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Chemistry LibreTexts

Mass-to-Charge Ratio

[ "article:topic", "authorname:ggunawardena" ]
  • Page ID
    40653
  • In mass spectroscopy, the mass-to-charge ratio (symbols: m/z, m/e) of a cation is equal to the mass of the cation divided by its charge.

     

     

    Since the charge of cation formed in the mass spectrometer is almost always +1, the mass-to-charge ratio of a cation is usually equal to the mass of the cation.

     

     

    The mass of the molecular ion is equal to the molecular weight of the compound.  Thus, the mass-to-charge ratio of the molecular ion is equal to the molecular weight of the compound.