Separation and determination of aconitine alkaloids in traditional Chinese herbs by nonaqueous capillary electrophoresis

An easy, rapid, and simple nonaqueous capillary electrophoresis (NACE) method was developed for the identification and determination of three aconitine alkaloids, hypaconitine (HN), aconitine (AN), and mesaconitine (MN) within 6 min. The most suitable running buffer was composed of 60 mM ammonium acetate, 0.5% acetic acid, and 15% acetonitrile (ACN) in methanol with a fused-silica capillary column (50 cm x 75 microm ID). In the concentration range 12.5-1000 mg/L the calibration curves reveal linear relationships between the peak area for each analyte and its concentration (correlation coefficients: 0.9997 for HN, 0.9999 for AN, and 0.9995 for MN). The relative standard deviations of the migration time and peak area of the three alkaloids were 0.13, 0.57, 0.33 and 2.87, 1.06, 3.49%, respectively. The method was successfully applied to determine the three alkaloids in two commonly used traditional Chinese herbal medicines, the recoveries of the three constituents ranging between 94.7-101.9% for HN, 98.3-102.3% for AN, and 98.1-104.6% for MN.