiveElectricity \| doi = \| id = \| isbn = }}</ref> The suffix [[-scope]] here denotes the direct viewing of the [[spectra]] (range) of masses.

	==History==		==History==

Vsmith: Reverted edits by 24.149.253.130 (talk) to last version by Rich Farmbrough

Thu, 19 Nov 2009 11:40:03 -0800

Reverted edits by 24.149.253.130 (talk) to last version by Rich Farmbrough

← Previous revision		Revision as of 19:40, 19 November 2009
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	==Classical ionization==		==Classical ionization==

-	Applying only [[classical physics]] and the [[Bohr model]] of the atom makes both atomic and molecular ionization entirely [[Scientific determinism\|deterministic]]; that is, every problem will always have a definite and computable answer. According to classical physics, it is absolutely necessary that the energy of the electron exceeds the energy difference of the potential barrier it is trying to pass. In concept, this idea should make sense: The same way a person cannot jump over a one-meter wall without jumping at least one meter off the ground, an electron cannot get over a 13.6-[[Electronvolt\|eV]] potential barrier without at least 13.6 eV of energy. Frazer pooded.	+	Applying only [[classical physics]] and the [[Bohr model]] of the atom makes both atomic and molecular ionization entirely [[Scientific determinism\|deterministic]]; that is, every problem will always have a definite and computable answer. According to classical physics, it is absolutely necessary that the energy of the electron exceeds the energy difference of the potential barrier it is trying to pass. In concept, this idea should make sense: The same way a person cannot jump over a one-meter wall without jumping at least one meter off the ground, an electron cannot get over a 13.6-[[Electronvolt\|eV]] potential barrier without at least 13.6 eV of energy.

	===Applying to positive ionization===		===Applying to positive ionization===

-	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state. But the physical stuff is all false.	+	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.

	===Applying to negative ionization===		===Applying to negative ionization===

24.149.253.130: /* Classical ionization */

Thu, 19 Nov 2009 11:18:05 -0800

Classical ionization

← Previous revision		Revision as of 19:18, 19 November 2009
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	==Classical ionization==		==Classical ionization==

-	Applying only [[classical physics]] and the [[Bohr model]] of the atom makes both atomic and molecular ionization entirely [[Scientific determinism\|deterministic]]; that is, every problem will always have a definite and computable answer. According to classical physics, it is absolutely necessary that the energy of the electron exceeds the energy difference of the potential barrier it is trying to pass. In concept, this idea should make sense: The same way a person cannot jump over a one-meter wall without jumping at least one meter off the ground, an electron cannot get over a 13.6-[[Electronvolt\|eV]] potential barrier without at least 13.6 eV of energy.	+	Applying only [[classical physics]] and the [[Bohr model]] of the atom makes both atomic and molecular ionization entirely [[Scientific determinism\|deterministic]]; that is, every problem will always have a definite and computable answer. According to classical physics, it is absolutely necessary that the energy of the electron exceeds the energy difference of the potential barrier it is trying to pass. In concept, this idea should make sense: The same way a person cannot jump over a one-meter wall without jumping at least one meter off the ground, an electron cannot get over a 13.6-[[Electronvolt\|eV]] potential barrier without at least 13.6 eV of energy. Frazer pooded.

	===Applying to positive ionization===		===Applying to positive ionization===

24.149.253.130: /* Classical ionization */

Thu, 19 Nov 2009 11:16:55 -0800

Classical ionization

← Previous revision		Revision as of 19:16, 19 November 2009
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	===Applying to positive ionization===		===Applying to positive ionization===

-	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.	+	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state. But the physical stuff is all false.

	===Applying to negative ionization===		===Applying to negative ionization===

Rich Farmbrough: /* References */Delink dates (WP:MOSUNLINKDATES) using AWB

Wed, 18 Nov 2009 01:48:29 -0800

References: Delink dates (WP:MOSUNLINKDATES) using AWB

← Previous revision		Revision as of 09:48, 18 November 2009
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	==References==		==References==
	{{No footnotes\|date=April 2009}}		{{No footnotes\|date=April 2009}}
-	* Sequential ionization of C<sub>60</sub> with femtosecond laser pulses. The Journal of Chemical Physics -- [[January 22]] [[2001]] -- Volume 114, Issue 4, pp. 1716–1719.	+	* Sequential ionization of C<sub>60</sub> with femtosecond laser pulses. The Journal of Chemical Physics -- January 22, 2001 -- Volume 114, Issue 4, pp. 1716–1719.
	* Can harmonic generation cause non-sequential ionization? J. Phys. B: At. Mol. Opt. Phys. 31 No 19 (14 October 1998) L841-L848.		* Can harmonic generation cause non-sequential ionization? J. Phys. B: At. Mol. Opt. Phys. 31 No 19 (14 October 1998) L841-L848.
	* Probing atomic ionization mechanisms in intense laser fields by calculating geometry and diffraction independent ionization probabilities. J Wood, E M L English, S L Stebbings, W A Bryan, W R *Newell, J McKenna, M Suresh, B Srigengan, I D Williams, I C E Turcu, J M Smith, K G Ertel, E J Divall, C J Hooker, A J Langley. {{PDFlink\|http://www.clf.rl.ac.uk/Reports/2004-2005/pdf/26.pdf\|217 [[Kibibyte\|KiB]]<!-- application/pdf, 223112 bytes -->}}		* Probing atomic ionization mechanisms in intense laser fields by calculating geometry and diffraction independent ionization probabilities. J Wood, E M L English, S L Stebbings, W A Bryan, W R *Newell, J McKenna, M Suresh, B Srigengan, I D Williams, I C E Turcu, J M Smith, K G Ertel, E J Divall, C J Hooker, A J Langley. {{PDFlink\|http://www.clf.rl.ac.uk/Reports/2004-2005/pdf/26.pdf\|217 [[Kibibyte\|KiB]]<!-- application/pdf, 223112 bytes -->}}

Kkmurray: Reverted 2 edits by 122.168.8.67 identified as vandalism to last revision by Siegele. (TW)

Mon, 16 Nov 2009 12:38:12 -0800

Reverted 2 edits by 122.168.8.67 identified as vandalism to last revision by Siegele. (TW)

← Previous revision		Revision as of 20:38, 16 November 2009
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	[[File:Early Mass Spectrometer (replica).jpg\|thumb\|300px\|Replica of an early mass spectrometer]]		[[File:Early Mass Spectrometer (replica).jpg\|thumb\|300px\|Replica of an early mass spectrometer]]
	[[Image:Francis William Aston.jpg\|150 px\|thumb\|left\|Francis William Aston won the 1922 Nobel Prize in Chemistry for his work in mass spectrometry]]		[[Image:Francis William Aston.jpg\|150 px\|thumb\|left\|Francis William Aston won the 1922 Nobel Prize in Chemistry for his work in mass spectrometry]]
-	In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric a	+	In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (''Q/m''). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist [[J.J. Thomson]] later improved on the work of Wien by reducing the pressure to create a mass spectrograph.
		+
		+	Some of the modern techniques of mass spectrometry were devised by [[Arthur Jeffrey Dempster]] and [[F.W. Aston]] in 1918 and 1919 respectively. In 1989, half of the [[Nobel Prize in Physics]] was awarded to [[Hans Dehmelt]] and [[Wolfgang Paul]] for the development of the ion trap technique in the 1950s and 1960s. In 2002, the [[Nobel Prize in Chemistry]] was awarded to [[John Bennett Fenn]] for the development of [[electrospray ionization]] (ESI) and [[Koichi Tanaka]] for the development of [[soft laser desorption]] (SLD) in 1987. However earlier, [[matrix-assisted laser desorption/ionization]] (MALDI), was developed by [[Franz Hillenkamp]] and [[Michael Karas]]; this technique has been widely used for protein analysis.<ref>Measuring Mass: From Positive Rays to Proteins by Michael A. Grayson (Editor) (ISBN 0-941901-31-9)</ref>
		+
		+	The first application of mass spectrometry to the analysis of amino acids and peptides was reported in 1958.<ref>''Carl-Ove Anderson'', Acta. Chem. Scand. '''1958''', 12, 1353</ref> Carl-Ove Anderson highlighted the main fragment ions observed in the ionization of methyl esters.<ref>''Mass Spec Anniversary'', [[Chemical & Engineering News]], '''87''', 6 (9 Feb. 2009), p. 4</ref>

	==Simplified example==		==Simplified example==

122.168.8.67: /* History */

Mon, 16 Nov 2009 08:25:03 -0800

History

← Previous revision		Revision as of 16:25, 16 November 2009
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	[[File:Early Mass Spectrometer (replica).jpg\|thumb\|300px\|Replica of an early mass spectrometer]]		[[File:Early Mass Spectrometer (replica).jpg\|thumb\|300px\|Replica of an early mass spectrometer]]
	[[Image:Francis William Aston.jpg\|150 px\|thumb\|left\|Francis William Aston won the 1922 Nobel Prize in Chemistry for his work in mass spectrometry]]		[[Image:Francis William Aston.jpg\|150 px\|thumb\|left\|Francis William Aston won the 1922 Nobel Prize in Chemistry for his work in mass spectrometry]]
-	In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (''Q/m''). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist [[J.J. Thomson]] later improved on the work of Wien by reducing the pressure to create a mass spectrograph.	+	In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric a
-
-	Some of the modern techniques of mass spectrometry were devised by [[Arthur Jeffrey Dempster]] and [[F.W. Aston]] in 1918 and 1919 respectively. In 1989, half of the [[Nobel Prize in Physics]] was awarded to [[Hans Dehmelt]] and [[Wolfgang Paul]] for the development of the ion trap technique in

	==Simplified example==		==Simplified example==

122.168.8.67: /* History */

Mon, 16 Nov 2009 08:24:06 -0800

History

← Previous revision		Revision as of 16:24, 16 November 2009
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	In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (''Q/m''). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist [[J.J. Thomson]] later improved on the work of Wien by reducing the pressure to create a mass spectrograph.		In 1886, [[Eugen Goldstein]] observed rays in [[gas discharge]]s under low pressure that traveled away from the anode and through channels in a perforated [[cathode]], opposite to the direction of negatively charged [[cathode rays]] (which travel from cathode to anode). Goldstein called these positively charged [[anode rays]] "Kanalstrahlen"; the standard translation of this term into English is "[[canal rays]]". [[Wilhelm Wien]] found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (''Q/m''). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist [[J.J. Thomson]] later improved on the work of Wien by reducing the pressure to create a mass spectrograph.

-	Some of the modern techniques of mass spectrometry were devised by [[Arthur Jeffrey Dempster]] and [[F.W. Aston]] in 1918 and 1919 respectively. In 1989, half of the [[Nobel Prize in Physics]] was awarded to [[Hans Dehmelt]] and [[Wolfgang Paul]] for the development of the ion trap technique in the 1950s and 1960s. In 2002, the [[Nobel Prize in Chemistry]] was awarded to [[John Bennett Fenn]] for the development of [[electrospray ionization]] (ESI) and [[Koichi Tanaka]] for the development of [[soft laser desorption]] (SLD) in 1987. However earlier, [[matrix-assisted laser desorption/ionization]] (MALDI), was developed by [[Franz Hillenkamp]] and [[Michael Karas]]; this technique has been widely used for protein analysis.<ref>Measuring Mass: From Positive Rays to Proteins by Michael A. Grayson (Editor) (ISBN 0-941901-31-9)</ref>	+	Some of the modern techniques of mass spectrometry were devised by [[Arthur Jeffrey Dempster]] and [[F.W. Aston]] in 1918 and 1919 respectively. In 1989, half of the [[Nobel Prize in Physics]] was awarded to [[Hans Dehmelt]] and [[Wolfgang Paul]] for the development of the ion trap technique in
-
-	The first application of mass spectrometry to the analysis of amino acids and peptides was reported in 1958.<ref>''Carl-Ove Anderson'', Acta. Chem. Scand. '''1958''', 12, 1353</ref> Carl-Ove Anderson highlighted the main fragment ions observed in the ionization of methyl esters.<ref>''Mass Spec Anniversary'', [[Chemical & Engineering News]], '''87''', 6 (9 Feb. 2009), p. 4</ref>

	==Simplified example==		==Simplified example==

165.91.89.34 at 18:06, 12 November 2009

Thu, 12 Nov 2009 10:06:37 -0800

← Previous revision		Revision as of 18:06, 12 November 2009
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	[[Image:Ionization energies.png\|right\|thumb\|400px\|Ionization energies of neutral elements.]]		[[Image:Ionization energies.png\|right\|thumb\|400px\|Ionization energies of neutral elements.]]
-	'''Ionization''' is the [[physics\|physical]] the whole world blows up and engulfs the sun burning th planet uoprocess of converting an [[atom]] or [[molecule]] into an [[ion]] by adding or removing charged particles such as [[electron]]s or other ions. This is often confused with [[dissociation (chemistry)]].	+	'''Ionization''' is the [[physics\|physical]] process of converting an [[atom]] or [[molecule]] into an [[ion]] by adding or removing charged particles such as [[electron]]s or other ions. This is often confused with [[dissociation (chemistry)]].

	The process works slightly differently depending on whether an ion with a positive or a negative [[electric charge]] is being produced. A positively-charged ion is produced when an electron bonded to an atom (or molecule) absorbs enough energy to escape from the [[electric potential]] barrier that originally confined it, thus breaking the bond and freeing it to move. The amount of energy required is called the [[ionization potential]]. A negatively-charged ion is produced when a free electron collides with an atom and is subsequently caught inside the electric potential barrier, releasing any excess energy.		The process works slightly differently depending on whether an ion with a positive or a negative [[electric charge]] is being produced. A positively-charged ion is produced when an electron bonded to an atom (or molecule) absorbs enough energy to escape from the [[electric potential]] barrier that originally confined it, thus breaking the bond and freeing it to move. The amount of energy required is called the [[ionization potential]]. A negatively-charged ion is produced when a free electron collides with an atom and is subsequently caught inside the electric potential barrier, releasing any excess energy.

209.232.116.102 at 17:39, 12 November 2009

Thu, 12 Nov 2009 09:39:49 -0800

← Previous revision		Revision as of 17:39, 12 November 2009
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	[[Image:Ionization energies.png\|right\|thumb\|400px\|Ionization energies of neutral elements.]]		[[Image:Ionization energies.png\|right\|thumb\|400px\|Ionization energies of neutral elements.]]
-	'''Ionization''' is the [[physics\|physical]] process of converting an [[atom]] or [[molecule]] into an [[ion]] by adding or removing charged particles such as [[electron]]s or other ions. This is often confused with [[dissociation (chemistry)]].	+	'''Ionization''' is the [[physics\|physical]] the whole world blows up and engulfs the sun burning th planet uoprocess of converting an [[atom]] or [[molecule]] into an [[ion]] by adding or removing charged particles such as [[electron]]s or other ions. This is often confused with [[dissociation (chemistry)]].

	The process works slightly differently depending on whether an ion with a positive or a negative [[electric charge]] is being produced. A positively-charged ion is produced when an electron bonded to an atom (or molecule) absorbs enough energy to escape from the [[electric potential]] barrier that originally confined it, thus breaking the bond and freeing it to move. The amount of energy required is called the [[ionization potential]]. A negatively-charged ion is produced when a free electron collides with an atom and is subsequently caught inside the electric potential barrier, releasing any excess energy.		The process works slightly differently depending on whether an ion with a positive or a negative [[electric charge]] is being produced. A positively-charged ion is produced when an electron bonded to an atom (or molecule) absorbs enough energy to escape from the [[electric potential]] barrier that originally confined it, thus breaking the bond and freeing it to move. The amount of energy required is called the [[ionization potential]]. A negatively-charged ion is produced when a free electron collides with an atom and is subsequently caught inside the electric potential barrier, releasing any excess energy.

ClueBot: Reverting possible vandalism by 99.135.108.16 to version by Zorrobot. False positive? Report it. Thanks, ClueBot. (820450) (Bot)

Mon, 09 Nov 2009 14:50:31 -0800

Reverting possible vandalism by 99.135.108.16 to version by Zorrobot. False positive? Report it. Thanks, ClueBot. (820450) (Bot)

← Previous revision		Revision as of 22:50, 9 November 2009
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	===Applying to positive ionization===		===Applying to positive ionization===

-	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible kjxcll j and that blah lah blah!!!!!!!!!!exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.	+	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.

