Abstract: In formamide(FA) medium, the separation and determination of the effective components in Riyebaifuning tablet by nonaqueous capillary electrophoresis with electrochemical detection in the presence of TrisH₃BO₃ as the background electrolyte were reported. The effect of potential of working electrode, different concentrations of FA, pH, the concentrations of background electrolyte, operation voltage and injection time on capillary electrophoresis were discussed. At the detection potential of 0.9 V(vs. SCE), acetaminophen(AP), pseudoephedrine hydrochloride(PH), dextromethorphan hydrobromide(DM), chlorphenamine maleate(CM) were separated within 12 min by using 25mmol Tris-25 mmol H₃BO₃(pH=8.5) as a carrier electrolyte at a positive voltage of 27 kV. There are an excellent linearity between peak current and concentration of analytes in the concentration range of AP 0.5—200 mg/L; PH0.8—300 mg/L; DM 2.5-350 mg/L; CM 0.5-330 mg/L. The detection limits(S/N=3) are AP 0.1 mg/L; PH 0.55mg/L; DM 1 mg/L; CM 0.2 mg/L.

Key words: Nonaqueous capillary electrophoresis, Electrochemical detector, Effective components, Riyebaifuning