Amino-catalyzed fragmentation characteristics of polyamides containing N-methylpyrrole and N-methylimidazole by electrospray negative ionization mass spectrometry.

Different negative fragmentations of synthesized polyamides containing N-methylpyrrole and N-methylimidazole were analyzed by electrospray ionization tandem mass spectrometry with low-energy collision-induced dissociation. An interesting rearrangement derived from amino catalysis of N-methylimidazole was observed. The observation is useful for the study of the correlations between the sequences of polyamides and their mass fragmentation pathways.