Performance of commercially available immunoassay-based field test kits for petroleum fuel hydrocarbons in soil

On-site field analytical methods have the potential to reduce the time and cost of assessing and remediating hazardous waste sites. Immunoassay-based methods are rapidly becoming a significant component in the arsenal of field analytical methods. However, the full potential of such alternative analytical methods will not be realized until their effectiveness has been experimentally validated. In this study, the performance of two immunoassay-based test kits for the analysis of petroleum fuel hydrocarbons in soil was evaluated. One kit was used in a semiquantitative format, the other in a quantitative format. The samples analyzed were either solvent or soil spiked with either a mixture of benzene, toluene, ethylbenzene, and the three isomers of xylene (BTEX), or gasoline. Of the 50 assays made with the semiquantitative test, 5 were false positives and 1 was a false negative. A soil matrix effect was observed that could account for false-positive results. Experimental results obtained with the use of the quantitative test with the BTEX mixture (68 assays) correlated well with expected results; R2 values of 0.976–0.983 and slopes of 0.94–0.97 were obtained. With gasoline (38 assays), R2 values of 0.957–0.987 and slopes of 0.76–0.78 were obtained. The lower slopes obtained with gasoline are indicative of the lower immunoreactivity of that particular sample of gasoline relative to the BTEX mixture. © 1997 John Wiley & Sons, Inc. Field Analyt Chem Technol 1:135–144, 1997