Capillary Electrophoretic Separation and Determination of Chlorophenolic Pollutants in Industrial Waste Waters

Abstract

Capillary zone electrophoresis was applied to analyze chlorophenols in industrial waste waters, 17 chlorophenols could be all resolved from each other within 12 min using acetone as the organic modifier in 10 mmol/L phosphate electrolyte at pH 8.23. Effects of pH and organic modifiers on the separation selectivity were investigated. The results indicated that the elution order was related with the pKa order of analytes. Reproducibilities termed in R.S.D.% of migration times and peak areas of 17 chlorophenols were in the range 0.48–0.67% and 3.9–5.1%, respectively. When 2,3,4-trichlorophenol was used as the internal standard, R.S.D.% of migration times was reduced to 0.03–0.28%. Detection ranges of all chlorophenols were linear over two orders of magnitude of concentrations with correlation coefficients 0.998–1.000 except for 4-chlorophenol, the peak area of which could not be measured accurately because of the interference from electroosmotic flow (EOF). Limits of detection were 100–270 μg/L. With the method developed chlorophenolic pollutants in industrial waste waters could be analyzed by direct injection without any pretreatment.