Detection of polychlorinated biphenyls in fats.

A thin layer chromatographic method of separation and detection of polychlorinated biphenyls (PCB) was developed, using petroleum ether as developing solvent and 1% orthotolidine in acetone as spray reagent. As low as 0.1 mug of the PCB (1254, 1242, 1260 and 1268) could be extracted by petroleum ether and cleaned up by the sulphuric acid method. DDT, alpha, gamma, beta and delta HCH did not interfere in the TLC separation and detection of PCB from oils and fats. As low as 0.4 ppm could be detected from oils and fats by using this method.