Pyrolysis of amino acids compared to ion fragments formation

Pyrolysis of a-amino acids has significant implications in the interpretation of the results of peptide and protein pyrolysis. Amino acid thermal decomposition takes place through four main fragmentation pathways as shown below  

The amines may react further with the elimination of ammonia  

diketopiperazines may undergo further pyrolysis decomposing as follows  

In a mass spectrometer, the ions are generated by El from amino acids through one of the following schemes  

The result of this path of ion formation is equivalent to the amine formation by amino acid decarboxylation. 

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Pyrolysis of amino acids compared to ion fragments formation. 

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