Levels of selected polychlorinated biphenyl congeners in total diet samples from Aragón, Spain.

Six congeners of polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, and 180) were investigated in 281 samples of different meals of the average diet consumed in Aragon, northeast Spain. PCB residues were extracted with organic solvents according to the techniques recommended by the U.S. Food and Drug Administration and the Netherlands' Ministry of Welfare, Health, and Cultural Affairs; the residues were cleaned up by gel permeation chromatography. Quantitation of analytes was carried out by capillary gas-liquid chromatography using electron capture detector. The identity of the peaks was confirmed by mass spectrometry. PCB residues were found only in fish meals (50% positive samples) with a mean level of 96.3 ng/g on a lipid basis. Congeners detected in fish meals were 138, 153, and 180, with mean values of 117.0, 122.3, and 36.2 ng/g on a lipid basis, respectively.