Widespread occurrence of the pesticide toxaphene in Canadian east coast marine fish.

Chromatographic and chemical confirmatory evidence is presented for the presence of residues of toxaphene, a polychlorinated camphene pesticide, in herring (Clupea harengus harengus) and cod (Gadus morhua) from widely-separated areas of the Canadian east coast. Toxaphene residues were not detected in a sample of deep-sea scallops (Placopecten magellanicus). Toxaphene was determined by capillary gas chromatography following a combination of chromatography and fuming nitric-concentrated sulfuric acid cleanup, a procedure which greatly simplified the capillary gas chromatograms and eliminated many co-extractives. Concentrations in the fish tissues ranged from 0.4 to 1.1 micrograms/g on a net weight basis and from 2.4 to 12 micrograms/g on a fat weight bais. These data indicate widespread contamination of the marine environment by chlorinated camphenes.