A novel fragmentation process in the fast‐atom bombardment/tandem mass spectra of peptides cationized with Na+, determining the identity of the C‐terminal amino acid

Abstract The metastable ion spectra of the [M + Na] + ions generated by fast‐atom bombardment of sodium chloride containing oligopeptide samples are shown to produce an intense sequence ion from which the identity of the C‐terminal amino acid can be readily established.