毛细管电泳-电化学检测法用于中药石韦中绿原酸和槲皮素的同时测定
The Simultaneous Determination of Chlorogenic Acid and Quercetin in Folium Pyrrosiae by Capillary Electrophoresis with Electrochemical Eetection
-
摘要: 建立了毛细管电泳同时分离测定中药石韦中绿原酸、槲皮素含量的分析方法.采用柱端喷壁式三电极系统的电化学检测方式, 工作电极为0.5 mm碳圆盘电极;参比电极为Ag/AgCl;辅助电极为铂丝电极.以70 cm(o.d.360μm,i.d.25μm)的熔融石英毛细管为分离通道,在最佳电泳介质(pH=7.0,10.0 mmol/L磷酸盐缓冲溶液)中,当分离电压为21 kV时,两待测物质在8 min内完全分离.在最佳分离、检测条件下,响应电流与浓度之间的线性关系良好,绿原酸、槲皮素的线性方程分别为:y=0.268x+1.088、y=0.312x+0.822,相关系数大于0.999,绿原酸、槲皮素检测限分别达0.075μg/mL和0.020μg/mL.该方法具有良好的重现性,峰电流的RSD小于3.5%.已成功的用于实际中药石韦和模拟血样中绿原酸、槲皮素的含量测定,结果令人满意.Abstract: Capillary electrophoresis with electrochemical detection was applied to determination of quercetin and chlorogenic acid in Folium Pyrrosiae in the first time. The two analytes could be well separated within eight min in a 70 cm capillary (25μm I.D.) with a separation voltage of 21 kV in a 10 mmol/L of phosphoric acid buffer solution (pH=7.0). The system demonstrated good long-term stability and reproducibility with an RSD of less than 3.5% for peak height. The detection limit of three components was 0.075 μg/mL (chlorogenic acid), 0.02 μg/mL (quercetin), respectively. Contents of chlorogenic acid and quercetin in the crude drug of Folium Pyrrosiae could be easily determined by the proposed method with satisfactory results.