Evaluation of enzyme-linked immunosorbent assay for the determination of polycyclic aromatic hydrocarbons in house dust and residential soil

Two commercially available enzyme-linked immunosorbent assays (ELISA) for t otal polycyclic aromatic hydrocarbon (PAH) and carcinogenic PAH (C-PAH) wer e evaluated. The testing procedures were refined for application to screeni ng PAH and C-PAH in house dust and soil samples for human exposure studies. The overall method precision expressed as percent relative standard deviat ion (%RSD) of triplicate real world dust and soil samples was within +/-29% (12-29%) for PAH ELISA and +/-21% (5.9-21%) for C-PAH ELISA. Spike recover ies from real world dust/soil samples were 114 +/- 30% for phenanthrene fro m PAH ELISA and 120 +/- 8.2% for benzo[a]pyrene from C-PAH ELISA. The overa ll method accuracy for PAH and C-PAH assays Cannot be assessed for multiple PAH components in dust/soil samples (which represent real-world samples), because of the assays' cross reactivities with other PAH components. Over 1 00 dust/soil samples from 13 North Carolina homes and 22 Arizona homes were analyzed by PAH and C-PAH assays, as well as by the conventional gas chrom atography/mass spectrometry (GC/MS) method. Statistical analysis showed tha t dust/soil PAH data from ELISA and GC/MS methods are significantly differe nt. In general PAH ELISA responses were higher than PAH GC/MS responses. Th e regression analysis showed that the linear relationship between ELISA and GC/MS measurements is not strong in the combined data. The relationship be came stronger for the data from the same type of dust/soil samples. The scr eening performance of ELISA was evaluated based on the frequency distributi on of ELISA and GC/MS data. The results indicated that the ELISA PAH and C- PAH assays cannot be used as a quantitative analytical tool for determining PAH in real-world dust/soil samples. However, the ELISA is an effective sc reening tool for ranking PAH concentrations in similar types of real world dust/soil samples. (C) 1998 Elsevier Science B.V. All rights reserved.