Mass Spectrometry Amino acid fragmentation pattern

Mass spectral fragmentation patterns of alkyl and phenyl hydantoins have been investigated by means of labeling techniques (28—30), and similar studies have also been carried out for thiohydantoins (31,32). In all cases, breakdown of the hydantoin ring occurs by a-ftssion at C-4 with concomitant loss of carbon monoxide and an isocyanate molecule. In the case of aryl derivatives, the ease of formation of Ar—NCO is related to the electronic properties of the aryl ring substituents (33). Mass spectrometry has been used for identification of the phenylthiohydantoin derivatives formed from amino acids during peptide sequence determination by the Edman method (34). 

The mass spectrum of a molecule provides information about its structure. At the frontier of mass spectrometry today, scientists are elucidating the sequences of amino acids in proteins and the structures of complex carbohydrates by their fragmentation patterns. In this section, we touch on some of the simplest information available from mass spectrometry. 

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