Immunoassay screening method for polychlorinated biphenyls in transformer oil

We described here the results of measuring the PCB levels in eleven hundred transformer oil samples using an immunoassay screening method. Five hundred samples out of the total were remeasured using a GPC/GC/ECD method. A comparison of these results on ROC (receiver operating characteristic) plots showed that the immunoassay provides a useful screening method. In the case that the regulatory concentration of the total PCB was set at 0.5 mg/kg, the Most Suitable cutoff concentration for the immunoassay for screening was calculated to be at 0.4 mg/kg with false negative and false positive rates of zero and seven percent, respectively.