Quantitative determination of PCBs in soil and water by a magnetic particle-based immunoassay

A competitive enzyme immunoassay for the quantification of polychlorinated biphenyls (PCBs) in soil and water was developed utilizing amine-terminated superparamagnetic particles as the solid phase. Aroclor 1254 was covalently attached to a bovine serum albumin carrier, and the resulting PCB-protein conjugate was used to immunize rabbits and to produce polyclonal antibodies with reactivity to a broad range of PCBs. Specificity studies indicate that the polyclonal antibody can detect Aroclors 1016, 1232, 1242, 1248, 1254, 1260, 1262, and 1268. The immunoassay has a estimated detection limit of 0.2 ppb (ng/mL) in water and 0.5 ppm (mg/kg) in soil based on Aroclor 1254. The assay compares favorably to GC method 8080 results when soil (r = 0.960) or water samples are evaluated (r = 0.909). The typical within assay % CV is less than 9% in water samples, and recovery studies averaged 99% in water and 85% in soil using a 1-min extraction. This immunochemical method provides quantitative field or laboratory screening results for characterizing and delineating PCB-contaminated sites.