	===Applying to negative ionization===		===Applying to negative ionization===

99.135.108.16: /* Applying to positive ionization */

Mon, 09 Nov 2009 14:50:28 -0800

Applying to positive ionization

← Previous revision		Revision as of 22:50, 9 November 2009
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	===Applying to positive ionization===		===Applying to positive ionization===

-	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible orbital. If the energy absorbed exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.	+	According to these two principles, the energy required to release an electron is ''strictly'' greater than or equal to the potential difference between the current bound atomic or molecular [[Atomic orbital\|orbital]] and the highest possible kjxcll j and that blah lah blah!!!!!!!!!!exceeds this potential, then the electron is emitted as a free electron. Otherwise, the electron briefly enters an [[excited state]] until the energy absorbed is [[Radiation\|radiated]] out and the electron re-enters the lowest available state.

	===Applying to negative ionization===		===Applying to negative ionization===

Zorrobot: robot Adding: nn:Ionisering

Mon, 09 Nov 2009 02:05:12 -0800

robot Adding: nn:Ionisering

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	[[nl:Ionisatie]]		[[nl:Ionisatie]]
	[[no:Ionisering]]		[[no:Ionisering]]
		+	[[nn:Ionisering]]
	[[nds:Ioniseeren]]		[[nds:Ioniseeren]]
	[[pl:Jonizacja]]		[[pl:Jonizacja]]
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	[[sr:Јонизација]]		[[sr:Јонизација]]
	[[sv:Jonisering]]		[[sv:Jonisering]]
-	[[vi:Ion hóa]]
	[[tr:Yükünleşme]]		[[tr:Yükünleşme]]
	[[uk:Іонізація]]		[[uk:Іонізація]]
	[[ur:تائین]]		[[ur:تائین]]
		+	[[vi:Ion hóa]]
	[[zh:电离]]		[[zh:电离]]

128.175.138.78 at 05:42, 5 November 2009

Wed, 04 Nov 2009 21:42:38 -0800

← Previous revision		Revision as of 05:42, 5 November 2009
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	[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]		[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]
-	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).	+	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).

	The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.		The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.

128.175.138.78 at 05:41, 5 November 2009

Wed, 04 Nov 2009 21:41:28 -0800

← Previous revision		Revision as of 05:41, 5 November 2009
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	[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]		[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]
-	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).	+	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).

	The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.		The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.

Citation bot: Citation maintenance. [U56]Added: first2. Formatted: title, year, last1, first1, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

Wed, 04 Nov 2009 20:54:06 -0800

Citation maintenance. [U56]Added: first2. Formatted: title, year, last1, first1, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

← Previous revision		Revision as of 04:54, 5 November 2009
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	===Open cells===		===Open cells===
-	The most common geometry is a cylinder, which is axially segmented into different parts to produce different ring electrodes. The central ring electrode is generally used for applying radial excitation electric field and detection. DC electric voltage is applied on the terminal ring electrodes to trap ions along the magnetic field lines. Open cylindrical cells with ring electrodes of different diameters have also been designed.<ref>{{Citation \| doi = 10.1063/1.2751100 }}</ref> They proved not only capable in trapping and detecting both ion polarities simultaneously, but also they succeeded to separate positive from negative ions radially. This presented a large discrimination in kinetic ion acceleration between positive and negative ions trapped simultaneously inside the new cell. Several ion axial acceleration schemes were recently written for ion-ion collision studies <ref>{{Citation \| doi = 10.1016/j.ijms.2007.09.007}}</ref>	+	The most common geometry is a cylinder, which is axially segmented into different parts to produce different ring electrodes. The central ring electrode is generally used for applying radial excitation electric field and detection. DC electric voltage is applied on the terminal ring electrodes to trap ions along the magnetic field lines. Open cylindrical cells with ring electrodes of different diameters have also been designed.<ref>{{Cite journal \| doi = 10.1063/1.2751100 \| title = Characterization of a new open cylindrical ion cyclotron resonance cell with unusual geometry \| year = 2007 \| last1 = Kanawati \| first1 = B. \| first2 = K. P. \| journal = Review of Scientific Instruments \| volume = 78 \| pages = 074102 }}</ref> They proved not only capable in trapping and detecting both ion polarities simultaneously, but also they succeeded to separate positive from negative ions radially. This presented a large discrimination in kinetic ion acceleration between positive and negative ions trapped simultaneously inside the new cell. Several ion axial acceleration schemes were recently written for ion-ion collision studies <ref>{{Cite journal \| doi = 10.1016/j.ijms.2007.09.007 \| title = Characterization of a new open cylindrical ICR cell for ion–ion collision studies☆ \| year = 2008 \| last1 = Kanawati \| first1 = B \| first2 = K \| journal = International Journal of Mass Spectrometry \| volume = 269 \| pages = 12}}</ref>

	==Stored waveform inverse Fourier transform ==		==Stored waveform inverse Fourier transform ==

Kkmurray: /* Open cells */ ref format

Wed, 04 Nov 2009 20:51:03 -0800

Open cells: ref format

← Previous revision		Revision as of 04:51, 5 November 2009
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	===Open cells===		===Open cells===
-		+	The most common geometry is a cylinder, which is axially segmented into different parts to produce different ring electrodes. The central ring electrode is generally used for applying radial excitation electric field and detection. DC electric voltage is applied on the terminal ring electrodes to trap ions along the magnetic field lines. Open cylindrical cells with ring electrodes of different diameters have also been designed.<ref>{{Citation \| doi = 10.1063/1.2751100 }}</ref> They proved not only capable in trapping and detecting both ion polarities simultaneously, but also they succeeded to separate positive from negative ions radially. This presented a large discrimination in kinetic ion acceleration between positive and negative ions trapped simultaneously inside the new cell. Several ion axial acceleration schemes were recently written for ion-ion collision studies <ref>{{Citation \| doi = 10.1016/j.ijms.2007.09.007}}</ref>
-	The most common geometry is a cylinder, which is axially segmented into different parts to produce different ring electrodes. The central ring electrode is generally used for applying radial excitation electric field and detection. DC electric voltage is applied on the terminal ring electrodes to trap ions along the magnetic field lines. Open cylindrical cells with ring electrodes of different diameters have also been designed <ref>[http://dx.doi.org/10.1063/1.2751100 B. Kanawati, K. P. Wanczek, Characterisation of a New Open Cylindrical ICR Cell with unusual geometry. Rev. Sci. Instrum. (2007), 78, 7, 074102]</ref>. They proved not only capable in trapping and detecting both ion polarities simultaneously, but also they succeeded to separate positive from negative ions radially. This presented a large discrimination in kinetic ion acceleration between positive and negative ions trapped simultaneously inside the new cell. Several ion axial acceleration schemes were recently written for ion-ion collision studies <ref>[http://dx.doi.org/10.1016/j.ijms.2007.09.007 B. Kanawati, K. P. Wanczek, Characterisation of a New Open Cylindrical ICR Cell for Ion-Ion Collision Studies, Int. J. Mass Spectrom. (2007), in press. DOI:10.1016/j.ijms.2007.09.007]</ref>.

	==Stored waveform inverse Fourier transform ==		==Stored waveform inverse Fourier transform ==

Citation bot: Citation maintenance. [U56]Formatted: doi, title, year, last1, first1, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

Wed, 04 Nov 2009 20:44:18 -0800

Citation maintenance. [U56]Formatted: doi, title, year, last1, first1, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

← Previous revision		Revision as of 04:44, 5 November 2009
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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (''m/z'') to be detected as distinct ions.<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref name="pmid12033259">{{cite journal \|author=Bossio RE, Marshall AG \|title=Baseline resolution of isobaric phosphorylated and sulfated peptides and nucleotides by electrospray ionization FTICR ms: another step toward mass spectrometry-based proteomics \|journal=[[Anal. Chem.]] \|volume=74 \|issue=7 \|pages=1674–9 \|year=2002 \|month=April \|pmid=12033259 \|doi= \|url=}}</ref><ref name="pmid11217775">{{cite journal \|author=He F, Hendrickson CL, Marshall AG \|title=Baseline mass resolution of peptide isobars: a record for molecular mass resolution \|journal=[[Anal. Chem.]] \|volume=73 \|issue=3 \|pages=647–50 \|year=2001 \|month=February \|pmid=11217775 \|doi= \|url=}}</ref> This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]]. For example, attomole level of detection of two peptides has been reported .<ref name="pmid8633766">{{cite journal \|author=Solouki T, Marto JA, White FM, Guan S, Marshall AG \|title=Attomole biomolecule mass analysis by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance \|journal=[[Anal. Chem.]] \|volume=67 \|issue=22 \|pages=4139–44 \|year=1995 \|month=November \|pmid=8633766 \|doi= \|url=}}</ref> These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Cite journal \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (''m/z'') to be detected as distinct ions.<ref name="pmid15694769">{{Cite journal \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref name="pmid12033259">{{cite journal \|author=Bossio RE, Marshall AG \|title=Baseline resolution of isobaric phosphorylated and sulfated peptides and nucleotides by electrospray ionization FTICR ms: another step toward mass spectrometry-based proteomics \|journal=[[Anal. Chem.]] \|volume=74 \|issue=7 \|pages=1674–9 \|year=2002 \|month=April \|pmid=12033259 \|doi= 10.1021/ac0108461\|url=}}</ref><ref name="pmid11217775">{{cite journal \|author=He F, Hendrickson CL, Marshall AG \|title=Baseline mass resolution of peptide isobars: a record for molecular mass resolution \|journal=[[Anal. Chem.]] \|volume=73 \|issue=3 \|pages=647–50 \|year=2001 \|month=February \|pmid=11217775 \|doi= 10.1021/ac000973h\|url=}}</ref> This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]]. For example, attomole level of detection of two peptides has been reported .<ref name="pmid8633766">{{cite journal \|author=Solouki T, Marto JA, White FM, Guan S, Marshall AG \|title=Attomole biomolecule mass analysis by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance \|journal=[[Anal. Chem.]] \|volume=67 \|issue=22 \|pages=4139–44 \|year=1995 \|month=November \|pmid=8633766 \|doi= 10.1021/ac00118a017\|url=}}</ref> These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

-	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter.<ref>{{Citation \| doi = 10.1016/S1387-3806(01)00588-7 }}</ref>	+	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter.<ref>{{Cite journal \| doi = 10.1016/S1387-3806(01)00588-7 \| title = Fourier transform ion cyclotron resonance detection: principles and experimental configurations \| year = 2002 \| last1 = Marshall \| first1 = A \| journal = International Journal of Mass Spectrometry \| volume = 215 \| pages = 59 }}</ref>

	==History==		==History==
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	==Stored waveform inverse Fourier transform ==		==Stored waveform inverse Fourier transform ==
-	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{citation \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = [[Rapid Communications in Mass Spectrometry]] \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607 \| first2 = R. E. \| first3 = S. D. \| first4 = Alan G.}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.	+	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{Cite journal \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = [[Rapid Communications in Mass Spectrometry]] \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607 \| first2 = R. E. \| first3 = S. D. \| first4 = Alan G.}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.

	==See also==		==See also==

Kkmurray: ref format

Wed, 04 Nov 2009 20:43:04 -0800

ref format

← Previous revision		Revision as of 04:43, 5 November 2009
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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (''m/z'') to be detected as distinct ions.<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref name="pmid12033259">{{cite journal \|author=Bossio RE, Marshall AG \|title=Baseline resolution of isobaric phosphorylated and sulfated peptides and nucleotides by electrospray ionization FTICR ms: another step toward mass spectrometry-based proteomics \|journal=[[Anal. Chem.]] \|volume=74 \|issue=7 \|pages=1674–9 \|year=2002 \|month=April \|pmid=12033259 \|doi= \|url=}}</ref><ref name="pmid11217775">{{cite journal \|author=He F, Hendrickson CL, Marshall AG \|title=Baseline mass resolution of peptide isobars: a record for molecular mass resolution \|journal=[[Anal. Chem.]] \|volume=73 \|issue=3 \|pages=647–50 \|year=2001 \|month=February \|pmid=11217775 \|doi= \|url=}}</ref> This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]]. For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (''m/z'') to be detected as distinct ions.<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref name="pmid12033259">{{cite journal \|author=Bossio RE, Marshall AG \|title=Baseline resolution of isobaric phosphorylated and sulfated peptides and nucleotides by electrospray ionization FTICR ms: another step toward mass spectrometry-based proteomics \|journal=[[Anal. Chem.]] \|volume=74 \|issue=7 \|pages=1674–9 \|year=2002 \|month=April \|pmid=12033259 \|doi= \|url=}}</ref><ref name="pmid11217775">{{cite journal \|author=He F, Hendrickson CL, Marshall AG \|title=Baseline mass resolution of peptide isobars: a record for molecular mass resolution \|journal=[[Anal. Chem.]] \|volume=73 \|issue=3 \|pages=647–50 \|year=2001 \|month=February \|pmid=11217775 \|doi= \|url=}}</ref> This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]]. For example, attomole level of detection of two peptides has been reported .<ref name="pmid8633766">{{cite journal \|author=Solouki T, Marto JA, White FM, Guan S, Marshall AG \|title=Attomole biomolecule mass analysis by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance \|journal=[[Anal. Chem.]] \|volume=67 \|issue=22 \|pages=4139–44 \|year=1995 \|month=November \|pmid=8633766 \|doi= \|url=}}</ref> These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

-	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.	+	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter.<ref>{{Citation \| doi = 10.1016/S1387-3806(01)00588-7 }}</ref>

	==History==		==History==
Line 62:		Line 62:

	==Stored waveform inverse Fourier transform ==		==Stored waveform inverse Fourier transform ==
-	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{citation \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = Rapid Communications in Mass Spectrometry \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607 \| first2 = R. E. \| first3 = S. D. \| first4 = Alan G.}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.	+	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{citation \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = [[Rapid Communications in Mass Spectrometry]] \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607 \| first2 = R. E. \| first3 = S. D. \| first4 = Alan G.}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.

	==See also==		==See also==

Kkmurray: format refs

Wed, 04 Nov 2009 20:35:33 -0800

format refs

← Previous revision		Revision as of 04:35, 5 November 2009
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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (''m/z'') to be detected as distinct ions.<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref name="pmid12033259">{{cite journal \|author=Bossio RE, Marshall AG \|title=Baseline resolution of isobaric phosphorylated and sulfated peptides and nucleotides by electrospray ionization FTICR ms: another step toward mass spectrometry-based proteomics \|journal=[[Anal. Chem.]] \|volume=74 \|issue=7 \|pages=1674–9 \|year=2002 \|month=April \|pmid=12033259 \|doi= \|url=}}</ref><ref name="pmid11217775">{{cite journal \|author=He F, Hendrickson CL, Marshall AG \|title=Baseline mass resolution of peptide isobars: a record for molecular mass resolution \|journal=[[Anal. Chem.]] \|volume=73 \|issue=3 \|pages=647–50 \|year=2001 \|month=February \|pmid=11217775 \|doi= \|url=}}</ref> This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]]. For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.		FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.

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	==History==		==History==
-	FT-ICR was invented by [[Alan G. Marshall]] and [http://www.chem.ubc.ca/personnel/faculty/comisarow/ Melvin B. Comisarow] at the University of British Columbia. The first paper appeared in [[Chemical Physics Letters]] in 1974.<ref>[http://dx.doi.org/10.1016/0009-2614(74)89137-2 M.B. Comisarow and A.G. Marshall, ''Chem. Phys. Lett.'' '''25''', 282 (1974)]</ref> The inspiration was earlier developments in conventional ICR and Fourier Transform Nuclear Magnetic Resonance (FT-NMR) spectroscopy. Marshall has continued to develop the technique at The Ohio State University and Florida State University.	+	FT-ICR was invented by [[Alan G. Marshall]] and Melvin B. Comisarow<ref> {{cite web\|url=http://www.chem.ubc.ca/personnel/faculty/comisarow/ \|title=UBC Chemistry Personnel: Melvin B. Comisarow \|accessdate=2009-11-05 \|publisher=University of British Columbia }}</ref> at the University of British Columbia. The first paper appeared in [[Chemical Physics Letters]] in 1974.<ref>[http://dx.doi.org/10.1016/0009-2614(74)89137-2 M.B. Comisarow and A.G. Marshall, ''Chem. Phys. Lett.'' '''25''', 282 (1974)]</ref> The inspiration was earlier developments in conventional ICR and Fourier Transform Nuclear Magnetic Resonance (FT-NMR) spectroscopy. Marshall has continued to develop the technique at The Ohio State University and Florida State University.
-
-
-

	==Theory==		==Theory==

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Wed, 04 Nov 2009 20:22:51 -0800

Citation maintenance. [U56]Added: title, year, last1, first1, journal, volume, pages, first2, first3, first4. Unified citation types. You can use this bot yourself! Please report any bugs.

