Determination of alkaloids in Sophora flavescens ait. and Sophora viciifolia Hance by capillary zone electrophoresis

Capillary zone electrophoretic (CZE) separation of pharmacologically active alkaloids, matrine, sophocarpine, sophoridine, oxymatrine, and oxysophocarpine, was systematically optimized, and their contents in different parts of Sophora species were quantitatively determined within 16 min under the following optimized conditions: 0.04 mol/L citrate buffer system at pH 4.5, applied voltage 30 kV, capillary temperature 25°C, and diode array detection at 201 nm. The recoveries are from 90 to 108%, with repeatability ranging from 0.7 to 4.2% (relative standard deviation) and the detection limits ranging from 0.032 to 0.070 mg/mL (signal to noise ratio=3). The proposed CZE method is suitable for routine analysis and quality control of herbal medicines that contain these alkaloids. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 221–226, 2001