ABSTRACT
Mass spectrometry has been extensively used in the detection and confirmation of polychlorinated biphenyl's (PCB) in the environment, and in addition the electron impact-induced fragmentation reactions of pure isomeric chlorobiphenyls have also been examined. In order to understand the relatively complex mass spectra of commercial Aroclor mixtures, the mass spectra of the isomeric chlorobiphenyls and several di-, tri-, tetra-, hexa-, and octachlorobiphenyl isomers have been studied in detail. In addition, spectra of penta-, hepta-, nona-, and decachlorobiphenyl have also been reported. The fragmentation pattern of the PCB isomers featured successive expulsion of Cl atoms with the odd-electron species being more abundant than the even-electron ions. The detection of PCB's in the environment has been confirmed by mass spectrometry in a number of studies in which the appropriate GC peaks have been shown to be composed of chlorinated biphenyl isomers(s).
