Method for the Determination of Three Toxic Non-Orthochlorine Substituted Coplanar PCBs in Environmental Samples at Part-per-Trillion Levels

摘要

A method has been devised combining alkali digestion, carbon chromatography and high-resolution gas chromatography for the determination of 3,3#x2032;,4,4#x2032;-tetra, 3,3#x2032;,4,4#x2032;,5-penta, and 3,3#x2032;,4,4#x2032;,5,5#x2032;-hexachlorobiphenyl, the biologically active congeners of PCBs and approximate isostereomers of 2,3,7,8-TCDD. This method permits determinations of parts-per-trillion levels of these toxic residues in biological samples. Interference both from biogenic and from xenobiotic substances was reduced to extremely low levels. Using this method, 13.5 ng of 3,3#x2032;,4,4#x2032;-tetrachlorobiphenyl/g, 0.89 ng of 3,3#x2032;,4,4#x2032;,5-pentachlorobiphenyl/g and 0.64 ng of 3,3#x2032;,4,4,5,5#x2032;-hexachlorobiphenyl/g were detected on wet weight basis in the blubber of a finless porpoise. To our knowledge this is the first report on the three toxic non-ortho chlorine substituted PCB residues detected in a higher mammal in the wilderness.