Concentration of chlorophenols in water with sodium dodecylsulfate–γ-alumina admicelles for high-performance liquid chromatographic analysis

Chlorophenols in water were sorbed onto sodium dodecylsulfate (SDS)–alumina (γ-form) admicelles. The extent of sorption increased with increasing amount of SDS and decreasing solution pH. Conditions for good recovery were obtained when 100 mg SDS and 1.5 g alumina was used at pH 2. However, the yield decreased with a further increase in the SDS concentration due to the formation of normal SDS micelles. The extent of sorption also increased with increasing hydrophobicity of the chlorophenol, indicating that hydrophobic interactions predominate for the collection of analytes. When a cartridge column filled with admicelles was used, >90% of tetrachlorophenol and pentachlorophenol in 200 ml of water samples were rapidly recovered. The sorbed analytes were eluted with 1 ml acetonitrile. The accuracy and precision of the present method were demonstrated for the HPLC analysis with ultraviolet (290 nm) detection of μg l−1 levels of tetrachlorophenol and pentachlorophenol in river water samples.