← Previous revision		Revision as of 04:22, 5 November 2009
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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{cite journal \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 \| title = Comparison and interconversion of the two most common frequency-to-mass calibration functions for Fourier transform ion cyclotron resonance mass spectrometry \| year = 2000 \| last1 = Shi \| first1 = S \| journal = International Journal of Mass Spectrometry \| volume = 195-196 \| pages = 591 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{Citation \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.		FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.
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	==Stored waveform inverse Fourier transform ==		==Stored waveform inverse Fourier transform ==
-	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{citation \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = Rapid Communications in Mass Spectrometry \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.	+	Stored waveform inverse Fourier transform (SWIFT) is a method for the creation of excitation waveforms for FTMS.<ref name=Cody1987>{{citation \| last = Cody \| first = R. B. \| year = 1987 \| title = Stored waveform inverse fourier transform excitation for obtaining increased parent ion selectivity in collisionally activated dissociation: Preliminary results \| journal = Rapid Communications in Mass Spectrometry \| volume = 1 \| pages = 99 \| doi = 10.1002/rcm.1290010607 \| first2 = R. E. \| first3 = S. D. \| first4 = Alan G.}}</ref> The time-domain excitation waveform is formed from the inverse Fourier transform of the appropriate frequency-domain excitation spectrum, which is chosen to excite the resonance frequencies of selected ions. The SWIFT procedure can be used to select ions for [[tandem mass spectrometry]] experiments.

	==See also==		==See also==

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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage <ref> see for discussion: Shi et al., IJMS 195/196: 591-598 (2000) </ref>. Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{cite journal \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage.<ref>{{Citation \| doi = 10.1016/S1387-3806(99)00226-2 }}</ref> Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{cite journal \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.		FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.

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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage <ref> see for discussion: Shi et al., IJMS 195/196: 591-598 (2000) </ref>. Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions <ref> see Sleno et al., JASMS 16:183-198 (2004)</ref>. <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage <ref> see for discussion: Shi et al., IJMS 195/196: 591-598 (2000) </ref>. Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions .<ref name="pmid15694769">{{cite journal \|author=Sleno L, Volmer DA, Marshall AG \|title=Assigning product ions from complex MS/MS spectra: the importance of mass uncertainty and resolving power \|journal=[[J. Am. Soc. Mass Spectrom.]] \|volume=16 \|issue=2 \|pages=183–98 \|year=2005 \|month=February \|pmid=15694769 \|doi=10.1016/j.jasms.2004.10.001 \|url=}}</ref> <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.		FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.

Guyler at 21:57, 4 November 2009

Wed, 04 Nov 2009 13:57:26 -0800

← Previous revision		Revision as of 21:57, 4 November 2009
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	'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].		'''Fourier transform ion cyclotron resonance mass spectrometry''', also known as '''Fourier transform mass spectrometry''', is a type of mass analyzer (or [[mass spectrometer]]) for determining the [[mass-to-charge ratio]] (m/z) of [[ions]] based on the [[ion cyclotron resonance\|cyclotron frequency]] of the ions in a fixed magnetic field.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9768511 Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S., Fourier transform ion cyclotron resonance mass spectrometry: a primer. ''Mass Spectrom Rev'' '''17''', 1-35.]</ref> The ions are trapped in a [[Penning trap]] (a magnetic field with electric trapping plates) where they are excited to a larger cyclotron radius by an oscillating electric field perpendicular to the magnetic field. The excitation also results in the ions moving in phase (in a packet). The signal is detected as an image current on a pair of plates which the packet of ions passes close to as they cyclotron. The resulting signal is called a [[free induction decay]] (FID), transient or interferogram that consists of a superposition of [[sine waves]]. The useful signal is extracted from this data by performing a [[Fourier transform]] to give a [[mass spectrum]].

-	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage <ref> see for discussion: Shi et al., IJMS 195/196: 591-598 (2000) </ref>. Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions <ref> see Sleno et al., JASMS 16:183-198 (2004)</ref>. For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 <ref> Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003 </ref>. Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR <ref> He et al., Anal. Chem. 73:647-650, 2001 </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>.These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.	+	Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a very high resolution technique in that masses can be determined with very high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the [[mass defect]] of the elements. FT-ICR MS is able to achieve higher levels of resolution than other forms of mass spectrometry, in part, because a superconducting magnet is much more stable than rf voltage <ref> see for discussion: Shi et al., IJMS 195/196: 591-598 (2000) </ref>. Another place that FTICR-MS is useful is in dealing with complex mixtures since the resolution (narrow peak width) allows the signals of two ions of similar mass to charge (m/z) to be detected as distinct ions <ref> see Sleno et al., JASMS 16:183-198 (2004)</ref>. <ref> For example, two peptides that differ only in their post-translational modification at the same site can be uniquely identified by FT-ICR: DY(PO3H2)MGWMDF-NH2 & DY(SO3H)MGWMDF-NH2 (Bossio and Marshall, Anal. Chem. 74:1674-1679, 2003). Also, two peptides with a mass difference of 0.000 45 Daltons) can be identified in the same mixture: RVMRGMR & RSHRGHR (He et al., Anal. Chem. 73:647-650, 2001) </ref>. This high resolution is also useful in studying large macromolecules such as proteins with multiple charges which can be produced by [[electrospray ionization]].For example, attomole level of detection of two peptides has been reported <ref> Solouki et al., Anal. Chem. 67:4139-4144, 1995 </ref>. These large molecules contain a distribution of [[isotopes]] that produce a series of isotopic peaks. Because the isotopic peaks are close to each other on the ''m/z'' axis, due to the multiple charges, the high resolving power of the FTICR is extremely useful.

	FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.		FTICR-MS differs significantly from other [[mass spectrometry]] techniques in that the ions are not detected by hitting a detector such as an [[electron multiplier]] but only by passing near detection plates. Additionally the masses are not resolved in space or time as with other techniques but only by the cyclotron (rotational) frequency that each ion produces as it rotates in a magnetic field. Thus, the different ions are not detected in different places as with [[sector instrument]]s or at different times as with [[time-of-flight]] instruments but all ions are detected simultaneously over some given period of time. In FT-ICR MS, resolution can be improved by increasing the strength of the magnet (in teslas) and by increasing the magnets bore diameter <ref> Marshall et al., IJMS 215:59-75, 2002 </ref>.

Guyler: addition of IR MALDI Cite

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-	Loss of sialic acid has been identified in papers when DHB has been used as a matrix for MALDI MS analysis of glycosylated peptides. Using sinapinic acid, 4-HCCA and DHB as matrices, Dr. Martin studied loss of sialic acid in glycosylated peptides by metastable decay in MALDI/TOF in linear mode and reflector mode <ref> Huberty et al., Anal. Chem. 65:2791-2800, 1993 </ref>. A group at SHIMIZU CORPORATION proposed derivitizing the sialic acid by an amidation reaction as a way to improve results <ref> Sekiya et al., Anal. Chem. 77:4962-4968, 2005 </ref> and also proposed use of an Ionic liquid matrix to reduce loss of sialic acid during MALDI/TOF MS analysis of sialylated oligosaccharides <ref> Fukuyama et al., Anal. Chem. 80:2171-2179, 2008 </ref>. THAP <ref> Papac et al., Anal. Chem. 68:3215-3223, 1996 </ref>, DHAP <ref> Harvey Mass Spectrometry Reviews 18: 349-451, 1999 </ref>, and a mixture of 2-aza-2-thiothymine and phenylhydrazine <ref> Lattova et al., Rapid Communications in Mass Spectrometry 21: 1644-1650, 2007 </ref> have been identified as matrices that could be used to minimize loss of sialic acid during MALDI MS analysis of glycosylated peptides.	+	Loss of sialic acid has been identified in papers when DHB has been used as a matrix for MALDI MS analysis of glycosylated peptides. Using sinapinic acid, 4-HCCA and DHB as matrices, Dr. Martin studied loss of sialic acid in glycosylated peptides by metastable decay in MALDI/TOF in linear mode and reflector mode <ref> Huberty et al., Anal. Chem. 65:2791-2800, 1993 </ref>. A group at SHIMIZU CORPORATION proposed derivitizing the sialic acid by an amidation reaction as a way to improve results <ref> Sekiya et al., Anal. Chem. 77:4962-4968, 2005 </ref> and also proposed use of an Ionic liquid matrix to reduce loss of sialic acid during MALDI/TOF MS analysis of sialylated oligosaccharides <ref> Fukuyama et al., Anal. Chem. 80:2171-2179, 2008 </ref>. THAP <ref> Papac et al., Anal. Chem. 68:3215-3223, 1996 </ref>, DHAP <ref> Harvey Mass Spectrometry Reviews 18: 349-451, 1999 </ref>, and a mixture of 2-aza-2-thiothymine and phenylhydrazine <ref> Lattova et al., Rapid Communications in Mass Spectrometry 21: 1644-1650, 2007 </ref> have been identified as matrices that could be used to minimize loss of sialic acid during MALDI MS analysis of glycosylated peptides.
		+
		+	It has been reported that a reduction in loss of some post-translational modifications can be accomplished if IR MALDI is used instead of UV MALDI <ref> Tajiri et al.,Anal. Chem. 81:6750-6755, 2009 </Ref>

	===In Organic Chemistry===		===In Organic Chemistry===

Peteronium at 12:09, 1 November 2009

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	===Drug development===		===Drug development===
-	LC-MS is frequently used in drug development at many different stages including Peptide Mapping, Glycoprotein Mapping, Natural Products Dereplication, Bioaffinity Screening, In Vivo Drug Screening, Metabolic Stability Screening, Metabolite Identification, Impurity Identification, Degradant Identification, Quantitative Bioanalysis, and Quality Control.<ref>[http://www3.interscience.wiley.com/cgi-bin/abstract/66004558/ABSTRACT LC/MS applications in drug development, Mass Spectrometry Reviews, Mike S. Lee, Edward H. Kerns, Vol 18, 1999, pp 187-279]</ref>	+	LC-MS is frequently used in drug development at many different stages including Peptide Mapping, Glycoprotein Mapping, Natural Products Dereplication, Bioaffinity Screening, In Vivo Drug Screening, Metabolic Stability Screening, Metabolite Identification, Impurity Identification, Degradant Identification, Quantitative [[Bioanalysis]], and Quality Control.<ref>[http://www3.interscience.wiley.com/cgi-bin/abstract/66004558/ABSTRACT LC/MS applications in drug development, Mass Spectrometry Reviews, Mike S. Lee, Edward H. Kerns, Vol 18, 1999, pp 187-279]</ref>

	==See also==		==See also==

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	[[Atom probe]] tomography also takes advantage of TOF mass spectrometry.		[[Atom probe]] tomography also takes advantage of TOF mass spectrometry.
-
-	== Manufacturers==
-	* [[Jeol]]
-	* [[LECO Corporation]]
-	* [http://www.gbcsci.com GBC Scientific Equipment]

	== See also ==		== See also ==
	[[Bradbury-Nielsen shutter]]		[[Bradbury-Nielsen shutter]]
		+
		+	=== Manufacturers===
		+	* [[Jeol]]
		+	* [[LECO Corporation]]

	== References ==		== References ==

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Manufacturers

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	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
-	* [[http://www.gbcsci.com GBC Scientific Equipment]]	+	* [http://www.gbcsci.com GBC Scientific Equipment]

	== See also ==		== See also ==

Lamarck001: /* Manufacturers */

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Manufacturers

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	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
		+	* [[http://www.gbcsci.com GBC Scientific Equipment]]

	== See also ==		== See also ==

TinucherianBot II: robot Modifying: it:Gascromatografia - spettrometria di massa

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robot Modifying: it:Gascromatografia - spettrometria di massa

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	[[de:Gaschromatographie mit Massenspektrometrie-Kopplung]]		[[de:Gaschromatographie mit Massenspektrometrie-Kopplung]]
-	[[it:GC-MS]]	+	[[it:Gascromatografia - spettrometria di massa]]

Citation bot: Citation maintenance. [U56]Added: first2, first3, last1, first1, pmc. Formatted: title, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

Thu, 22 Oct 2009 20:05:28 -0700

Citation maintenance. [U56]Added: first2, first3, last1, first1, pmc. Formatted: title, journal, volume, pages. Unified citation types. You can use this bot yourself! Please report any bugs.

Kkmurray: /* Matrix */ add doi's

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	The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:		The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:
	* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.		* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.
-	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993)</ref>.	+	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993){{Citation \| doi = 10.1021/ac00070a007}}</ref>.
-	* They have a strong optical absorption in either the UV or IR range, <ref>Zenobi and Knochenmuss Mass Spectrometry Reviews 17: 337-366, 1998 </ref> so that they rapidly and efficiently absorb the laser irradiation.	+	* They have a strong optical absorption in either the UV or IR range, <ref>Zenobi and Knochenmuss Mass Spectrometry Reviews 17: 337-366, 1998 {{Citation \| doi = 10.1002/(SICI)1098-2787(1998)17:5<337::AID-MAS2>3.0.CO;2-S}}</ref> so that they rapidly and efficiently absorb the laser irradiation.
	* They are functionalized with polar groups, allowing their use in aqueous solutions.		* They are functionalized with polar groups, allowing their use in aqueous solutions.

Guyler at 19:10, 22 October 2009

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-	Loss of sialic acid has been identified in papers when DHB has been used as a matrix for MALDI MS analysis of glycosylated peptides. Using sinapinic acid, 4-HCCA and DHB as matrices, Dr. Martin studied loss of sialic acid in glycosylated peptides by metastable decay in MALDI/TOF in linear mode and reflector mode <ref> Huberty et al., Anal. Chem. 65:2791-2800, 1993 </ref>. A group at SHIMIZU CORPORATION proposed derivitizing the sialic acid by an amidation reaction as a way to improve results <ref> Sekiya et al., Anal. Chem. 77:4962-4968, 2005 </ref> and also proposed use of an Ionic liquid matrix to reduce loss of sialic acid during MALDI/TOF MS analysis of sialylated oligosaccharides <ref> Fukuyama et al., Anal. Chem. 80:2171-2179, 2008 </ref>. THAP <ref> Papac et al., Anal. Chem. 68:3215-3223, 1996 </ref>, DHAP <ref> Harvey Mass Spectrometry Reviews 18: 349-451, 1999 </ref>, and a mixture of 2-aza-2-thiothymine andphenylhydrazine <ref> Lattova et al., Rapid Communications in Mass Spectrometry 21: 1644-1650, 2007 </ref> have been identified as matrices that could be used to minimize loss of sialic acid during MALDI MS analysis of glycosylated peptides.	+	Loss of sialic acid has been identified in papers when DHB has been used as a matrix for MALDI MS analysis of glycosylated peptides. Using sinapinic acid, 4-HCCA and DHB as matrices, Dr. Martin studied loss of sialic acid in glycosylated peptides by metastable decay in MALDI/TOF in linear mode and reflector mode <ref> Huberty et al., Anal. Chem. 65:2791-2800, 1993 </ref>. A group at SHIMIZU CORPORATION proposed derivitizing the sialic acid by an amidation reaction as a way to improve results <ref> Sekiya et al., Anal. Chem. 77:4962-4968, 2005 </ref> and also proposed use of an Ionic liquid matrix to reduce loss of sialic acid during MALDI/TOF MS analysis of sialylated oligosaccharides <ref> Fukuyama et al., Anal. Chem. 80:2171-2179, 2008 </ref>. THAP <ref> Papac et al., Anal. Chem. 68:3215-3223, 1996 </ref>, DHAP <ref> Harvey Mass Spectrometry Reviews 18: 349-451, 1999 </ref>, and a mixture of 2-aza-2-thiothymine and phenylhydrazine <ref> Lattova et al., Rapid Communications in Mass Spectrometry 21: 1644-1650, 2007 </ref> have been identified as matrices that could be used to minimize loss of sialic acid during MALDI MS analysis of glycosylated peptides.

