PAH RIS® Soil Test—A Rapid, On-Site Screening Test for Polynuclear Aromatic Hydrocarbons in Soil

Abstract

Abstract Polynuclear aromatic hydrocarbons (PAHs) are chemicals of concern when they contaminate the environment. Current detection methods (gas chromatography and liquid chromatography) are laborious, time consuming, and expensive. As an alternative, we developed a competitive enzyme-linked immunosorbent assay kit that can be used on site for the detection of PAHs at 1 ppm in soil. The immunoassay kit includes all the components necessary to conduct the analysis in the field. The test consists of 3 major steps: (1) sample treatment; (2) immunoassay, in which the target compound is bound by a specific antibody followed by the development of an indicator color; and (3) interpretation of results. A sample that develops less color than the standard is interpreted as positive (soil sample contaminated with PAHs at ≥1 ppm). Validation studies demonstrated that the assay is sensitive and specific. The assay detects PAH contamination in soil at 1 ppm or greater and specifically detects the 3- and 4-ringed aromatics and most of the 5-and 6-ringed aromatics. PAH-free soil samples gave negative results in the assay at a confidence level of >95%. Matrix effects, interperson, and interlot variations were minimal. The test requires <25 min to complete. The test kit is field compatible and provides a cost effective method for screening soils at risk for PAH contamination.