Determination of Baicalein, Wogonoside, Wogonin and Chlorogenic Acid in Yinhuang Capsules by Capilary Electrophoresis

A CE method was established for the determination of baicalein, wogonoside, wogonin and chlorogenic acid in Yinhuang capsules. An uncoated fused silica capillary was used with 40mmol/L borax solution -15mmol/L β-CD buffer solution (pH 9.35) as running buffer at applied voltage of 12kV and detection wavelength of 280nm. The sample was injected by gravitational force. p-Aminobenzoic acid was used as the internal standard. The linear ranges of baicalein, wogonoside, wogonin and chlorogenic acid were 2.5 -12.5, 10 -80, 1.25 -10.0 and 15 -120μg/ml, respectively. The average recoveries were 104.6%, 97.2%, 98.5% and 95.8%, with RSDs of 1.71%,2.91%, 2.09%,2.83%, respectively.