Separation of eleven priority phenols by capillary zone electrophoresis with ultraviolet detection

The separation and detection of eleven priority phenols using capillary zone electrophoresis with UV detection are described. Using a 70 cm x 75 mu m I.D. capillary at 15 kV and an electrophoretic buffer of 20 mM sodium berate (pH 9.9 +/- 0.1), the eleven compounds could be completely separated in less than 14 min. The different variables that affect separation were studied and optimized, and good linearity was obtained between 0.5 and 20 mg l(-1) for 2,4-dimethylphenol (2,4-DMP) and between 0.25 and 20 mg l(-1) for the other compounds, and the detection limits were 0.1 mg l(-1) for all compounds except 2,4-DMP (0.25 mg l(-1)). Previous analyses of real samples, an off-line solid-phase extraction process with a highly cross-linked styrene-divinylbenzene copolymer cartridge was used to determine the priority phenolic compounds at low mu g l(-1) levels. The method was tested with tap and Ebro river waters.