Fast Screening of Polycyclic Aromatic Hydrocarbons (PAHs) in Contaminated Water and Soil Samples with Immunological and Chromatographic Methods

To investigate the applicability of immunological methods as sensitive and cost-effective analytical screening tools a pyrene immunoassay was developed that can be used for the semiquantitative detection of PAHs in water and soil. While contaminated groundwater samples from a former gas plant site could be analyzed directly, soil and seepage water has to be extracted and require at least 1:100 dilution prior to immunochemical measurement. PAHs could be recovered from fortified reference soils as well as aged field samples with high yield using 1-hour ultrasonication with acetonitrile. Extraction efficiency was lower with agitation but was acceptable as part of an on-site field test to provide rapid, semiquantitative, and reliable test results for making environmental decisions such as identifying “hot spots”, site mapping, monitoring of remediation processes, and selecting site samples for laboratory analysis. Using classification of ELISA data an estimation of the PAH contamination in soils (n=18) was possible put up with about 5% false positive and 5% false negative results that may be caused by the heterogeneity of samples, PAH-profile, cross-reactive compounds, or unknown matrix interferences.