Improved determination of chlorophenols in water by solid-phase microextraction followed by benzoylation and gas chromatography with electron capture detection

A rapid method for the determination of chlorophenols in drinking water by solid-phase microextraction and gas chromatography with electron capture detection was developed and validated. A fused silica fiber coated with a 65 pm thick stationary phase of poly (dimethylsiloxane)/divinylbenzene was used to extract chlorophenols after performing in situ derivatisation with pentafluorobenzoyl chloride in the polymeric coating. Validation was carried out in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. In situ derivatisation and the choice of a fiber with more affinity towards the derivatised analytes gave LODs in the 0.005 - 0.8 mug L-1 range which are lower values than those reported in previous work using poly(dimethylsiloxane) or poly(acrylate) fibers. Linearity was statistically verified over one order of magnitude for each compound. The production of chlorophenols as disinfection by-products in the treatment of drinking water with chlorine was studied over a period of eight days: mono-, di- and trichlorophenols were detected and quantitated.