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| == [[Orange Book]] Entry ==
| | #REDIRECT [[Mass/charge ratio]] |
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| ''m/z'' ratio.
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| == [[Gold Book]] Entry ==
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| The abbreviation ''m/z'' is used to denote the dimensionless quantity formed by dividing the mass number of an ion by its charge number. It has long been called the [[mass-to-charge ratio]] although m is not the ionic mass nor is z a multiple or the elementary (electronic) charge, e. The abbreviation m/e is, therefore, not recommended. Thus, for example, for the ion C<sub>7</sub>H<sub>7</sub><sup>2+</sup>, ''m/z'' equals 45.5..
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| == Proposed New Entry ==
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| 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''. The former [[''m/z'']] is based on a 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]] it is more common to use the [[Atomic Mass Unit]] '''u''' and the [http://www.example.com atomic unit] for charge '''e'''.
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| This means the unit for mass/charge is:
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| : [''m/q''] = '''u'''/'''e'''
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| '''u''' is sometimes called [[Dalton]] ('''Da'''). '''u'''/'''e''' is sometimes called [[Thomson]] ('''Th'''). 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'''/'''e''')
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| * ''m/q'' ('''Th''')
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