Determination of metabolites of benzene, toluene, ethylbenzene, and xylene by beta-cyclodextrin modified capillary electrophoresis

Abstract

A beta-cycloclextrin modified capillary electrophoresis method for determining the metabolites of benzene, toluene, ethyl benzene, and xylene (BTEX) is described. Creatinine and uric acid were also examined as reference compounds. By employing a 20 mM, pH 10.0 borax-NaOH buffer containing 7-mM of beta-CD, ten analytes could be successfully separated within 10 min on a 50 pm capillary at an electric potential of 25 kV. The effects of pH and the concentration of beta-CD on the separation of the ten analytes are discussed. Under optimized separation conditions, the relative standard deviations for the migration times of the analytes were less than 0.93% and the correlation coefficients of the analyte linear calibration graphs exceeded 0.998 in the range from 1 to 300 mug/mL. Analyses of BTEX metabolites in urine samples from both occupationally exposed and non-exposed subjects are shown herein. BTEX metabolites were determined in the urine sample of a gas station attendant.