DETERMINATION OF PENTACHLOROPHENOL AND ITS HYDROCARBON SOLVENT IN WOOD, SOIL, AND WATER BY GAS-CHROMATOGRAPHY AND FT IR SPECTROSCOPY IN A SINGLE-SAMPLE TREATMENT

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 FTIR spectroscopy. The distinctive feature of t his method is that both the PCP and the oil are extracted from a singl e 1-g sample. They are first extracted from the wood or soil samples w ith a 1:1 mixture of Freon 113 and methanol using ultrasonication. An aliquot of the resulting organic phase is then added to an aqueous pha se buffered at pH 9.2 with Na2HPO4. The oil remaining in the organic p hase is analyzed by FT-IR, whereas the PCP in the aqueous phase is ace tylated by reaction with acetic anhydride, back-extracted in Freon 113 , and injected into the gas chromatograph. Low-PCP-content water sampl es (<5 mu g/L) are acidified and extracted in Freon 113, which is then added to the aqueous phase. High-PCP-content water samples (>5 mu g/L ) are buffered and treated as the buffered aqueous phase. Extraction r ecoveries for the different matrices range from 94 to 115%. The absolu te detection limits (3 sigma) for PCP and the hydrocarbon solvent are respectively 28 ng and 0.1 mg for a 1-g solid sample or a 100-mL volum e of water sample. The PCP content of wood samples was compared with t hat obtained by neutron activation analysis and correlated with a 0.97 coefficient. The precision of the analytical 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.