Total polychlorinated biphenyl quantification by rapid dechlorination under mild conditions

The congeners of polychlorinated biphenyls (PCBs) and many of those of the chlorinated pesticides have many physical and chemical similarities. These features present a problem during chromatographic analyses of these species in the form of coeluted peaks. Reductive dechlorination of these organochlorides greatly simplifies the resulting chromatograms and allows for the quantification of total PCB content by resolving the resultant biphenyl peak by gas chromatography with flame ionization detection. The authors of this article found that they could easily accomplish rapid dechlorination of PCBs, toxaphene, chlordane, and dichlorodiphenyltrichloroethane (DDT) at room temperature and atmospheric pressure using palladium-magnesium bimetallic particles. Using this method, they obtained a 580-ppb estimated detection limit for total PCB content in the presence of the interfering species.