CE Determination of Four Major Constituents in Sang-Xing Decoction

Abstract

Capillary electrophoresis coupled with photodiode array detection was employed for the determination of four major constituents in traditional Chinese herbal formula ‘Sang-Xing Decoction’. The sample was extracted under recirculation with 70% ethanol for 2 h at 90 °C. The chromatographic separation was performed on a fused silica capillary tube (75.0 cm total length, 66.5 cm effective length, 75 μm ID.) with an applied voltage of 20 kV at 25 °C. The buffer mixture (pH = 6.80) of 0.05 mol L⁻¹ Na₂B₄O₇·10H₂O and 0.2 mol L⁻¹ KH₂PO₄ was used as the separation buffer. The calibration curve for the determination of all the analytes showed good linearity over the investigated ranges (R ² > 0.999).The intra- and inter-day assay precision (RSD) of the four analytes were in the range of 0.88–2.61% and the recoveries were between 95.6 and 102.5%. The validated method was successfully applied to the determination of four major constituents in ‘Sang-Xing Decoction’ for quality control.