Mass Spectrometry – Focus on Proteomics

Introductory Example:  mass spectrum of water •   Electron Impact (EI)   -   Hard (fragments) / 1000 Da    H2O  + fast electron    [H2O]+   +  2 electrons            + fragments ([OH]+, O+, H+)

Fragmentation pattern

[H2O]+     18 [OH]+         17 O+         16 H+              1

(“fingerprint”)

Mass-to-charge ratio