毛细管区带电泳法测定中草药中的有机酸

阿魏酸、绿原酸、咖啡酸是三种结构相似的酚酸类化合物,本研究建立了毛细管区带电泳法测定中草药中的阿魏酸、绿原酸、咖啡酸的分析方法,以pH=8.7的150 mmol/L硼酸为缓冲溶液,在0.5 psi进样8 s,分离电压23 kV,检测波长320 nm,温度25℃的条件下进行测定。阿魏酸、绿原酸、咖啡酸的浓度在0.01~0.2 mg/mL范围内与峰面积呈良好的线性关系,线性相关系数分别为0.999,0.997和0.999,其检出限分别为0.2μg/mL、0.4μg/mL和0.2μg/mL(信噪比为3∶1)。该方法用于金银花、蒲公英、蜂胶、感冒止咳颗粒等药物中阿魏酸、绿原酸、咖啡酸含量的测定,其样品平均回收率在96.0%~100.4%之间,取得了满意的结果。

Determination of organic acids in chinese herbal medicine by capillary zone electrophoresis

A capillary zone electrophoresis method was developed for the determination of chlorogenic acid,caffeic acid and ferulic acid in some Chinese herbal medicines.The influence of the pH and concentration of the running buffer,separation voltage and injection time on separation were examined.The best separation was achieved on a fused-silica capillary column(50 cm×75 μm I.D.) in a running buffer of 150 mmol/L boric acid(pH=8.7) with injection time of 8 s at 0.5 psi and an applied voltage of 23 kV at 25℃.The detection was performed with diode array detection at 320 nm.The calibration curve was linear over a range of 0.01～0.2 mg/mL for ferulic acid,chlorogenic acid and caffeic acid,with a correlation coefficients of 0.999,0.997 and 0.999,respectively.The detection limits(S/N=3∶1) for ferulic acid,chlorogenic acid and caffeic acid were 0.2 μg/mL,0.4 μg/mL and 0.2 μg/mL,respectively.The CZE method has been successfully applied to the analysis of organic acid in honeysuckle,taraxacum and propolis.