Analysis of ephedrine in ephedra callus by acetonitrile modified capillaryzone electrophoresis

A simple method has been developed for the quantitative determination of ep hedrine in ephedra callus. The dependence of effective mobility of ephedrin e on pH was investigated, and a simulated equation was obtained. The separa tion was performed in an uncoated capillary and detected at 185 nm. A new T ris-NaOH-H3PO4 run buffer was used and the pH was adjusted to 3.20. To incr ease the solubility of hydrophobic analytes and improve the separation effi ciency, 15% acetonitrile was used in the buffer as a modifier. The content of ephedrine in an ephedra callus sample and an ephedra herba sample were d etermined with this method, and the result was satisfactory. (C) 1999 Elsev ier Science B.V. All rights reserved.