Evaluation of anti-pyrene and anti-fluorene immunosorbent clean-up for PAHs from sludge and sediment reference materials followed by liquid chromatography and diode array detection

Abstract

The determination of polycyclic aromatic hydrocarbons (PAHs) in complex matrices such as sludges or sediments was performed by off-line enrichment using four different immunosorbents (IS). These IS are anti-fluorene and anti-pyrene antibodies immobilized on silica. The method involves the extraction of PAHs from water samples onto either two anti-fluorene or two anti-pyrene IS followed by analysis using liquid chromatography with diode array detection (LC-DAD) and its validation using gas chromatography coupled to a mass spectrometer (GC-MS). The procedure also uses a solubilizer to limit unwanted adsorption on vessels or tubing. In order to be able to evaluate the four IS, we have analyzed environmental sediments and sludge reference materials containing PAHs. Sediments were extracted by sonication with dichloromethane–methanol (2∶1) and the extracts were brought up to a volume of 100 mL of water in order to perform the extraction with the anti-fluorene and anti-pyrene IS. This method was optimized for 13 of 16 PAHs included in the Environmental Protection Agency US (EPA) priority list. The selectivity of the IS cleanup and the LC-DAD spectra allowed a good identification and quantification in the analysis of sediment and sludge complex samples containing the priority PAHs established by the EPA. The results obtained with the four IS were compared after determination of PAHs in complex sewage sludge and sediment reference matrices. Moreover, clean-up using IS was compared with conventional clean-up procedures and showed a better selectivity for PAHs by the IS procedures.