DISSOCIATIVE ELECTRON-ATTACHMENT NEGATIVE-ION MASS-SPECTROMETRY - A CHLORINE-SPECIFIC DETECTOR FOR GAS-CHROMATOGRAPHY

This work describes the application of negative ion chemical ionizatio n, optimized for dissociative electron attachment (DEA), to location o f unknown trace chlorinated compounds in complex gas chromatograms by selected ion recording (SLR) of m/z 35 and 37. The DEA-SIR technique i s compared with other GC detectors, including the electron capture det ector, electrolytic conductivity detector, the atomic emission detecto r and the chemical reaction interface mass spectrometry method, with r espect to selectivity for chlorine, sensitivity, linear dynamic range, and general robustness and ease of use. When applied to quantitative analysis of target analytes such as polychlorobiphenyls, the DEA-SIR m ethod has potential problems arising from the possibility of suppressi on effects due to abundant co-eluting components, and possible allevia ting measures are discussed. In addition to these practical investigat ions, literature information on the fundamental physical and chemical phenomena underlying the DEA process is summarized in order to guide f uture work on extension to other compound types and on general improve ments to the technique. Crown Copyright (C) 1997 Published by Elsevier Science B.V.