CU-IONIZATION FOR ANALYSIS OF HYDROCARBONS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY( CHEMICAL)

The use of copper ions for chemical ionization (CI) coupled with gas c hromatography/mass spectrometry (GC/MS) of hydrocarbons is reported. C u+-CI was performed in a high-pressure, fast atom bombardment ion sour ce coupled with both a gas chromatograph and a mass spectrometer. The suitability of the Cu+-CI method is illustrated by the analysis of pur e alkylbenzenes, alkylthiophenes, octenes, and by the analysis of a li ght mixture of aromatic hydrocarbons. The Cu+-CI/GC mass spectra displ ay an abundant [M+Cu-63](+) ion, together with fragmentations, that ar e of structural interest. The detection limit for isobutylbenzene, tak en as model compound, is 100 times lower than that for electron ioniza tion. (C) 1998 American Society for Mass Spectrometry.