TRACE ENRICHMENT OF CHLORINATED PHENOLS FROM DRINKING-WATER ON CHEMICALLY BONDED SORBENTS FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A method for the determination of seven chlorinated phenols, including those in the US Environmental Protection Agency list of priority poll utants, in drinking water is described. Solid-phase extraction on vari ous alkylsilica bonded phases such as phenyl-, octyl- and octadecylsil ica was used for sample preconcentration. The dependences of recovery on the eluent volume, sample pH and sample volume were investigated fo r all the sorbents in order to find the optimum sorbent. Octadecylsili ca was found to be the most efficient sorbent. The sample pH was adjus ted to 5.0 and, after concentration, the analytes were eluted with 1.2 cm(3) of acetonitrile-0.012 mol dm(-3) phosphoric acid (9 + 1). The e xtract was submitted to reversed-phase highperformance Liquid chromato graphy with acetonitrile-0.007 mol dm(-3) phosphoric acid (51 + 39) as the eluent and ultraviolet detection at 225 nm. Recoveries after 28 d of storage in a refrigerator at 3 degrees C were also studied. The re sults were found to agree with those before storage. A comparison betw een Bakerbond C-18 and Separcol C-18 is presented. The results obtaine d were comparable for both types of octadecylsilica. The recoveries of seven chlorinated phenols were higher than 88%. Extracting a 1 dm(3) water sample, a detection limit of 2.6 pg dm(-3) was determined for 2- chlorophenol and detection limits between 0.12 and 0.38 lug dm(-3) wer e obtained for the other six chlorinated phenols.