Direct competitive ELISA for the determination of polychlorinated biphenyls in soil samples

A direct competitive ELISA for determination of polychlorinated biphenyls (PCB) in soil samples was described. The standard calibration curve based on Delor 103 (Aroclor 1242) was constructed in the dynamic range of 10-1000 mug L-1 and a detection limit of 5.0-12.9 mug L-1 (or 0.5-1.29 mug g(-1) soil) was achieved. When spiked soil samples were extracted with methanol recoveries were 90.6-106.3%. The effect of methanol and DMSO on assay signal and sensitivity was established. Eight PCB-contaminated soil samples were analyzed by ELISA and gas chromatography (GC). The ELISA results from Soxhlet extraction were in a good agreement with those of GC (correlation coefficient 0.9866; n=8). Except for one soil sample the results from ELISA with methanol extraction were not significantly different from those from GC.