GAS-CHROMATOGRAPHY DETERMINATION OF POLYCHLORINATED-BIPHENYLS IN POWDERED AND LIQUID SOYBEAN MILKS

A method previously validated for the analysis of individual congeners of polychlorinated biphenyls (PCBs) in soybean infant formulas is now used to determine PCB levels in dairy-like soybean derivatives, inclu ding liquid and powdered soybean milks. Some differences were found am ong PCB levels and profiles calculated from die different liquid and p owdered soybean milks investigated when compared to previously reporte d for soybean infant formulas, and those most common in dairy-products from Spain and from other countries. PCB levels detected in liquid so ybean milks were lower than those found in powdered soybean milks. Lev els reported for these two dairy-like derivatives were lower than thos e detected in soybean infant formulas. The most apparent difference am ong soybean derivatives and cow's milk was that individual PCB levels detected in the former were lower than those reported for the latter, except for congeners 126 and, specifically, 77, which showed the oppos ite trend. This feature was common to all soybean products investigate d including infant formulas, powdered and liquid soybean milks. (C) 19 98 Elsevier Science B.V. All rights reserved.