Analysis of alkenes by copper ion chemical ionization gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry

Abstract

A novel chemical ionization/fast atom bombardment (CI/FAB) source was used to analyse alkenes by chemical ionization mass spectrometry (CI-MS) using copper ions as the ionizing agent. The Cu(+)-CI mass spectra showed abundant pseudomolecular adduct ions [alkene-Cu](+) and characteristic fragment ions. Mass-analysed ion kinetic energy spectroscopy was used to study the product ions resulting from the decomposition of adduct ions and to eliminate background interferences derived from the copper ions. The major fragmentations permitted the localization of double bonds and minor fragments allowed the differentiation of alkene isomers. The CI/FAB source was coupled to a gas chromatograph and simple and complex mixtures of octene isomers were analysed by gas chromatography (GC)/Cu(+)-CI-MS and GC/Cu(+)-CI-MS/MS. Copyright 1999 John Wiley & Sons, Ltd.