Determination of Pentachlorophenol and its Hydrocarbon Solvent in Wood, Soil, and Water by Gas Chromatography and FT-IR Spectroscopy in a Single-Sample Treatment

Abstract

This analytical method offers a new way of measuring pentachlorophenol (PCP) in soil, wood, and water samples by gas chromatography and its hydrocarbon solvent by FT-IR spectroscopy. The distinctive feature of this method is that both the PCP and the oil are extracted from a single 1-g sample. They are first extracted from the wood or soil samples with a 1:1 mixture of Freon 113 and methanol using ultrasonication. An aliquot of the resulting organic phase is then added to an aqueous phase buffered at pH 9.2 with Na 2 HPO 4 . The oil remaining in the organic phase is analyzed by FT-IR, whereas the PCP in the aqueous phase is acetylated by reaction with acetic anhydride, back-extracted in Freon 113, and injected into the gas chromatograph. Low-PCP-content water samples ( 5 μg/L) are buffered and treated as the buffered aqueous phase. Extraction recoveries for the different matrices range from 94 to 115%. The absolute detection limits (3) for PCP and the hydrocarbon solvent are respectively 28 ng and 0.1 mg for a 1-g solid sample or a 100-mL volume of water sample. The PCP content of wood samples was compared with that obtained by neutron activation analysis and correlated with a 0.97 coefficient. The precision of the analitycal method is better than 10% for both analytes. This analytical approach was successfully applied to the radial characterization of freshly treated poles for their PCP and oil contents