The identification of cyclic nucleotides from living systems using collision-induced dissociation of ions generated by fast atom bombardment mass spectrometry

Extracts derived from rat liver and Phaseolus leaves are shown, by collision-induced dissociation of [MH]+ ions generated by fast atom bombardment mass spectrometry, to contain cytidine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate respectively, and not the 2',3'-cyclic isomers. Interference peaks, expected to be common to all mass-analysed ion kinetic energy spectra of ions generated by the fast atom bombardment process from glycerol-based matrices are identified. It is shown that unequivocal identification of cytidine 3',5'-cyclic monophosphate can be made at the microgram level. Attempts to derive a quantitative procedure based on using different cyclic nucleotides as internal standards were unsuccessful due to the poor solubility of these compounds in the matrix system.