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| Jean-Fran???ɂ??܂Ć?ɬ????ɂİ?Ǭ???ois GAL???ɂ??Ǩ??ɂ?ɬ????ɂİ?Ǭ?Ǩ
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| 02-28-2004 10:07 AM ET (US)
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| "Mass/charge ratio Add your comment on this item
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| (m/z) ratio."
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| Sorry to insist ... Sparkman would say "mass-to-charge ratio".
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| ----
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| == m/z is wrong ==
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| let's get rid of the ''m/z''. It is conceptually wrong.
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| I made a new proposal.
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| {{Sugdef|mass/charge|The mass/charge ratio is a physical property that is measured by [[Mass Spectrometer | mass spectrometers]].
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| The symbol for the physical quantity mass/charge is ''[[M/q|m/q]]''. The former ''[[m/z]]'' is based on a [[Talk:Mass/Charge Ratio (Th, never use Da, no units?. An ion of m/z or an ion at m/z?)|missconception]] and should no longer be used.
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| The SI unit of the physical quantity ''m/q'' is kilogram/coulomb ('''kg/C''').
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| In [[Mass Spectrometry | mass spectrometry]] it is more common to use the [[Atomic Mass Unit]] '''u''' and the [http://www.iupac.org/goldbook/A00504.pdf atomic unit] for charge '''e''' which is equal to the [http://www.iupac.org/goldbook/E02032.pdf elementary charge].
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| This means the unit for mass/charge is:
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| : [''m/q''] = '''u'''/'''e'''
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| For simplicity, '''u''' is better called [[Dalton]] ('''Da''') and '''e''' is called [[Millikan]] ('''Mi''').
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| '''u'''/'''e''' is sometimes called [[Thomson]] ('''Th''').
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| Therefore
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| : [''m/q''] = '''u'''/'''e''' = '''Da'''/'''Mi''' = '''Th'''
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| Hence, a [[Mass Spectrum | mass spectrum]] x-axis should be labeled as either of the below:
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| * ''m/q'' ('''u'''/'''e''')
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| * ''m/q'' ('''Da'''/'''Mi''')
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| * ''m/q'' ('''Th''')
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| '''References'''
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| :[http://www.iupac.org/goldbook/Q04982.pdf gold book: quantity]
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| :[http://www.iupac.org/goldbook/P04666.pdf gold book: physical quantity]
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| :[http://www.iupac.org/goldbook/V06593.pdf gold book: value of a quantity]
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| }}
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| --[[User:Ionworker|Ionworker]] 06:55, 15 Jan 2005 (CST)
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