	===In Organic Chemistry===		===In Organic Chemistry===

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	===In Biochemistry===		===In Biochemistry===
	In [[proteomics]], MALDI is used for the identification of proteins isolated through [[gel electrophoresis]]: [[SDS-PAGE]], [[size exclusion chromatography]], and [[two-dimensional gel electrophoresis]]. One method used is [[peptide mass fingerprinting]] by MALDI-MS, or with [[post ionisation decay]] or [[collision-induced dissociation]] (further use see [[mass spectrometry]]).		In [[proteomics]], MALDI is used for the identification of proteins isolated through [[gel electrophoresis]]: [[SDS-PAGE]], [[size exclusion chromatography]], and [[two-dimensional gel electrophoresis]]. One method used is [[peptide mass fingerprinting]] by MALDI-MS, or with [[post ionisation decay]] or [[collision-induced dissociation]] (further use see [[mass spectrometry]]).
		+
		+
		+	Loss of sialic acid has been identified in papers when DHB has been used as a matrix for MALDI MS analysis of glycosylated peptides. Using sinapinic acid, 4-HCCA and DHB as matrices, Dr. Martin studied loss of sialic acid in glycosylated peptides by metastable decay in MALDI/TOF in linear mode and reflector mode <ref> Huberty et al., Anal. Chem. 65:2791-2800, 1993 </ref>. A group at SHIMIZU CORPORATION proposed derivitizing the sialic acid by an amidation reaction as a way to improve results <ref> Sekiya et al., Anal. Chem. 77:4962-4968, 2005 </ref> and also proposed use of an Ionic liquid matrix to reduce loss of sialic acid during MALDI/TOF MS analysis of sialylated oligosaccharides <ref> Fukuyama et al., Anal. Chem. 80:2171-2179, 2008 </ref>. THAP <ref> Papac et al., Anal. Chem. 68:3215-3223, 1996 </ref>, DHAP <ref> Harvey Mass Spectrometry Reviews 18: 349-451, 1999 </ref>, and a mixture of 2-aza-2-thiothymine andphenylhydrazine <ref> Lattova et al., Rapid Communications in Mass Spectrometry 21: 1644-1650, 2007 </ref> have been identified as matrices that could be used to minimize loss of sialic acid during MALDI MS analysis of glycosylated peptides.

	===In Organic Chemistry===		===In Organic Chemistry===

Guyler: adding reference

Thu, 22 Oct 2009 10:50:19 -0700

adding reference

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	* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.		* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.
	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993)</ref>.		* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993)</ref>.
-	* They have a strong optical absorption in the UV, so that they rapidly and efficiently absorb the laser irradiation.	+	* They have a strong optical absorption in either the UV or IR range, <ref>Zenobi and Knochenmuss Mass Spectrometry Reviews 17: 337-366, 1998 </ref> so that they rapidly and efficiently absorb the laser irradiation.
	* They are functionalized with polar groups, allowing their use in aqueous solutions.		* They are functionalized with polar groups, allowing their use in aqueous solutions.

Vsmith: Reverted edits by 83.78.29.153 (talk) to last version by Kkmurray

Wed, 21 Oct 2009 04:10:13 -0700

Reverted edits by 83.78.29.153 (talk) to last version by Kkmurray

← Previous revision		Revision as of 11:10, 21 October 2009
Line 61:		Line 61:
	* Can harmonic generation cause non-sequential ionization? J. Phys. B: At. Mol. Opt. Phys. 31 No 19 (14 October 1998) L841-L848.		* Can harmonic generation cause non-sequential ionization? J. Phys. B: At. Mol. Opt. Phys. 31 No 19 (14 October 1998) L841-L848.
	* Probing atomic ionization mechanisms in intense laser fields by calculating geometry and diffraction independent ionization probabilities. J Wood, E M L English, S L Stebbings, W A Bryan, W R *Newell, J McKenna, M Suresh, B Srigengan, I D Williams, I C E Turcu, J M Smith, K G Ertel, E J Divall, C J Hooker, A J Langley. {{PDFlink\|http://www.clf.rl.ac.uk/Reports/2004-2005/pdf/26.pdf\|217 [[Kibibyte\|KiB]]<!-- application/pdf, 223112 bytes -->}}		* Probing atomic ionization mechanisms in intense laser fields by calculating geometry and diffraction independent ionization probabilities. J Wood, E M L English, S L Stebbings, W A Bryan, W R *Newell, J McKenna, M Suresh, B Srigengan, I D Williams, I C E Turcu, J M Smith, K G Ertel, E J Divall, C J Hooker, A J Langley. {{PDFlink\|http://www.clf.rl.ac.uk/Reports/2004-2005/pdf/26.pdf\|217 [[Kibibyte\|KiB]]<!-- application/pdf, 223112 bytes -->}}
-	XD	+
	[[Category:Ions]]		[[Category:Ions]]
	[[Category:Molecular physics]]		[[Category:Molecular physics]]

Dragnmn: /* Matrix */

Wed, 21 Oct 2009 01:26:02 -0700

Matrix

← Previous revision		Revision as of 08:26, 21 October 2009
Line 33:		Line 33:
	The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:		The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:
	* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.		* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.
-	* They are ofton acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993)</ref>.	+	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993)</ref>.
	* They have a strong optical absorption in the UV, so that they rapidly and efficiently absorb the laser irradiation.		* They have a strong optical absorption in the UV, so that they rapidly and efficiently absorb the laser irradiation.
	* They are functionalized with polar groups, allowing their use in aqueous solutions.		* They are functionalized with polar groups, allowing their use in aqueous solutions.

JaGa: Disambiguate Constant to Constant (mathematics) using popups

Tue, 20 Oct 2009 15:21:24 -0700

Disambiguate Constant to Constant (mathematics) using popups

← Previous revision		Revision as of 22:21, 20 October 2009
Line 38:		Line 38:
	:<math>t = \frac{d}{\sqrt{2U}} \sqrt{\frac{m}{q}}\,</math> [8]		:<math>t = \frac{d}{\sqrt{2U}} \sqrt{\frac{m}{q}}\,</math> [8]

-	These factors for the time of flight have been grouped purposely. <math>\frac{d}{\sqrt{2U}}</math> contains [[constant]]s that in principle do not change when a set of ions are analyzed in a single pulse of [[acceleration]]. Eqn 8 can thus be given as:	+	These factors for the time of flight have been grouped purposely. <math>\frac{d}{\sqrt{2U}}</math> contains [[Constant (mathematics)\|constant]]s that in principle do not change when a set of ions are analyzed in a single pulse of [[acceleration]]. Eqn 8 can thus be given as:

	:<math>t = k \sqrt{\frac{m}{q}}\,</math> [9]		:<math>t = k \sqrt{\frac{m}{q}}\,</math> [9]

Guyler at 15:12, 20 October 2009

Tue, 20 Oct 2009 08:12:09 -0700

← Previous revision		Revision as of 15:12, 20 October 2009
Line 57:		Line 57:

	MALDI has been coupled with IMS-TOF MS to identify phoshorylated and non-phosphorylated peptides <ref> Ruotolo et al., Anal. Chem. 76:6727-6733, 2004; Ruotolo et al., Journal of Proteome Research 1:303-306, 2002 </ref>.		MALDI has been coupled with IMS-TOF MS to identify phoshorylated and non-phosphorylated peptides <ref> Ruotolo et al., Anal. Chem. 76:6727-6733, 2004; Ruotolo et al., Journal of Proteome Research 1:303-306, 2002 </ref>.
-

	MALDI-FT-ICR MS has been demonstrated to be a useful technique where high resolution MALDI-MS measurements are desired <ref> Pasa-Tolic et al., Journal of Mass Spectrometry 30:825-833, 1995 </ref>.		MALDI-FT-ICR MS has been demonstrated to be a useful technique where high resolution MALDI-MS measurements are desired <ref> Pasa-Tolic et al., Journal of Mass Spectrometry 30:825-833, 1995 </ref>.

87.16.87.230: /* External links */

Mon, 19 Oct 2009 17:04:46 -0700

External links

← Previous revision		Revision as of 00:04, 20 October 2009
Line 130:		Line 130:

	[[de:Gaschromatographie mit Massenspektrometrie-Kopplung]]		[[de:Gaschromatographie mit Massenspektrometrie-Kopplung]]
		+	[[it:GC-MS]]

Kkmurray: /* Manufacturers */ rm red link

Thu, 08 Oct 2009 08:17:21 -0700

Manufacturers: rm red link

← Previous revision		Revision as of 15:17, 8 October 2009
Line 106:		Line 106:
	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
-	* [[GBC Scientific]]

	== See also ==		== See also ==

87.197.111.201: /* Manufacturers */

Wed, 07 Oct 2009 02:07:20 -0700

Manufacturers

← Previous revision		Revision as of 09:07, 7 October 2009
Line 106:		Line 106:
	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
		+	* [[GBC Scientific]]

	== See also ==		== See also ==

GraemeLeggett: copyedit

Tue, 06 Oct 2009 08:39:08 -0700

copyedit

← Previous revision		Revision as of 15:39, 6 October 2009
Line 1:		Line 1:
-	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for volatile [[organic chemistry\|organic]] molecules.	+	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for gases and volatile [[organic chemistry\|organic molecules]].

	==Principle of operation==		==Principle of operation==
Line 11:		Line 11:
	where M is the analyte molecule being ionized, e<sup>-</sup> is the electron and M<sup>+•</sup> is the resulting ion.		where M is the analyte molecule being ionized, e<sup>-</sup> is the electron and M<sup>+•</sup> is the resulting ion.

-	In an EI ion source, electrons are produced through [[thermionic emission]] by heating a wire filament that has [[Current (electricity)\|electric current]] running through it. The electrons are accelerated to 70 eV in the region between the filament and the entrance to the ion source block. The accelerated electrons are then concentrated into a beam by being attracted to the trap electrode. A sample vapour containing the neutral molecules is introduced to the ion source in a perpendicular direction to the e- beam. Upon interaction with the e- beam, the analyte molecules ionize to [[radical ion\|radical cations]] which are then directed towards the mass analyzer by a repeller electrode. Due to the high energy electrons and the initial thermal distribution of the neutral molecules, the ionization process frequently causes cleavage reactions that give rise to fragment ions, which can convey structural information about the analyte.	+	In an EI ion source, electrons are produced through [[thermionic emission]] by heating a wire filament that has [[Current (electricity)\|electric current]] running through it. The electrons are accelerated to 70 eV in the region between the filament and the entrance to the ion source block. The accelerated electrons are then concentrated into a beam by being attracted to the trap electrode. The sample under investigation which contains the neutral molecules is introduced to the ion source in a perpendicular direction to the e- beam. Upon interaction with the e- beam, the analyte molecules ionize to [[radical ion\|radical cations]] which are then directed towards the mass analyzer by a repeller electrode. Due to the high energy electrons and the initial thermal distribution of the neutral molecules, the ionization process frequently causes cleavage reactions that give rise to fragment ions, which can convey structural information about the analyte.
-

	The ionization efficiency and production of fragment ions depends strongly on the chemistry of the analyte and the [[energy]] of the electrons. At low energies (around 20 [[Electronvolt\|eV]]), the interactions between the electrons and the analyte molecules do not transfer enough energy to cause ionization. At around 70 eV, the [[Louis-Victor de Broglie\|de Broglie]] [[wavelength]] of the electrons matches the length of typical bonds in organic molecules (about 0.14 nm) and energy transfer to organic analyte molecules is maximized, leading to the strongest possible ionization and fragmentation. Under these conditions, about 1 in 1000 analyte molecules in the source are ionized. At higher energies, the de Broglie wavelength of the electrons becomes smaller than the bond lengths in typical analytes; the molecules then become "transparent" to the electrons and ionization efficiency decreases.		The ionization efficiency and production of fragment ions depends strongly on the chemistry of the analyte and the [[energy]] of the electrons. At low energies (around 20 [[Electronvolt\|eV]]), the interactions between the electrons and the analyte molecules do not transfer enough energy to cause ionization. At around 70 eV, the [[Louis-Victor de Broglie\|de Broglie]] [[wavelength]] of the electrons matches the length of typical bonds in organic molecules (about 0.14 nm) and energy transfer to organic analyte molecules is maximized, leading to the strongest possible ionization and fragmentation. Under these conditions, about 1 in 1000 analyte molecules in the source are ionized. At higher energies, the de Broglie wavelength of the electrons becomes smaller than the bond lengths in typical analytes; the molecules then become "transparent" to the electrons and ionization efficiency decreases.

-		+	==Notes==
		+	{{Reflist}}
	==References==		==References==
-	{{Reflist}}
-
-	==External links==
-
-	[http://webbook.nist.gov/cgi/cbook.cgi?ID=C108883&Units=SI&Mask=200#Mass-Spec NIST Chemistry WebBook]
-
-	==Bibliography==
	{{refbegin}}		{{refbegin}}
	*{{cite book \| author = Edmond de Hoffman \| coauthors = Vincent Stroobant \| title = Mass Spectrometry: Principles and Applications \| edition = 2nd ed. \| publisher = John Wiley and Sons \| year = 2001 \| isbn = 0-471-48566-7}}		*{{cite book \| author = Edmond de Hoffman \| coauthors = Vincent Stroobant \| title = Mass Spectrometry: Principles and Applications \| edition = 2nd ed. \| publisher = John Wiley and Sons \| year = 2001 \| isbn = 0-471-48566-7}}
Line 30:		Line 23:
	*{{cite book \|author= \|title=Electron impact ionization \|publisher=Springer-Verlag \|location=Berlin \|year=1985 \|pages= \|isbn=0-387-81778-6 \|oclc= \|doi= \|accessdate=}}		*{{cite book \|author= \|title=Electron impact ionization \|publisher=Springer-Verlag \|location=Berlin \|year=1985 \|pages= \|isbn=0-387-81778-6 \|oclc= \|doi= \|accessdate=}}
	{{refend}}		{{refend}}
		+
		+	==External links==
		+
		+	[http://webbook.nist.gov/cgi/cbook.cgi?ID=C108883&Units=SI&Mask=200#Mass-Spec NIST Chemistry WebBook]

	[[Category:Ion source]]		[[Category:Ion source]]

64.132.94.34: /* Flow splitting */

Mon, 05 Oct 2009 06:43:50 -0700

Flow splitting

← Previous revision		Revision as of 13:43, 5 October 2009
Line 18:		Line 18:
	===Flow splitting===		===Flow splitting===

-	When standard [[bore]] (4.6 mm) columns are used the flow is often split ~10:1. This can be beneficial by allowing the use of other techniques in tandem such as MS and UV. However splitting the flow to UV will decrease the sensitivity of spectrophotometric detectors. The Mass Spec on the other hand will give improved sensitivity at flow rates of 200 μL/min or less. This is because the analyte ions have to be vaporised (nebulized) in order to become charged.	+	When standard [[bore]] (4.6 mm) columns are used the flow is often split ~10:1. This can be beneficial by allowing the use of other techniques in tandem such as MS and UV. However splitting the flow to UV will decrease the sensitivity of spectrophotometric detectors. The Mass Spec on the other hand will give improved sensitivity at flow rates of 200 μL/min or less. This is because the analyte ions must be vaporised (nebulized) in order to become charged.

