Determination of Chlorinated Phenols in Water, Wastewater, and Wastewater Sludge by Capillary GC/ECD

A method is described which permits the analysis of chlorinated phenols in aqueous samples at ng/l concentrations. Extraction is carried out by homogenisation with dichloromethane, clean-up by sample concentration and back extraction with alkali, and derivatisation for capillary gas chromatography/electron capture detection by extractive alkylation with pentafluorobenzoyl chloride. The method is applied to municipal wastewater treatment works effluent, digested wastewater sludge, and soil leachate and the concentrations found are reported. Eight chlorinated phenols were spiked into these samples and the mean recovery was 70% with a relative standard deviation of 7 to 15%, dependent upon sample matrix.