CHARGE-REMOTE FRAGMENTATION OF FATTY-ACID ANIONS IN 400 EV COLLISIONSWITH XENON ATOMS

In an effort to assess the performance of a new commercial hybrid magn etic sector-time-of-flight tandem mass spectrometer for the structural analysis of fatty acids, collision-induced dissociation spectra of st earic, oleic, linoleic and arachidonic acids have been recorded. Pseud omolecular [M - H](-) parent ions were generated by electrospray ioniz ation, accelerated to 4 keV, selected by the double focussing sectors of the tandem mass spectrometer, decelerated to 400 eV and focused int o a collision cell containing xenon. The resulting fragment ions were mass analysed by an orthogonal time-of-flight analyser The CID spectra showed charge-remote fragmentation patterns, from which the location of double bonds could be determined.