	==Mass spectrometry==		==Mass spectrometry==

Nick Y.: /* Manufacturers */ Please don't add links to non-existent articles

Fri, 02 Oct 2009 09:27:22 -0700

Manufacturers: Please don't add links to non-existent articles

← Previous revision		Revision as of 16:27, 2 October 2009
Line 106:		Line 106:
	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
-	* [[Tofwerk]]

	== See also ==		== See also ==

92.105.245.59: /* Manufacturers */

Fri, 02 Oct 2009 03:35:23 -0700

Manufacturers

← Previous revision		Revision as of 10:35, 2 October 2009
Line 106:		Line 106:
	* [[Jeol]]		* [[Jeol]]
	* [[LECO Corporation]]		* [[LECO Corporation]]
		+	* [[Tofwerk]]

	== See also ==		== See also ==

Until It Sleeps: Reverted edits by 201.16.211.4 to last revision by 208.242.58.125 (HG)

Fri, 18 Sep 2009 04:16:58 -0700

Reverted edits by 201.16.211.4 to last revision by 208.242.58.125 (HG)

← Previous revision		Revision as of 11:16, 18 September 2009
Line 14:		Line 14:
	==Liquid chromatography==		==Liquid chromatography==
	===Scale===		===Scale===
-	A major difference between traditional [[HPLC]] and the [[chromatography]] used in LC-MS is that in the latter case the scale is usually much smaller, both with respect to the internal diameter of the column and even more so with respect to flow rate since it scales as the square of the diameter. For a long time, 1 mm columns were typical for LC-MS work (as opposed to 4.6 mm for HPLC). More recently 300 µm and even 75 µm capillary columns have become more prevalent. At the low end of these column diameters the flow rates approach 100 nL/min and are generally used with [[nanospray]] sources.<ref>[http://dx.doi.org/10.1002/mas.1280130504 Capillary liquid chromatography/mass spectrometry, Kenneth B. Tomer, M. Arthur Moseley, Leesa J. Deterding, Carol E. Parker, Mass Spectrometry Reviews, Vol 13, 1994, pp 431-457]</ref> RONALDO BRILHA MUITO NU CURINTIA	+	A major difference between traditional [[HPLC]] and the [[chromatography]] used in LC-MS is that in the latter case the scale is usually much smaller, both with respect to the internal diameter of the column and even more so with respect to flow rate since it scales as the square of the diameter. For a long time, 1 mm columns were typical for LC-MS work (as opposed to 4.6 mm for HPLC). More recently 300 µm and even 75 µm capillary columns have become more prevalent. At the low end of these column diameters the flow rates approach 100 nL/min and are generally used with [[nanospray]] sources.<ref>[http://dx.doi.org/10.1002/mas.1280130504 Capillary liquid chromatography/mass spectrometry, Kenneth B. Tomer, M. Arthur Moseley, Leesa J. Deterding, Carol E. Parker, Mass Spectrometry Reviews, Vol 13, 1994, pp 431-457]</ref>

	===Flow splitting===		===Flow splitting===

201.16.211.4: /* Liquid chromatography */

Fri, 18 Sep 2009 04:16:53 -0700

Liquid chromatography

← Previous revision		Revision as of 11:16, 18 September 2009
Line 14:		Line 14:
	==Liquid chromatography==		==Liquid chromatography==
	===Scale===		===Scale===
-	A major difference between traditional [[HPLC]] and the [[chromatography]] used in LC-MS is that in the latter case the scale is usually much smaller, both with respect to the internal diameter of the column and even more so with respect to flow rate since it scales as the square of the diameter. For a long time, 1 mm columns were typical for LC-MS work (as opposed to 4.6 mm for HPLC). More recently 300 µm and even 75 µm capillary columns have become more prevalent. At the low end of these column diameters the flow rates approach 100 nL/min and are generally used with [[nanospray]] sources.<ref>[http://dx.doi.org/10.1002/mas.1280130504 Capillary liquid chromatography/mass spectrometry, Kenneth B. Tomer, M. Arthur Moseley, Leesa J. Deterding, Carol E. Parker, Mass Spectrometry Reviews, Vol 13, 1994, pp 431-457]</ref>	+	A major difference between traditional [[HPLC]] and the [[chromatography]] used in LC-MS is that in the latter case the scale is usually much smaller, both with respect to the internal diameter of the column and even more so with respect to flow rate since it scales as the square of the diameter. For a long time, 1 mm columns were typical for LC-MS work (as opposed to 4.6 mm for HPLC). More recently 300 µm and even 75 µm capillary columns have become more prevalent. At the low end of these column diameters the flow rates approach 100 nL/min and are generally used with [[nanospray]] sources.<ref>[http://dx.doi.org/10.1002/mas.1280130504 Capillary liquid chromatography/mass spectrometry, Kenneth B. Tomer, M. Arthur Moseley, Leesa J. Deterding, Carol E. Parker, Mass Spectrometry Reviews, Vol 13, 1994, pp 431-457]</ref> RONALDO BRILHA MUITO NU CURINTIA

	===Flow splitting===		===Flow splitting===

Rich Farmbrough: manually implement WP:pipe trick, Replaced: Science (journal) → Science, using AWB

Tue, 15 Sep 2009 06:38:40 -0700

manually implement WP:pipe trick, Replaced: Science (journal) → Science, using AWB

← Previous revision		Revision as of 13:38, 15 September 2009
Line 20:		Line 20:

	===The Taylor cone===		===The Taylor cone===
-	Voltages above the threshold draw the liquid into a cone. Sir [[Geoffrey Ingram Taylor]] described the theoretical shape of this cone based on the assumptions that (1) the surface of the cone is an equipotential surface and (2) the cone exists in a steady state equilibrium.<ref name=Taylor1964>{{cite journal \| author = Sir Geoffrey Taylor \| year = 1964 \| title = Disintegration of Water Droplets in an Electric Field \| journal = [[Proceedings_of_the_Royal_Society_A#Proceedings_of_the_Royal_Society_A\|Proc. Roy. Soc. London. Ser. A]] \| volume = 280 \| pages = 383 \| url = http://links.jstor.org/sici?sici=0080-4630%2819640728%29280%3A1382%3C383%3ADOWDIA%3E2.0.CO%3B2-Q&size=LARGE \| issue = 1382 \| doi = 10.1098/rspa.1964.0151}}</ref> To meet both of these criteria the electric field must have [[azimuth]]al symmetry and have <math>R^{1/2}\,</math> dependence to balance the surface tension and produce the cone. The solution to this problem is:	+	Voltages above the threshold draw the liquid into a cone. Sir [[Geoffrey Ingram Taylor]] described the theoretical shape of this cone based on the assumptions that (1) the surface of the cone is an equipotential surface and (2) the cone exists in a steady state equilibrium.<ref name="Taylor1964"/> To meet both of these criteria the electric field must have [[azimuth]]al symmetry and have <math>R^{1/2}\,</math> dependence to balance the surface tension and produce the cone. The solution to this problem is:

	:<math>V=V_0+AR^{1/2}P _{1/2} (\cos\theta _0)\,</math>		:<math>V=V_0+AR^{1/2}P _{1/2} (\cos\theta _0)\,</math>
Line 35:		Line 35:
	===Electrospray ionization===		===Electrospray ionization===
	:'' see also the main article on [[Electrospray ionization]]''		:'' see also the main article on [[Electrospray ionization]]''
-	Electrospray became widely used as ionization source for mass spectrometry after the Fenn group successfully demonstrated its use as ion source for the analysis of large biomolecules<ref>{{cite journal \| author = Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. \| title = Electrospray ionization for mass spectrometry of large biomolecules. \| journal = [[Science (journal)]] \| date = 2007 \| volume = 79 \| pages = 64–71 \| doi = 10.1126/science.2675315 \| pmid = 2675315}}</ref>.	+	Electrospray became widely used as ionization source for mass spectrometry after the Fenn group successfully demonstrated its use as ion source for the analysis of large biomolecules<ref>{{cite journal \| author = Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. \| title = Electrospray ionization for mass spectrometry of large biomolecules. \| journal = [[Science (journal)\|Science]] \| date = 2007 \| volume = 79 \| pages = 64–71 \| doi = 10.1126/science.2675315 \| pmid = 2675315}}</ref>.

	===Electrospinning===		===Electrospinning===

Kkmurray: Reverted 1 edit by 220.225.61.18 identified as vandalism to last revision by 72.234.210.227. (TW)

Wed, 09 Sep 2009 08:54:00 -0700

Reverted 1 edit by 220.225.61.18 identified as vandalism to last revision by 72.234.210.227. (TW)

← Previous revision		Revision as of 15:54, 9 September 2009
Line 78:		Line 78:

	===Security===		===Security===
-	A post-[[September 11]] development, [[explosive detection]] systems have become a part of all [[United States of America\|US]] [[airport]]s. These systems run on a host of technologies, many of them based on GC-MS. There are only three manufacturers certified by the [[Federal Aviation Administration\|FAA]] to provide these systems,{{Fact\|date=October 2007}} one of which is Thermo Detection (formerly Thermedics), which produces the [[Egis explosives detector\|EGIS]], a GC-MS-based line of explosives detectors. The other two manufacturers are Barringer Technologies, now owned by Smith's Detection Systems and Ion Track Instruments, part of General Electric Infrastructure Security Systems.no use	+	A post-[[September 11]] development, [[explosive detection]] systems have become a part of all [[United States of America\|US]] [[airport]]s. These systems run on a host of technologies, many of them based on GC-MS. There are only three manufacturers certified by the [[Federal Aviation Administration\|FAA]] to provide these systems,{{Fact\|date=October 2007}} one of which is Thermo Detection (formerly Thermedics), which produces the [[Egis explosives detector\|EGIS]], a GC-MS-based line of explosives detectors. The other two manufacturers are Barringer Technologies, now owned by Smith's Detection Systems and Ion Track Instruments, part of General Electric Infrastructure Security Systems.

	===Food, Beverage and Perfume Analysis===		===Food, Beverage and Perfume Analysis===

220.225.61.18: /* Security */

Wed, 09 Sep 2009 01:45:05 -0700

Security

← Previous revision		Revision as of 08:45, 9 September 2009
Line 78:		Line 78:

	===Security===		===Security===
-	A post-[[September 11]] development, [[explosive detection]] systems have become a part of all [[United States of America\|US]] [[airport]]s. These systems run on a host of technologies, many of them based on GC-MS. There are only three manufacturers certified by the [[Federal Aviation Administration\|FAA]] to provide these systems,{{Fact\|date=October 2007}} one of which is Thermo Detection (formerly Thermedics), which produces the [[Egis explosives detector\|EGIS]], a GC-MS-based line of explosives detectors. The other two manufacturers are Barringer Technologies, now owned by Smith's Detection Systems and Ion Track Instruments, part of General Electric Infrastructure Security Systems.	+	A post-[[September 11]] development, [[explosive detection]] systems have become a part of all [[United States of America\|US]] [[airport]]s. These systems run on a host of technologies, many of them based on GC-MS. There are only three manufacturers certified by the [[Federal Aviation Administration\|FAA]] to provide these systems,{{Fact\|date=October 2007}} one of which is Thermo Detection (formerly Thermedics), which produces the [[Egis explosives detector\|EGIS]], a GC-MS-based line of explosives detectors. The other two manufacturers are Barringer Technologies, now owned by Smith's Detection Systems and Ion Track Instruments, part of General Electric Infrastructure Security Systems.no use

	===Food, Beverage and Perfume Analysis===		===Food, Beverage and Perfume Analysis===

Orlady: avoid disambiguation page

Sun, 06 Sep 2009 07:31:33 -0700

avoid disambiguation page

← Previous revision		Revision as of 14:31, 6 September 2009
Line 24:		Line 24:

	==Manhattan Project==		==Manhattan Project==
-	A [[Calutron]] is a [[sector instrument\|sector mass spectrometer]] that was used for separating the [[isotopes]] of [[uranium]] developed by [[Ernest O. Lawrence]]<ref> {{cite web\|url=http://www.lbl.gov/Science-Articles/Research-Review/Magazine/1981/81fepi2.htm \|title=Lawrence and His Laborator \|accessdate=2007-09-03 \|year=1981 \|work=LBL Newsmagazine \|publisher=Lawrence Berkeley Lab }}</ref> during the [[Manhattan Project]] and was similar to the [[Cyclotron]] invented by Lawrence. Its name is a [[concatenation]] of Cal. U.-tron, in tribute to the [[University of California]], Lawrence's institution and the contractor of the [[Los Alamos National Laboratory\|Los Alamos]] laboratory.<ref name='OSTI ID: 20699216'> {{cite journal\|title=The Uranium Bomb, the Calutron, and the Space-Charge Problem\|journal=Physics Today\|date=2005-05-01\|first=William E.\|last=Parkins\|coauthors=\|volume=58\|issue=5\|pages=45–51\|doi= 10.1063/1.1995747}}\|url=http://masspec.scripps.edu/MSHistory/timelines/time_pdf/1947_ParkinsWE.pdf\|format=PDF\|accessdate=2007-09-01</ref> They were implemented for industrial scale [[uranium enrichment]] at the [[Oak Ridge, Tennessee]] [[Y-12]] plant established during the war and provided much of the uranium used for the "[[Little Boy]]" [[nuclear weapon]], which was dropped onto [[Hiroshima]] in [[1945]].	+	A [[Calutron]] is a [[sector instrument\|sector mass spectrometer]] that was used for separating the [[isotopes]] of [[uranium]] developed by [[Ernest O. Lawrence]]<ref> {{cite web\|url=http://www.lbl.gov/Science-Articles/Research-Review/Magazine/1981/81fepi2.htm \|title=Lawrence and His Laborator \|accessdate=2007-09-03 \|year=1981 \|work=LBL Newsmagazine \|publisher=Lawrence Berkeley Lab }}</ref> during the [[Manhattan Project]] and was similar to the [[Cyclotron]] invented by Lawrence. Its name is a [[concatenation]] of Cal. U.-tron, in tribute to the [[University of California]], Lawrence's institution and the contractor of the [[Los Alamos National Laboratory\|Los Alamos]] laboratory.<ref name='OSTI ID: 20699216'> {{cite journal\|title=The Uranium Bomb, the Calutron, and the Space-Charge Problem\|journal=Physics Today\|date=2005-05-01\|first=William E.\|last=Parkins\|coauthors=\|volume=58\|issue=5\|pages=45–51\|doi= 10.1063/1.1995747}}\|url=http://masspec.scripps.edu/MSHistory/timelines/time_pdf/1947_ParkinsWE.pdf\|format=PDF\|accessdate=2007-09-01</ref> They were implemented for industrial scale [[uranium enrichment]] at the [[Oak Ridge, Tennessee]] [[Y-12 National Security Complex\|Y-12 plant]] established during the war and provided much of the uranium used for the "[[Little Boy]]" [[nuclear weapon]], which was dropped onto [[Hiroshima]] in [[1945]].

	==Development of gas chromatography-mass spectrometry==		==Development of gas chromatography-mass spectrometry==

Nono64: /* See also */ Manufacturers

Sun, 06 Sep 2009 01:29:18 -0700

72.234.210.227: /* Full scan MS */

Wed, 02 Sep 2009 11:58:53 -0700

Full scan MS

← Previous revision		Revision as of 18:58, 2 September 2009
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	===Full scan MS===		===Full scan MS===
-	When collecting data in the full scan mode, a target range of mass fragments is determined and put into the instrument's method. An example of a typical broad range of mass fragments to monitor would be ''m/z'' 50 to ''m/z'' 400. The determination of what range to use is largely dictated by what one anticipates in being in the sample while being cognizant of the solvent and other possible interferences. A MS should not be set to look for mass fragments too low or else one may detect air (found as ''m/z'' 28 due to nitrogen), carbon dioxide (''m/z'' 44) or other possible interferences. Additionally if one is to use a large scan range then sensitivity of the instrument is decreased due to performing fewer scans per second since each scan will have to detect a wide range of mass fragments.	+	When collecting data in the full scan mode, a target range of mass fragments is determined and put into the instrument's method. An example of a typical broad range of mass fragments to monitor would be ''m/z'' 50 to ''m/z'' 400. The determination of what range to use is largely dictated by what one anticipates being in the sample while being cognizant of the solvent and other possible interferences. A MS should not be set to look for mass fragments too low or else one may detect air (found as ''m/z'' 28 due to nitrogen), carbon dioxide (''m/z'' 44) or other possible interferences. Additionally if one is to use a large scan range then sensitivity of the instrument is decreased due to performing fewer scans per second since each scan will have to detect a wide range of mass fragments.

	Full scan is useful in determining unknown compounds in a sample. It provides more information than SIM when it comes to confirming or resolving compounds in a sample. During instrument method development it may be common to first analyze test solutions in full scan mode to determine the retention time and the mass fragment fingerprint before moving to a SIM instrument method.		Full scan is useful in determining unknown compounds in a sample. It provides more information than SIM when it comes to confirming or resolving compounds in a sample. During instrument method development it may be common to first analyze test solutions in full scan mode to determine the retention time and the mass fragment fingerprint before moving to a SIM instrument method.

Dirac66: /* Discovery of isotopes */ Reworded sentence re Aston's identification of isotopes

Wed, 26 Aug 2009 13:23:13 -0700

Discovery of isotopes: Reworded sentence re Aston's identification of isotopes

← Previous revision		Revision as of 20:23, 26 August 2009
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	In 1913, as part of his exploration into the composition of [[canal rays]], [[J. J. Thomson]] channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on right), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22).<ref>JJ Thomson (1913), [http://web.lemoyne.edu/~giunta/canal.html ''Rays of positive electricity''], ''Proceedings of the Royal Society'', A 89, 1-20 — Discovery of neon isotopes</ref>		In 1913, as part of his exploration into the composition of [[canal rays]], [[J. J. Thomson]] channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on right), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22).<ref>JJ Thomson (1913), [http://web.lemoyne.edu/~giunta/canal.html ''Rays of positive electricity''], ''Proceedings of the Royal Society'', A 89, 1-20 — Discovery of neon isotopes</ref>

-	Thomson's student [[Francis William Aston]] continued the research at the Trinity College, building the first full functional mass spectrometer in 1919. He was able to identify the isotopes of [[chlorine]] with 35 an 37, [[bromine]] 79 and 81, [[krypton]] with 78, 80, 82, 83, 84 and 86, giving a proof of that the natural occurring elements are composed of a combination of isotopes. The use of electromagnetic focusing in [[mass spectrometry\|mass spectrograph]] which rapidly allowed him to identify no fewer than 212 of the 287 naturally occurring isotopes. In 1921 F. W. Aston became a fellow of the famous [[Royal Society]].	+	Thomson's student [[Francis William Aston]] continued the research at the Trinity College, building the first full functional mass spectrometer in 1919. He was able to identify isotopes of [[chlorine]] (35 and 37), [[bromine]] (79 and 81), and [[krypton]] (78, 80, 82, 83, 84 and 86), proving that these natural occurring elements are composed of a combination of isotopes. The use of electromagnetic focusing in [[mass spectrometry\|mass spectrograph]] which rapidly allowed him to identify no fewer than 212 of the 287 naturally occurring isotopes. In 1921 F. W. Aston became a fellow of the famous [[Royal Society]].

