Immunochemical detection of polycyclic aromatic hydrocarbons and 1-hydroxypyrene in water and sediment samples
Li, Kai, Lee Ann Woodward, Alexander E. Karu, and Qing X. Li
Several approaches were investigated to fully use an enzyme-linked immunosorbent assay (ELISA) for accurate measurement of polycyclic aromatic hydrocarbons (PAHs) and their degradation products in surface water and sediments collected from the Pearl Harbor and James Campbell National Wildlife Refuges (NWRs) in Hawaii. Water samples were extracted by solid phase extraction (SPE) while the sediments were extracted by supercritical CO2. Parent PAHs and 1-hydroxypyrene, selected as a marker, were quantitatively recovered with supercritical CO2 from sediments that were mixed with 5% Na4EDTA. Use of Na4EDTA or Na2SiO3 significantly improved recovery of 1-hydroxypyrene in sediments. Na4EDTA was more effective than Na2SiO3. The concentrations of PAHs as benzo[a]pyrene equivalents determined by ELISA were slightly higher than those determined by gas chromatography; mass spectrometry (GC/MS). Overestimation’ by ELISA over GC/MS was attributed to, at least in part, the presence of PAH metabolites including 1-hydroxypyrene which were detected by ELISA, but not quantified by GC/MS.