ANALYSIS OF POLYCYCLIC AROMATIC-HYDROCARBONS BY ION-TRAP TANDEM MASS-SPECTROMETRY

An ion-trap mass spectrometer with a wave board and tandem mass spectr ometry software was used to analyze gas chromatographically separated polycyclic aromatic hydrocarbons (PAHs) by using collision-induced dis sociation (CID). The nonresonant (multiple collision) mode was used to determine the conditions for CID ionization of 18 PAHs. Unlike in ele ctron impact (EI) analysis, the relative abundances of progeny ions of isomers were statistically different (using Student's t-test) in CID analysis, thus making isomer identification by CID possible. For compa rison, CID and EI were applied to the analysis of used motor oil. CID analysis was shown to be more sensitive than EI analysis of the used m otor oil. Precision at the 10-ppb level for EI and CID showed relative standard deviations of 5.2 and 7.7%, respectively. (C) 1997 American Society for Mass Spectrometry