A Report on an Intercomparison Study of the Determination of Chlorinated Biphenyl (PCB) Isomers in Fish Oil

Five laboratories, employing capillary column gas chromatography, determined the levels of many chlorinated biphenyl isomers (PCB isomers) in Aroclor 1254 and in herring oil and the same oil spiked with Aroclor 1254. This study showed that the results were characterized by a large interlaboratory variance, and that very few of the same isomers were being analyzed by all participants. The results also suggests that misidentification of isomers may be occurring