A novel method of reversed migration capillary electrophoresis for determination of linear alkylbenzene sulfonates

A reversed migration capillary electrophoresis (RMCE) has been developed to determine linear alkylbenzene sulfonates (LAS). The sample stacking and separation conditions have been systematically investigated and optimized under reversed separation voltage at a low pH value. The separation effect of LAS homologs has been greatly improved based on the relative motion of electrophoresis and electroosmotic flow. RMCE demonstrates a good linear range of 0.1 mg/l to 10.0 mg/l, and the detection limit of LAS homologs reaches 0.001–0.004 mg/l. The relative standard deviations (n=6) of peak area and migration time were 2.25–4.40% and 0.67–0.75%, respectively. RMCE has also been applied for LAS detection in practical wastewater. The results show RMCE exhibits easy pretreatment, fast detection, high sensitivity, good peak shapes and resolution, and less solvent consumption, compared with the established high-performance liquid chromatography method.