Determination of pentachlorophenol (PCP) in samples of the environmental specimen bank using isotope dilution

Within the program of the Environmental Specimen Bank a quick and efficient method for determination of pentachlorophenol (PCP) in various environmental matrices has been developed. The method includes alkaline hydrolysis of bound PCP, acidification, simultaneous steam distillation and extraction in one glass apparatus. After clean-up and derivatization with acetic anhydride the samples were analyzed by gas chromatography/mass spectrometry. Concentrations were calculated using ¹³C-labeled PCP as the internal standard. Validation was carried out with various environmental samples (soil, fish, conifer needles, kale). The method can be used for various biological samples without any modification. The extracts are free of matrix components (lipids, chloropyll, terpenes, etc.) and other contaminants, which results in clear chromatograms with few peaks; therefore, correct integration is facilitated. Although the recoveries of PCP are in the range of 50-90%, due to losses during the several method steps, these losses can be corrected with the ¹³C-labeled internal standard, resulting in high precision (1.5-2.2% standard deviation).