TRIPLE QUADRUPOLE TANDEM MASS-SPECTROMETRIC STUDY OF THE 3-PICOLINYL ESTERS OF FATTY-ACIDS

Low-energy collision-induced dissociation of some representative 3-picolinyl esters of fatty acids were investigated. The daughter-ion spectra of the precursor ions showed similar features to the electron impact num spectra, but the low intensity of the parent-ion signal did not allow reliable deductions. The parent-ion spectra of some fragments that retain the pyridine derivatizing group contain structurally useful information, and are suitable for analytical application. These spectra also contain fragment ions which may account for an alternative pathway to that currently proposed for the generation of certain fragment ions within the ion source. Both pathways were investigated in this tandem mass spectrometric study. Isomerization and decomposition of distonic fragment ions through loss of alkenes yield species with a shorter alkyl chain, which are particularly stable when they contain allylic radicals.