DETERMINATION OF EPHEDRINE AND PSEUDOEPHEDRINE IN CHINESE HERBAL PREPARATIONS BY CAPILLARY ELECTROPHORESIS

A simple, rapid and accurate capillary electrophoresis method was developed for the assay of ephedrine and pseudoephedrine in Chinese herbal preparations. The buffer solution used was a 0.01 M valine solution with the pH adjusted to 10.0 with ammonia solution (7.2 M). The linear calibration range was 0.008-0.240 mg/ml (r = 0.9996) for both compounds and the recoveries were 98.0-102.3% for ephedrine and 99.0-101.5% for pseudoephedrine. The relative standard deviation was 0.86% for ephedrine and 0.87% for pseudoephedrine (n = 6) respectively. The contents of these two alkaloids in Ephedrae Herba-containing Chinese herbal preparations could easily be determined within 3 min.