Abstract
The presence of aromatic hydrocarbons in pesticide-grade hexanes affects the elution patterns of polychlorinated biphenyls (PCB) and chlorinated hydrocarbon pesticides from silicic acid columns. Several batches of silicic acid Silicar® (Mallinckrodt) were contaminated with 0.031–0.163 mcg/g of PCB expressed as Aroclor® 1254. Chlorinated naphthalenes accompany PCB on silicic acid chromatography and their presence can be detected from an absorption maximum at 306 nm, A1% 1cm = 329. PCB of the Aroclor® 1254 type were detected in American eel (Anguilla rostrata), herring (Clupea harengus), and Atlantic salmon (Salmo salar) in concentrations of 0.63–0.75, 0.32–0.54, and 0.45 mcg/g wet weight, respectively. Commercial fish oil contained 3.55 mcg/g of PCB.