	His work on isotopes also led to his formulation of the [[Whole Number Rule]] which states that "the mass of the oxygen isotope being defined [as 16], all the other isotopes have masses that are very nearly whole numbers," a rule that was used extensively in the development of [[nuclear energy]]. The exact mass of many isotopes was measured leading to the result that hydrogen has a 1% higher mass than expected by the average mass of the other elements. Aston speculated about the subatomic energy and the use of it in 1936.		His work on isotopes also led to his formulation of the [[Whole Number Rule]] which states that "the mass of the oxygen isotope being defined [as 16], all the other isotopes have masses that are very nearly whole numbers," a rule that was used extensively in the development of [[nuclear energy]]. The exact mass of many isotopes was measured leading to the result that hydrogen has a 1% higher mass than expected by the average mass of the other elements. Aston speculated about the subatomic energy and the use of it in 1936.

Bordewolf at 19:22, 26 August 2009

Wed, 26 Aug 2009 12:22:52 -0700

← Previous revision		Revision as of 19:22, 26 August 2009
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	In 1913, as part of his exploration into the composition of [[canal rays]], [[J. J. Thomson]] channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on right), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22).<ref>JJ Thomson (1913), [http://web.lemoyne.edu/~giunta/canal.html ''Rays of positive electricity''], ''Proceedings of the Royal Society'', A 89, 1-20 — Discovery of neon isotopes</ref>		In 1913, as part of his exploration into the composition of [[canal rays]], [[J. J. Thomson]] channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on right), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22).<ref>JJ Thomson (1913), [http://web.lemoyne.edu/~giunta/canal.html ''Rays of positive electricity''], ''Proceedings of the Royal Society'', A 89, 1-20 — Discovery of neon isotopes</ref>

-	Thomson's student [[Francis William Aston]] continued the research at the Trinity College, building the first full functional mass spectrometer in 1919. He was able to identify the isotopes of [[chlorine]] with 35 an 37, [[bromine]] 79 and 78, [[krypton]] with 78, 80, 82, 83, 84 and 86, giving a proof of that the natural occurring elements are composed of a combination of isotopes. The use of electromagnetic focusing in [[mass spectrometry\|mass spectrograph]] which rapidly allowed him to identify no fewer than 212 of the 287 naturally occurring isotopes. In 1921 F. W. Aston became a fellow of the famous [[Royal Society]].	+	Thomson's student [[Francis William Aston]] continued the research at the Trinity College, building the first full functional mass spectrometer in 1919. He was able to identify the isotopes of [[chlorine]] with 35 an 37, [[bromine]] 79 and 81, [[krypton]] with 78, 80, 82, 83, 84 and 86, giving a proof of that the natural occurring elements are composed of a combination of isotopes. The use of electromagnetic focusing in [[mass spectrometry\|mass spectrograph]] which rapidly allowed him to identify no fewer than 212 of the 287 naturally occurring isotopes. In 1921 F. W. Aston became a fellow of the famous [[Royal Society]].

	His work on isotopes also led to his formulation of the [[Whole Number Rule]] which states that "the mass of the oxygen isotope being defined [as 16], all the other isotopes have masses that are very nearly whole numbers," a rule that was used extensively in the development of [[nuclear energy]]. The exact mass of many isotopes was measured leading to the result that hydrogen has a 1% higher mass than expected by the average mass of the other elements. Aston speculated about the subatomic energy and the use of it in 1936.		His work on isotopes also led to his formulation of the [[Whole Number Rule]] which states that "the mass of the oxygen isotope being defined [as 16], all the other isotopes have masses that are very nearly whole numbers," a rule that was used extensively in the development of [[nuclear energy]]. The exact mass of many isotopes was measured leading to the result that hydrogen has a 1% higher mass than expected by the average mass of the other elements. Aston speculated about the subatomic energy and the use of it in 1936.

Citation bot: Citation maintenance. [U]Formatted: title, pages, author, journal, volume, year. Unified citation types. You can use this bot yourself! Please report any bugs.

Sun, 23 Aug 2009 19:20:18 -0700

Citation maintenance. [U]Formatted: title, pages, author, journal, volume, year. Unified citation types. You can use this bot yourself! Please report any bugs.

← Previous revision		Revision as of 02:20, 24 August 2009
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	=== Aerosol laser desorption and ionization ===		=== Aerosol laser desorption and ionization ===
-	In Aerosol time-of-flight mass spectrometry, micrometer sized solid aerosol particles extracted from the atmosphere are simultaneously desorbed and ionized by a precisely timed laser pulse as they pass through the center of a time-of-flight ion extractor.<ref>{{Citation \| doi = 10.1016/0021-8502(94)00133-J }}</ref><ref>{{Citation \| doi = 10.1016/S0021-8502(00)90189-7 }}</ref>	+	In Aerosol time-of-flight mass spectrometry, micrometer sized solid aerosol particles extracted from the atmosphere are simultaneously desorbed and ionized by a precisely timed laser pulse as they pass through the center of a time-of-flight ion extractor.<ref>{{Cite journal \| doi = 10.1016/0021-8502(94)00133-J \| title = On-line chemical analysis of aerosols by rapid single-particle mass spectrometry \| year = 1995 \| author = Carson, P \| journal = Journal of Aerosol Science \| volume = 26 \| pages = 535 }}</ref><ref>{{Cite journal \| doi = 10.1016/S0021-8502(00)90189-7 \| title = Real time monitoring of size-resolved single particle chemistry during INDOEX-IFP 99 \| year = 2000 \| author = Guazzotti, S \| journal = Journal of Aerosol Science \| volume = 31 \| pages = 182 }}</ref>

	==Particle accelerators ==		==Particle accelerators ==

Kkmurray: /* Aerosol laser desorption and ionization */ add ref and template

Sun, 23 Aug 2009 19:19:01 -0700

Aerosol laser desorption and ionization: add ref and template

← Previous revision		Revision as of 02:19, 24 August 2009
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	=== Aerosol laser desorption and ionization ===		=== Aerosol laser desorption and ionization ===
-	In Aerosol time-of-flight mass spectrometry, micrometer sized solid aerosol particles extracted from the atmosphere are simultaneously desorbed and ionized by a precisely timed laser pulse as they pass through the center of a time-of-flight ion extractor. <ref>Gard, E.; Mayer, J.; Morrical, B.; Dienes, T.; Fergenson, D.; Prather, K.A. (1997) "Real-Time Analysis of Individual Atmospheric Aerosol Particles: Design and Performance of a Portable ATOFMS" Analytical Chemistry, 69 (20) 4083-4091</ref>	+	In Aerosol time-of-flight mass spectrometry, micrometer sized solid aerosol particles extracted from the atmosphere are simultaneously desorbed and ionized by a precisely timed laser pulse as they pass through the center of a time-of-flight ion extractor.<ref>{{Citation \| doi = 10.1016/0021-8502(94)00133-J }}</ref><ref>{{Citation \| doi = 10.1016/S0021-8502(00)90189-7 }}</ref>

	==Particle accelerators ==		==Particle accelerators ==

Td6 at 19:10, 23 August 2009

Sun, 23 Aug 2009 12:10:44 -0700

← Previous revision		Revision as of 19:10, 23 August 2009
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	{{main\|Matrix-assisted laser desorption electrospray ionization}}		{{main\|Matrix-assisted laser desorption electrospray ionization}}
	Matrix-assisted laser desorption electrospray ionization (MALDESI)<ref>Sampson JS, Hawkridge AM, Muddiman DC (2006). "Generation and detection of multiply-charged peptides and proteins by matrix-assisted laser desorption electrospray ionization (MALDESI) Fourier transform ion cyclotron resonance mass spectrometry". J. Am. Soc. Mass Spectrom. 17 (12): 1712–6. doi:10.1016/j.jasms.2006.08.003. PMID 16952462.</ref> is an atmospheric pressure ionization source for generation of multiply-charged ions. An ultraviolet or infrared laser is directed onto a solid or liquid sample containing the analyte of interest and matrix (UV = organic acid, IR = sacrificial analyte or water of hydration) desorbing neutral analyte molecules which are postionized by interaction with electrosprayed solvent droplets generating multiply charged ions.		Matrix-assisted laser desorption electrospray ionization (MALDESI)<ref>Sampson JS, Hawkridge AM, Muddiman DC (2006). "Generation and detection of multiply-charged peptides and proteins by matrix-assisted laser desorption electrospray ionization (MALDESI) Fourier transform ion cyclotron resonance mass spectrometry". J. Am. Soc. Mass Spectrom. 17 (12): 1712–6. doi:10.1016/j.jasms.2006.08.003. PMID 16952462.</ref> is an atmospheric pressure ionization source for generation of multiply-charged ions. An ultraviolet or infrared laser is directed onto a solid or liquid sample containing the analyte of interest and matrix (UV = organic acid, IR = sacrificial analyte or water of hydration) desorbing neutral analyte molecules which are postionized by interaction with electrosprayed solvent droplets generating multiply charged ions.
		+
		+	=== Aerosol laser desorption and ionization ===
		+	In Aerosol time-of-flight mass spectrometry, micrometer sized solid aerosol particles extracted from the atmosphere are simultaneously desorbed and ionized by a precisely timed laser pulse as they pass through the center of a time-of-flight ion extractor. <ref>Gard, E.; Mayer, J.; Morrical, B.; Dienes, T.; Fergenson, D.; Prather, K.A. (1997) "Real-Time Analysis of Individual Atmospheric Aerosol Particles: Design and Performance of a Portable ATOFMS" Analytical Chemistry, 69 (20) 4083-4091</ref>

	==Particle accelerators ==		==Particle accelerators ==

149.142.103.93: /* Split/Splitless GC-MS inlets */

Tue, 18 Aug 2009 15:26:57 -0700

Split/Splitless GC-MS inlets

← Previous revision		Revision as of 22:26, 18 August 2009
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	===Split/Splitless GC-MS inlets===		===Split/Splitless GC-MS inlets===
-	Samples are introduced to the column via an inlet. This inlet is typically injection through a septum. Once in the inlet, the heated chamber acts to volatilise (vapourise) the sample. In a split system, a constant flow of carrier gas moves through the inlet. A portion of the carrier gas flow acts to transport the sample into the column. Another portion of the carrier gas flow gets directed to purge the inlet of any sample following injection (septum purge). Yet another portion of the flow is directed through the split vent in a set ratio known as the split ratio. In a splitless system, the advantage is that a larger amount of sample is introduced to the column. However, a split system is preferred when the detector is sensitive to trace amounts of analyte and there is concern about overloading the column.	+	Samples are introduced to the column via an inlet. This inlet is typically injection through a septum. Once in the inlet, the heated chamber acts to volatilize the sample. In a split system, a constant flow of carrier gas moves through the inlet. A portion of the carrier gas flow acts to transport the sample into the column. Another portion of the carrier gas flow gets directed to purge the inlet of any sample following injection (septum purge). Yet another portion of the flow is directed through the split vent in a set ratio known as the split ratio. In a splitless system, the advantage is that a larger amount of sample is introduced to the column. However, a split system is preferred when the detector is sensitive to trace amounts of analyte and there is concern about overloading the column.

	===Purge and Trap GC-MS===		===Purge and Trap GC-MS===

Novangelis: Fix links and cleanup, Replaced: Saturn (planet)|Saturn → Saturn, using AWB

Mon, 03 Aug 2009 10:43:12 -0700

Fix links and cleanup, Replaced: Saturn (planet)|Saturn → Saturn, using AWB

← Previous revision		Revision as of 17:43, 3 August 2009
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	===Astrochemistry===		===Astrochemistry===
-	Several GC-MS have left earth. Two were brought to [[Mars]] by the [[Viking program]].<ref>[http://appel.nasa.gov/items/Viking_GCMS_case_07%2025%2006.pdf The Development of the Viking GCMS]</ref> [[Venera]] 11 and 12 and [[Pioneer Venus]] analysed the atmosphere of [[Venus]] with GC-MS.<ref>{{cite journal\|journal = Nature\|volume = 292\| pages = 610–613 \|year = 1981 \|doi = 10.1038/292610a0\|title =Chemical composition of the atmosphere of Venus\| author = V. A. Krasnopolsky, V. A. Parshev}}</ref> The [[Huygens probe]] of the [[Cassini-Huygens]] mission landed one GC-MS on [[Saturn (planet)\|Saturn's]] largest moon, [[Titan (moon)\|Titan]].<ref>{{cite journal \| title= The abundances of constituents of Titan’s atmosphere from the GCMS instrument on the Huygens probe \|author= H. B. Niemann, S. K. Atreya, S. J. Bauer, G. R. Carignan, J. E. Demick, R. L. Frost, D. Gautier, J. A. Haberman, D. N. Harpold, D. M. Hunten, G. Israel, J. I. Lunine, W. T. Kasprzak, T. C. Owen, M. Paulkovich, F. Raulin, E. Raaen, S. H. Way \|journal= [[Nature]] \|volume=438 \|pages=77–9–784 \|year=2005 \|doi=10.1038/nature04122 }}</ref> The material in the [[comet]] [[67P/Churyumov-Gerasimenko]] will be analysed by the [[Rosetta space probe\|Rosetta]] mission with a chiral GC-MS in 2014. <ref>{{cite journal \| title= COSAC onboard Rosetta: A bioastronomy experiment for the short-period comet 67P/Churyumov-Gerasimenko\|author= Goesmann F, Rosenbauer H, Roll R, Bohnhardt H	+	Several GC-MS have left earth. Two were brought to [[Mars]] by the [[Viking program]].<ref>[http://appel.nasa.gov/items/Viking_GCMS_case_07%2025%2006.pdf The Development of the Viking GCMS]</ref> [[Venera]] 11 and 12 and [[Pioneer Venus]] analysed the atmosphere of [[Venus]] with GC-MS.<ref>{{cite journal\|journal = Nature\|volume = 292\| pages = 610–613 \|year = 1981 \|doi = 10.1038/292610a0\|title =Chemical composition of the atmosphere of Venus\| author = V. A. Krasnopolsky, V. A. Parshev}}</ref> The [[Huygens probe]] of the [[Cassini-Huygens]] mission landed one GC-MS on [[Saturn's]] largest moon, [[Titan (moon)\|Titan]].<ref>{{cite journal \| title= The abundances of constituents of Titan’s atmosphere from the GCMS instrument on the Huygens probe \|author= H. B. Niemann, S. K. Atreya, S. J. Bauer, G. R. Carignan, J. E. Demick, R. L. Frost, D. Gautier, J. A. Haberman, D. N. Harpold, D. M. Hunten, G. Israel, J. I. Lunine, W. T. Kasprzak, T. C. Owen, M. Paulkovich, F. Raulin, E. Raaen, S. H. Way \|journal= [[Nature]] \|volume=438 \|pages=77–9–784 \|year=2005 \|doi=10.1038/nature04122 }}</ref> The material in the [[comet]] [[67P/Churyumov-Gerasimenko]] will be analysed by the [[Rosetta space probe\|Rosetta]] mission with a chiral GC-MS in 2014. <ref>{{cite journal \| title= COSAC onboard Rosetta: A bioastronomy experiment for the short-period comet 67P/Churyumov-Gerasimenko\|author= Goesmann F, Rosenbauer H, Roll R, Bohnhardt H
	\|journal= Astrobiology\|volume= 5\|issue=5\|pages= 622–631\|year= 2005\|doi=10.1089/ast.2005.5.622}}</ref>		\|journal= Astrobiology\|volume= 5\|issue=5\|pages= 622–631\|year= 2005\|doi=10.1089/ast.2005.5.622}}</ref>

