44G-5 |
ELISA analysis of PCBs in fish tissue |
J. A. LASRADO1, C. R. Santerre1, J. L. Zajieck2, D. E. Tillitt2, and D. C. Deardorff3. (1) Foods and Nutrition, Purdue University, 1264 Stone Hall, West Lafayette, IN 47906, (2) U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201, (3) Strategic Diagnostic Inc., King of Prussia, PA 19406 Polychlorinated biphenyls (PCBs) have been banned in the US since 1977. Currently across the US, 679 fish consumption advisories have been issued by agencies in 35 States due to the presence of PCBs in wild fish. Most PCB analysis is done using an FDA standard method, which is time consuming (days to weeks), expensive ($250 per assay) and produces excessive waste (4L solvent waste per assay). Therefore, a rapid technique for detecting PCBs in fish tissue would help in the development of consumption advisories. To develop and validate a procedure for the extraction and cleanup of PCBs in fish tissue prior to ELISA and to demonstrate differences in binding to antibodies for the three mixtures. Spiked ground catfish tissue (1 g), mixed with anhydrous Na2SO4, was placed on a column of sulfuric acid-silica gel and extracted with hexane. The extracts were evaporated, diluted with 50% (v/v) methanol in the ELISA diluent and analyzed by ELISA. Since consumption advisories set a threshold at 2 ppm PCB to totally eliminate contaminated fish from the diet, standard curves were developed from 0.05 to 5 ppm. The curves were linear from 0.05-0.5 ppm and 0.5-5.0 ppm for Aroclor 1254 (correlations of 0.97 and 0.98 respectively), 1248 (correlations 0.98 and 0.99 respectively) and 1260 (correlations 0.97 and 0.98 respectively). Reported differences in the antibody binding for the Aroclor, mixtures were not apparent through the standard curves. Also, in prior pilot analysis using C-14 labeled PCB 153, the recovery using this method was between 85 and 89%. This technique simplifies cleanup and extraction, which makes the ELISA more time efficient, economical and produces less waste than the conventional method. With a lower cost leading to a larger number of fish analyzed, health advisories will be more accurate for protecting consumer’s health.
Session 44G, Toxicology & Safety Evaluation
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