Comparison of immunochemical and HPLC-determination of polycyclic aromatic hydrocarbons in groundwater samples of a former manufactured gas plant site

Groundwater contamination and PAH-removal with a special water purification facility were monitored over several months by a PAH-immunoassay as well as by HPLC. In the enzyme- linked immunosorbent assay (ELISA) a polyclonal rabbit antiserum was applied. As test format an indirect competitive microtiter plate assay was used. The water samples could be directly measured without any extraction and purification steps. With the ELISA, the limit value for the sum of PAHs of 0.2 ppb as set by the German Drinking Water Act was certainly reached. Including 114 samples no false negative (defined as a measured concentration below 0.2 ppb) but 20 (17.5%) false positive (defined as a measured concentration above 0.2 ppb) samples were found with the immunoassay. Supposing the immunochemical results to be approximate values of the total PAH concentration then these data correlate very well (r equals 0.82, n equals 114) with the sum of the 16 EPA PAHs as measured by HPLC in this study. Therefore, the ELISA could be used as a rapid screening technique to diminish the sample number for HPLC.