MASS-SPECTROMETRY OF DERIVATIVES OF ISOMERIC ALLENIC FATTY-ACIDS

The electron impact mass spectra have been obtained for isomeric C-14 and C18 allenic fatty acids in the form of the methyl and picolinyl ester derivatives. When the allene moiety was in positions 3 to 9, the mass spectra of the methyl esters gave spectra with diagnostic ions that appeared to be formed by beta cleavage on the distal side of the molecule; otherwise hydrocarbon ions were dominant. With the picolinyl ester derivatives, distinctive fragmentations beta to the allene moiety on each side were observed for each isomer.