Analytical response of single polychlorinated biphenyls analysed by selected ion monitoring

The analytical response of 45 single polychlorinated biphenyls to electron impact spectrometry was measured by monitoring their positive molecular ion intensity. The results showed little variability in response within the isomer groups with the same number of chlorine atoms, and the average response is proposed as a basis for quantitation of the polychlorinated biphenyl level for the corresponding degree of chlorination. The possibility of distinguishing the level of each polychlorinated biphenyl group by a method as specific and sensitive as gas chromatography combined with mass spectrometry could be very useful, especially in toxicology studies. Preliminary data obtained from application of the technique in studies of marine organisms are presented.