A simple ultraviolet method for discriminating between polychlorobiphenyls and organochloride pesticides coeluting under gas chromatography with electron-capture detection

Certain congeners of Aroclor 1260 coelute with o,p′- or p,p′-DDT under gas chromatography with electron-capture detection. We describe a simple ulraviolet irradiation method that allows qualitative and quantitative analyses of mixtures of these organochlorides in complex matrices. Detection limits are 0.20 and 0.22 μg/kg dry mass for Aroclor 1260 and the two DDTs, respectively. The method is applied to six replicate pork liver samples, for which recoveries ranged from 72 to 90%.