Determination of Non- and Mono-ortho-Polychlorinated Biphenyls in Background Ambient Air

Abstract

An analytical procedure has been developed for the isomer-specific determination of polychlorinated biphenyls in background ambient air. The methodology uses Carbosphere activated carbon and isotope dilution HRGC/MS for the isolation and analysis of the toxic fraction of PCBs in the presence of all other, less or nontoxic congeners. This toxic fraction includes the non-ortho- and mono-ortho-PCBs, which recently were assigned by a WHO/IPCS expert group on toxicity as being the most toxic congeners. The method provides quantification limits ranging from 0.01 to 0.08 pg/m3. Mean atmospheric levels for the sum of these congeners varied between 3.0 and 5.0 pg/m3 with some events with higher concentrations. PCB 126 typically present at 0.03 pg/m3 was found to contribute 77% of the total toxic equivalent values in air samples.