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	*{{cite book \|author=Adlard, E. R.; Handley, Alan J. \|title=Gas chromatographic techniques and applications \|publisher=Sheffield Academic \|location=London \|year=2001 \|pages= \|isbn=0-8493-0521-7 \|oclc= \|doi=}}		*{{cite book \|author=Adlard, E. R.; Handley, Alan J. \|title=Gas chromatographic techniques and applications \|publisher=Sheffield Academic \|location=London \|year=2001 \|pages= \|isbn=0-8493-0521-7 \|oclc= \|doi=}}
	*{{cite book \|author=Eugene F. Barry; Grob, Robert Lee \|title=Modern practice of gas chromatography \|publisher=Wiley-Interscience \|location=New York \|year=2004 \|pages= \|isbn=0-471-22983-0 \|oclc= \|doi=}}		*{{cite book \|author=Eugene F. Barry; Grob, Robert Lee \|title=Modern practice of gas chromatography \|publisher=Wiley-Interscience \|location=New York \|year=2004 \|pages= \|isbn=0-471-22983-0 \|oclc= \|doi=}}
-	* Eiceman, G.A. (2000). Gas Chromatography. In R.A. Meyers (Ed.), ''Encyclopedia of Analytical Chemistry: Applications, Theory, and Instrumentation'', pp. 10627. Chichester: Wiley. ISBN 0-471-97670-9	+	* Eiceman, G.A. (2000). Gas Chromatography. In R.A. Meyers (Ed.), ''Encyclopedia of Analytical Chemistry: Applications, Theory, and Instrumentation'', pp. 10627. Chichester: Wiley. ISBN 0-471-97670-9
-	* Giannelli, Paul C. and Imwinkelried, Edward J. (1999). Drug Identification: Gas Chromatography. In ''Scientific Evidence'' '''2''', pp. 362. Charlottesville: Lexis Law Publishing. ISBN 0-327-04985-5.	+	* Giannelli, Paul C. and Imwinkelried, Edward J. (1999). Drug Identification: Gas Chromatography. In ''Scientific Evidence'' '''2''', pp. 362. Charlottesville: Lexis Law Publishing. ISBN 0-327-04985-5.
	*{{cite book \|author=McEwen, Charles N.; Kitson, Fulton G.; Larsen, Barbara Seliger \|title=Gas chromatography and mass spectrometry: a practical guide \|publisher=Academic Press \|location=Boston \|year=1996 \|pages= \|isbn=0-12-483385-3 \|oclc= \|doi=}}		*{{cite book \|author=McEwen, Charles N.; Kitson, Fulton G.; Larsen, Barbara Seliger \|title=Gas chromatography and mass spectrometry: a practical guide \|publisher=Academic Press \|location=Boston \|year=1996 \|pages= \|isbn=0-12-483385-3 \|oclc= \|doi=}}
	*{{cite book \|author=McMaster, Christopher; McMaster, Marvin C. \|title=GC/MS: a practical user's guide \|publisher=Wiley \|location=New York \|year=1998 \|pages= \|isbn=0-471-24826-6 \|oclc= \|doi=}}		*{{cite book \|author=McMaster, Christopher; McMaster, Marvin C. \|title=GC/MS: a practical user's guide \|publisher=Wiley \|location=New York \|year=1998 \|pages= \|isbn=0-471-24826-6 \|oclc= \|doi=}}
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	{{Mass spectrometry}}		{{Mass spectrometry}}

		+	{{DEFAULTSORT:Gas Chromatography-Mass Spectrometry}}
	[[Category:Mass spectrometry]]		[[Category:Mass spectrometry]]
	[[Category:Chromatography]]		[[Category:Chromatography]]

J.delanoy: Reverted edits by 202.150.111.103 to last revision by Kkmurray (HG)

Sun, 12 Jul 2009 19:06:33 -0700

Reverted edits by 202.150.111.103 to last revision by Kkmurray (HG)

← Previous revision		Revision as of 02:06, 13 July 2009
Line 1:		Line 1:
-	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for volatile [[organic chemistry\|organic]] molecules in Soviet Russia.	+	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for volatile [[organic chemistry\|organic]] molecules.

	==Principle of operation==		==Principle of operation==

202.150.111.103 at 02:06, 13 July 2009

Sun, 12 Jul 2009 19:06:16 -0700

← Previous revision		Revision as of 02:06, 13 July 2009
Line 1:		Line 1:
-	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for volatile [[organic chemistry\|organic]] molecules.	+	'''Electron ionization''' ('''EI''', formerly known as '''electron impact''') is an ionization method in which energetic [[electron]]s interact with gas phase atoms or molecules to produce [[ion]]s.<ref>{{GoldBookRef\|title=electron ionization\|file=E01999}}</ref> This technique is widely used in [[mass spectrometry]], particularly for volatile [[organic chemistry\|organic]] molecules in Soviet Russia.

	==Principle of operation==		==Principle of operation==

208.242.58.125: /* Pharmacokinetics */

Thu, 09 Jul 2009 09:48:13 -0700

Pharmacokinetics

← Previous revision		Revision as of 16:48, 9 July 2009
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	LC-MS is very commonly used in [[pharmacokinetic]] studies of pharmaceuticals. These studies give information about how quickly a drug will be cleared from the hepatic blood flow, and organs of the body. MS is used for this due to high sensitivity and exceptional specificity compared to UV (as long as the analyte can be suitably ionised), and short analysis time.		LC-MS is very commonly used in [[pharmacokinetic]] studies of pharmaceuticals. These studies give information about how quickly a drug will be cleared from the hepatic blood flow, and organs of the body. MS is used for this due to high sensitivity and exceptional specificity compared to UV (as long as the analyte can be suitably ionised), and short analysis time.

-	The major advantage MS has is the use of tandem MS-MS. You can program the detector to select certain ions to fragment. The process is essentially a selection technique, but is in fact more complex. The measured quantity is the sum of molecule fragments chosen by the operator. As long as there are no interferences or ion suppression, the LC separation can be quite quick. It is common now to have analysis times of 1 minute or less by MS-MS detection, compared to over 10 mins with UV detection.<ref>Increasing Speed and Throughput When Using HPLC-MS/MS Systems for Drug Metabolism and Pharmacokinetic Screening, Y. Hsieh and W.A. Korfmacher, Current Drug Metabolism Volume 7, Number 5, 2006, Pp. 479-489</ref><ref>Covey TR, Lee ED, Henion JD. 1986. High-speed liquid chromatography/tandem mass spectrometry for the determination of drugs in biological samples. Anal Chem 58:2453-2460.</ref><ref>Thermospray liquid chromatography/mass spectrometry determination of drugs and their metabolites in biological fluids. Covey TR et al. Anal Chem. 1985 Feb;57(2):474-81</ref>	+	The major advantage MS has is the use of tandem MS-MS. The detector may be programmed to select certain ions to fragment. The process is essentially a selection technique, but is in fact more complex. The measured quantity is the sum of molecule fragments chosen by the operator. As long as there are no interferences or ion suppression, the LC separation can be quite quick. It is common now to have analysis times of 1 minute or less by MS-MS detection, compared to over 10 mins with UV detection.<ref>Increasing Speed and Throughput When Using HPLC-MS/MS Systems for Drug Metabolism and Pharmacokinetic Screening, Y. Hsieh and W.A. Korfmacher, Current Drug Metabolism Volume 7, Number 5, 2006, Pp. 479-489</ref><ref>Covey TR, Lee ED, Henion JD. 1986. High-speed liquid chromatography/tandem mass spectrometry for the determination of drugs in biological samples. Anal Chem 58:2453-2460.</ref><ref>Thermospray liquid chromatography/mass spectrometry determination of drugs and their metabolites in biological fluids. Covey TR et al. Anal Chem. 1985 Feb;57(2):474-81</ref>

	===Proteomics===		===Proteomics===

208.254.130.235: /* Pharmacokinetics */

Thu, 09 Jul 2009 09:46:23 -0700

Pharmacokinetics

← Previous revision		Revision as of 16:46, 9 July 2009
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	==Applications==		==Applications==
	===Pharmacokinetics===		===Pharmacokinetics===
-	LC-MS is very commonly used in [[pharmacokinetic]] studies of pharmaceuticals. These studies tell us how quickly a drug will be cleared from the hepatic blood flow, and organs of the body. MS is used for this due to high sensitivity and exceptional specificity compared to UV (as long as the analyte can be suitably ionised), and short analysis time.	+	LC-MS is very commonly used in [[pharmacokinetic]] studies of pharmaceuticals. These studies give information about how quickly a drug will be cleared from the hepatic blood flow, and organs of the body. MS is used for this due to high sensitivity and exceptional specificity compared to UV (as long as the analyte can be suitably ionised), and short analysis time.

	The major advantage MS has is the use of tandem MS-MS. You can program the detector to select certain ions to fragment. The process is essentially a selection technique, but is in fact more complex. The measured quantity is the sum of molecule fragments chosen by the operator. As long as there are no interferences or ion suppression, the LC separation can be quite quick. It is common now to have analysis times of 1 minute or less by MS-MS detection, compared to over 10 mins with UV detection.<ref>Increasing Speed and Throughput When Using HPLC-MS/MS Systems for Drug Metabolism and Pharmacokinetic Screening, Y. Hsieh and W.A. Korfmacher, Current Drug Metabolism Volume 7, Number 5, 2006, Pp. 479-489</ref><ref>Covey TR, Lee ED, Henion JD. 1986. High-speed liquid chromatography/tandem mass spectrometry for the determination of drugs in biological samples. Anal Chem 58:2453-2460.</ref><ref>Thermospray liquid chromatography/mass spectrometry determination of drugs and their metabolites in biological fluids. Covey TR et al. Anal Chem. 1985 Feb;57(2):474-81</ref>		The major advantage MS has is the use of tandem MS-MS. You can program the detector to select certain ions to fragment. The process is essentially a selection technique, but is in fact more complex. The measured quantity is the sum of molecule fragments chosen by the operator. As long as there are no interferences or ion suppression, the LC separation can be quite quick. It is common now to have analysis times of 1 minute or less by MS-MS detection, compared to over 10 mins with UV detection.<ref>Increasing Speed and Throughput When Using HPLC-MS/MS Systems for Drug Metabolism and Pharmacokinetic Screening, Y. Hsieh and W.A. Korfmacher, Current Drug Metabolism Volume 7, Number 5, 2006, Pp. 479-489</ref><ref>Covey TR, Lee ED, Henion JD. 1986. High-speed liquid chromatography/tandem mass spectrometry for the determination of drugs in biological samples. Anal Chem 58:2453-2460.</ref><ref>Thermospray liquid chromatography/mass spectrometry determination of drugs and their metabolites in biological fluids. Covey TR et al. Anal Chem. 1985 Feb;57(2):474-81</ref>

Kkmurray: /* Selective Ion Monitoring */ change selective to selected per IUPAC

Mon, 06 Jul 2009 11:18:27 -0700

Selective Ion Monitoring: change selective to selected per IUPAC

← Previous revision		Revision as of 18:18, 6 July 2009
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	Full scan is useful in determining unknown compounds in a sample. It provides more information than SIM when it comes to confirming or resolving compounds in a sample. During instrument method development it may be common to first analyze test solutions in full scan mode to determine the retention time and the mass fragment fingerprint before moving to a SIM instrument method.		Full scan is useful in determining unknown compounds in a sample. It provides more information than SIM when it comes to confirming or resolving compounds in a sample. During instrument method development it may be common to first analyze test solutions in full scan mode to determine the retention time and the mass fragment fingerprint before moving to a SIM instrument method.

-	===Selective Ion Monitoring===	+	===Selected ion monitoring===
-	In Selective Ion Monitoring (SIM) certain ion fragments are entered into the instrument method and only those mass fragments are detected by the mass spectrometer. The advantages of SIM are that the detection limit is lower since the instrument is only looking at a small number of fragments (e.g. three fragments) during each scan. More scans can take place each second. Since only a few mass fragments of interest are being monitored, [[matrix interference]]s are typically lower. To additionally confirm the likelihood of a potentially positive result, it is relatively important to be sure that the ion ratios of the various mass fragments are comparable to a known reference standard.	+	In selected ion monitoring (SIM) certain ion fragments are entered into the instrument method and only those mass fragments are detected by the mass spectrometer. The advantages of SIM are that the detection limit is lower since the instrument is only looking at a small number of fragments (e.g. three fragments) during each scan. More scans can take place each second. Since only a few mass fragments of interest are being monitored, [[matrix interference]]s are typically lower. To additionally confirm the likelihood of a potentially positive result, it is relatively important to be sure that the ion ratios of the various mass fragments are comparable to a known reference standard.

	===Types of Ionization===		===Types of Ionization===

Citation bot: Citation maintenance. [U]Added: journal, volume, pages. Formatted: author, title, year. Unified citation types. You can use this bot yourself! Please report any bugs.

Fri, 03 Jul 2009 13:25:02 -0700

Citation maintenance. [U]Added: journal, volume, pages. Formatted: author, title, year. Unified citation types. You can use this bot yourself! Please report any bugs.

← Previous revision		Revision as of 20:25, 3 July 2009
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	==History==		==History==
-	The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s by Roland Gohlke and Fred McLafferty.<ref>{{Citation \| doi = 10.1021/ac50164a024}}</ref><ref>{{Citation \| doi =10.1016/1044-0305(93)85001-E }}</ref> These sensitive devices were bulky, fragile, and originally limited to laboratory settings. The development of affordable and [[miniaturized]] [[computer]]s has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1996 the top-of-the-line high-speed GC-MS units completed analysis of fire accelerants in less than 90 seconds, whereas first-generation GC/MS would have required at least 16 minutes.{{Fact\|date=June 2007}} This has led to their widespread adoption in a number of fields.	+	The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s by Roland Gohlke and Fred McLafferty.<ref>{{Cite journal \| doi = 10.1021/ac50164a024 \| title = Time-of-Flight Mass Spectrometry and Gas-Liquid Partition Chromatography \| year = 1959 \| author = Gohlke, R. S. \| journal = Analytical Chemistry \| volume = 31 \| pages = 535}}</ref><ref>{{Cite journal \| doi =10.1016/1044-0305(93)85001-E \| title =Early gas chromatography/mass spectrometry \| year =1993 \| author =Gohlke, R \| journal =Journal of the American Society for Mass Spectrometry \| volume =4 \| pages =367 }}</ref> These sensitive devices were bulky, fragile, and originally limited to laboratory settings. The development of affordable and [[miniaturized]] [[computer]]s has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1996 the top-of-the-line high-speed GC-MS units completed analysis of fire accelerants in less than 90 seconds, whereas first-generation GC/MS would have required at least 16 minutes.{{Fact\|date=June 2007}} This has led to their widespread adoption in a number of fields.

	==Instrumentation==		==Instrumentation==

Kkmurray: put doi in refs

Fri, 03 Jul 2009 13:24:18 -0700

put doi in refs

← Previous revision		Revision as of 20:24, 3 July 2009
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	==History==		==History==
-	The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s by Roland Gohlke and Fred McLafferty.<ref>Gohlke, R. S., [http://masspec.scripps.edu/MSHistory/timelines/time_pdf/1956_Gohlke.pdf Time-of-flight mass spectrometry and gas-liquid partition chromatography]. ''Anal. Chem.'' '''1959''', ''31'', 535-41</ref><ref>Gohlke, R. S.; McLafferty, F. W., [http://dx.doi.org/10.1016/1044-0305(93)85001-E Early gas chromatography/mass spectrometry.]'' J. Am. Soc. Mass Spectrom.'' '''1993''', ''4'', (5), 367-371.</ref> These sensitive devices were bulky, fragile, and originally limited to laboratory settings. The development of affordable and [[miniaturized]] [[computer]]s has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1996 the top-of-the-line high-speed GC-MS units completed analysis of fire accelerants in less than 90 seconds, whereas first-generation GC/MS would have required at least 16 minutes.{{Fact\|date=June 2007}} This has led to their widespread adoption in a number of fields.	+	The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s by Roland Gohlke and Fred McLafferty.<ref>{{Citation \| doi = 10.1021/ac50164a024}}</ref><ref>{{Citation \| doi =10.1016/1044-0305(93)85001-E }}</ref> These sensitive devices were bulky, fragile, and originally limited to laboratory settings. The development of affordable and [[miniaturized]] [[computer]]s has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1996 the top-of-the-line high-speed GC-MS units completed analysis of fire accelerants in less than 90 seconds, whereas first-generation GC/MS would have required at least 16 minutes.{{Fact\|date=June 2007}} This has led to their widespread adoption in a number of fields.

	==Instrumentation==		==Instrumentation==

Kkmurray: Reverted 1 edit by 58.27.167.241 identified as vandalism to last revision by 71.42.186.162. (TW)

Thu, 02 Jul 2009 12:05:30 -0700

Reverted 1 edit by 58.27.167.241 identified as vandalism to last revision by 71.42.186.162. (TW)

← Previous revision		Revision as of 19:05, 2 July 2009
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	== Theory ==		== Theory ==
		+	[[Image:Stephens TOF.gif\|right\|300 px\|thumb\|Figure from William E. Stephens 1952 TOF patent.<ref>{{Cite patent\|US\|2847576}}</ref>]]
	The [[potential energy]] of a charged particle in an electric field is related to the charge of the particle and to the strength of the electric field:		The [[potential energy]] of a charged particle in an electric field is related to the charge of the particle and to the strength of the electric field:

The Original Wildbear: rm extraneous word

Sun, 28 Jun 2009 21:16:12 -0700

rm extraneous word

← Previous revision		Revision as of 04:16, 29 June 2009
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	{{main\|Electrospray ionization}}		{{main\|Electrospray ionization}}

-	In electrospray ionization, a [[liquid]] is pushed through a very small, charged and usually [[metal]], [[capillary]].<ref>{{cite journal \| doi = 10.1002/mas.1280090103 \| author = Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. \| title = Electrospray Ionization-Principles and Practice \| journal = [[Mass Spectrometry Reviews]] \| date = 1990 \| volume = 9 \| issue = 1 \| pages = 37–70}}</ref> This liquid contains the substance to be studied, the [[analyte]], dissolved in a large amount of [[solvent]], which is usually much more [[Volatility (chemistry)\|volatile]] than the analyte. Volatile [[acid]]s, [[base (chemistry)\|bases]] or [[buffer (chemistry)\|buffers]] are often added to this solution too. The analyte exists as an [[ion]] in solution either in its anion or cation form. Because like [[electric charge\|charges]] repel, the liquid pushes itself out of the capillary and forms an [[Particulate\|aerosol]], a mist of small droplets about 10 [[micro\|μm]] across. The aerosol is at least partially produced by a process involving the formation of a [[Taylor cone]] and a jet from the tip of this cone. An uncharged carrier gas such as [[nitrogen]] is sometimes used to help [[nebulizer\|nebulize]] the liquid and to help [[evaporate]] the neutral solvent in the droplets. As the solvent evaporates, the analyte molecules are forced closer together, repel each other and break up the droplets. This process is called Coulombic fission because it is driven by repulsive [[Coulombic force]]s between charged molecules. The process repeats until the analyte is free of solvent and is a bare [[ion]]. The ions observed may are created by the addition of a [[proton]] (a hydrogen ion) and denoted <math>[M+H]^+</math>, or of another [[cation]] such as [[sodium]] ion, <math>[M+Na]^+</math>, or the removal of a proton, <math>[M-H]^-</math>. Multiply-charged ions such as <math>[M+2H]^{2+}</math> are often observed. For large [[macromolecules]], there can be many charge states, occurring with different frequencies; the charge can be as great as <math>[M+25H]^{25+}</math>, for example.	+	In electrospray ionization, a [[liquid]] is pushed through a very small, charged and usually [[metal]], [[capillary]].<ref>{{cite journal \| doi = 10.1002/mas.1280090103 \| author = Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. \| title = Electrospray Ionization-Principles and Practice \| journal = [[Mass Spectrometry Reviews]] \| date = 1990 \| volume = 9 \| issue = 1 \| pages = 37–70}}</ref> This liquid contains the substance to be studied, the [[analyte]], dissolved in a large amount of [[solvent]], which is usually much more [[Volatility (chemistry)\|volatile]] than the analyte. Volatile [[acid]]s, [[base (chemistry)\|bases]] or [[buffer (chemistry)\|buffers]] are often added to this solution too. The analyte exists as an [[ion]] in solution either in its anion or cation form. Because like [[electric charge\|charges]] repel, the liquid pushes itself out of the capillary and forms an [[Particulate\|aerosol]], a mist of small droplets about 10 [[micro\|μm]] across. The aerosol is at least partially produced by a process involving the formation of a [[Taylor cone]] and a jet from the tip of this cone. An uncharged carrier gas such as [[nitrogen]] is sometimes used to help [[nebulizer\|nebulize]] the liquid and to help [[evaporate]] the neutral solvent in the droplets. As the solvent evaporates, the analyte molecules are forced closer together, repel each other and break up the droplets. This process is called Coulombic fission because it is driven by repulsive [[Coulombic force]]s between charged molecules. The process repeats until the analyte is free of solvent and is a bare [[ion]]. The ions observed are created by the addition of a [[proton]] (a hydrogen ion) and denoted <math>[M+H]^+</math>, or of another [[cation]] such as [[sodium]] ion, <math>[M+Na]^+</math>, or the removal of a proton, <math>[M-H]^-</math>. Multiply-charged ions such as <math>[M+2H]^{2+}</math> are often observed. For large [[macromolecules]], there can be many charge states, occurring with different frequencies; the charge can be as great as <math>[M+25H]^{25+}</math>, for example.

	=== Desorption electrospray ionization ===		=== Desorption electrospray ionization ===

← Previous revision		Revision as of 05:42, 5 November 2009
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	[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]		[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]
-	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).	+	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).

	The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.		The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.

← Previous revision		Revision as of 05:41, 5 November 2009
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	[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]		[[Image:MALDITOF.jpg\|thumb\|right\|200 px\|MALDI TOF mass spectrometer]]
-	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).	+	'''Matrix-assisted laser desorption/ionization (MALDI)''' is a soft [[ionization]] technique used in [[mass spectrometry]], allowing the analysis of [[biomolecule]]s ([[biopolymer]]s such as [[proteins]], [[peptides]] and [[sugars]]) and large [[organic chemistry\|organic]] [[molecules]] (such as [[polymers]], [[dendrimers]] and other [[macromolecules]]), which tend to be fragile and fragment when ionized by more conventional ionization methods. It is most similar in character to [[electrospray ionization]] both in relative softness and the ions produced (although it causes many fewer multiply charged ions).

	The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.		The ionization is triggered by a [[laser\|laser beam]] (normally a [[nitrogen laser]]). A matrix is used to protect the biomolecule from being destroyed by direct [[laser]] beam and to facilitate vaporization and ionization.

← Previous revision		Revision as of 03:05, 23 October 2009
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	\| [[ferulic acid]]\|\| [[acetonitrile]], water, [[propanol]] \|\| 337, 355, 266 \|\| proteins		\| [[ferulic acid]]\|\| [[acetonitrile]], water, [[propanol]] \|\| 337, 355, 266 \|\| proteins
	\|-		\|-
-	! [[Alpha-cyano-4-hydroxycinnamic acid\|α-cyano-4-hydroxycinnamic acid]]<ref>{{cite journal \|title=-α-Cyano-4-hydroxycinnamic acid as a matrix for matrix-assisted laser desorption mass spectrometry \|journal=Org. Mass Spectrom. \|volume=27 \|issue= \|pages=156–8 \|year=1992 \|doi=10.1002/oms.1210270217 \|author=Beavis, R. C. }}</ref>	+	! [[Alpha-cyano-4-hydroxycinnamic acid\|α-cyano-4-hydroxycinnamic acid]]<ref>{{cite journal \|title=-α-Cyano-4-hydroxycinnamic acid as a matrix for matrix-assisted laser desorption mass spectrometry \|journal=Org. Mass Spectrom. \|volume=27 \|issue= \|pages=156–8 \|year=1992 \|doi=10.1002/oms.1210270217 \|author=Beavis, R. C. \|first2=T. \|first3=B. T. }}</ref>
	\| CHCA \|\| [[acetonitrile]], water, [[ethanol]], acetone \|\| 337, 355 \|\|peptides, lipids, nucleotides		\| CHCA \|\| [[acetonitrile]], water, [[ethanol]], acetone \|\| 337, 355 \|\|peptides, lipids, nucleotides
	\|-		\|-
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	The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:		The identity of suitable matrix compounds is determined to some extent by trial and error, but they are based on some specific molecular design considerations:
	* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.		* They are of a fairly low molecular weight (to allow facile vaporization), but are large enough (with a low enough vapor pressure) not to evaporate during sample preparation or while standing in the spectrometer.
-	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993){{Citation \| doi = 10.1021/ac00070a007}}</ref>.	+	* They are often acidic, therefore act as a proton source to encourage ionization of the analyte. Basic matrices have also been reported <ref>(Fitzgerald et al., Anal. Chem. 65:3204-3211,1993){{Cite journal \| doi = 10.1021/ac00070a007 \| title = Basic matrixes for the matrix-assisted laser desorption/ionization mass spectrometry of proteins and oligonucleotides \| year = 1993 \| last1 = Fitzgerald \| first1 = Michael C. \| first2 = Gary R. \| first3 = Lloyd M. \| journal = Analytical Chemistry \| volume = 65 \| pages = 3204}}</ref>.
-	* They have a strong optical absorption in either the UV or IR range, <ref>Zenobi and Knochenmuss Mass Spectrometry Reviews 17: 337-366, 1998 {{Citation \| doi = 10.1002/(SICI)1098-2787(1998)17:5<337::AID-MAS2>3.0.CO;2-S}}</ref> so that they rapidly and efficiently absorb the laser irradiation.	+	* They have a strong optical absorption in either the UV or IR range, <ref>Zenobi and Knochenmuss Mass Spectrometry Reviews 17: 337-366, 1998 {{Cite journal \| doi = 10.1002/(SICI)1098-2787(1998)17:5<337::AID-MAS2>3.0.CO;2-S}}</ref> so that they rapidly and efficiently absorb the laser irradiation.
	* They are functionalized with polar groups, allowing their use in aqueous solutions.		* They are functionalized with polar groups, allowing their use in aqueous solutions.

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	===In polymer chemistry===		===In polymer chemistry===
-	In polymer chemistry MALDI can be used to determine the [[molar mass distribution]].<ref name="isbn3-540-44259-6">{{cite book \|author=W. Schrepp; Harald Pasch \|title=Maldi-Tof Mass Spectrometry of Synthetic Polymers (Springer Laboratory) \|publisher=Springer-Verlag \|location=Berlin \|year=2003 \|pages= \|isbn=3-540-44259-6 \|oclc= 51330276\|doi= \|accessdate=}}</ref> Polymers with [[polydispersity]] greater than 1.2 are difficult to characterize with MALDI due to the signal intensity discrimination against higher mass oligomers.<ref name=Nielen1997>{{Cite journal \| last = Nielen \| first = Michel W. F. \| year = 1997 \| title = Characterization of polydisperse synthetic polymers by size-exclusion chromatography/matrix-assisted laser desorption/ionization time-of-flight mass spectrometry \| journal = Rapid Communications in Mass Spectrometry \| volume = 11 \| pages = 1194 \| doi = 10.1002/(SICI)1097-0231(199707)11:11<1194::AID-RCM935>3.0.CO;2-L }}</ref><ref name="pmid9666717">{{cite journal \|author=Wu KJ, Odom RW \|title=Characterizing synthetic polymers by MALDI MS \|journal=Analytical chemistry \|volume=70 \|issue=13 \|pages=456A–461A \|year=1998 \|month=July \|pmid=9666717 \|doi= \|url=}}</ref><ref name=Schriemer1997>{{Cite journal \| last = Schriemer \| first = D.C. \| year = 1997 \| title = Mass Discrimination in the Analysis of Polydisperse Polymers by MALDI Time-of-Flight Mass Spectrometry. 2. Instrumental Issues \| journal = Analytical Chemistry \| volume = 69 \| pages = 4176 \| doi = 10.1021/ac9707794 }}</ref>	+	In polymer chemistry MALDI can be used to determine the [[molar mass distribution]].<ref name="isbn3-540-44259-6">{{cite book \|author=W. Schrepp; Harald Pasch \|title=Maldi-Tof Mass Spectrometry of Synthetic Polymers (Springer Laboratory) \|publisher=Springer-Verlag \|location=Berlin \|year=2003 \|pages= \|isbn=3-540-44259-6 \|oclc= 51330276\|doi= \|accessdate=}}</ref> Polymers with [[polydispersity]] greater than 1.2 are difficult to characterize with MALDI due to the signal intensity discrimination against higher mass oligomers.<ref name=Nielen1997>{{Cite journal \| last = Nielen \| first = Michel W. F. \| year = 1997 \| title = Characterization of polydisperse synthetic polymers by size-exclusion chromatography/matrix-assisted laser desorption/ionization time-of-flight mass spectrometry \| journal = Rapid Communications in Mass Spectrometry \| volume = 11 \| pages = 1194 \| doi = 10.1002/(SICI)1097-0231(199707)11:11<1194::AID-RCM935>3.0.CO;2-L }}</ref><ref name="pmid9666717">{{cite journal \|author=Wu KJ, Odom RW \|title=Characterizing synthetic polymers by MALDI MS \|journal=Analytical chemistry \|volume=70 \|issue=13 \|pages=456A–461A \|year=1998 \|month=July \|pmid=9666717 \|doi= \|url=}}</ref><ref name=Schriemer1997>{{Cite journal \| last = Schriemer \| first = D.C. \| year = 1997 \| title = Mass Discrimination in the Analysis of Polydisperse Polymers by MALDI Time-of-Flight Mass Spectrometry. 2. Instrumental Issues \| journal = Analytical Chemistry \| volume = 69 \| pages = 4176 \| doi = 10.1021/ac9707794 \| first2 = Liang }}</ref>

	== Reproducibility and performance==		== Reproducibility and performance==
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	{{refbegin}}		{{refbegin}}
	*{{cite journal \|author=Hillenkamp F, Karas M, Beavis RC, Chait BT \|title=Matrix-assisted laser desorption/ionization mass spectrometry of biopolymers \|journal=Anal. Chem. \|volume=63 \|issue=24 \|pages=1193A–1203A \|year=1991 \|pmid=1789447 \|doi=10.1021/ac00024a002}}		*{{cite journal \|author=Hillenkamp F, Karas M, Beavis RC, Chait BT \|title=Matrix-assisted laser desorption/ionization mass spectrometry of biopolymers \|journal=Anal. Chem. \|volume=63 \|issue=24 \|pages=1193A–1203A \|year=1991 \|pmid=1789447 \|doi=10.1021/ac00024a002}}
-	*{{cite journal \|author=Ragoussis J, Elvidge GP, Kaur K, Colella S \|title=Matrix-assisted laser desorption/ionisation, time-of-flight mass spectrometry in genomics research \|journal=PLoS Genet. \|volume=2 \|issue=7 \|pages=e100 \|year=2006 \|pmid=16895448 \|doi=10.1371/journal.pgen.0020100}}	+	*{{cite journal \|author=Ragoussis J, Elvidge GP, Kaur K, Colella S \|title=Matrix-assisted laser desorption/ionisation, time-of-flight mass spectrometry in genomics research \|journal=PLoS Genet. \|volume=2 \|issue=7 \|pages=e100 \|year=2006 \|pmid=16895448 \|doi=10.1371/journal.pgen.0020100 \|pmc=1523240}}
	*{{cite journal \|author=Hardouin J \|title=Protein sequence information by matrix-assisted laser desorption/ionization in-source decay mass spectrometry \|journal=Mass spectrometry reviews \|volume=26 \|issue=5 \|pages=672–82 \|year=2007 \|pmid=17492750 \|doi=10.1002/mas.20142}}		*{{cite journal \|author=Hardouin J \|title=Protein sequence information by matrix-assisted laser desorption/ionization in-source decay mass spectrometry \|journal=Mass spectrometry reviews \|volume=26 \|issue=5 \|pages=672–82 \|year=2007 \|pmid=17492750 \|doi=10.1002/mas.20142}}
	*{{cite book \|author=Jasna Peter-Katalinic; Franz Hillenkamp \|title=MALDI MS: A Practical Guide to Instrumentation, Methods and Applications \|publisher=Wiley-VCH \|location=Weinheim \|year= 2007\|pages= \|isbn=3-527-31440-7 \|oclc= 180943017\|doi=}}		*{{cite book \|author=Jasna Peter-Katalinic; Franz Hillenkamp \|title=MALDI MS: A Practical Guide to Instrumentation, Methods and Applications \|publisher=Wiley-VCH \|location=Weinheim \|year= 2007\|pages= \|isbn=3-527-31440-7 \|oclc= 180943017\|doi=}}

← Previous revision		Revision as of 08:29, 6 September 2009
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	[[Atom probe]] tomography also takes advantage of TOF mass spectrometry.		[[Atom probe]] tomography also takes advantage of TOF mass spectrometry.
		+
		+	== Manufacturers==
		+	* [[Jeol]]
		+	* [[LECO Corporation]]

	== See also ==		== See also ==