高效毛细管电泳法分离测定不同种类甘草药材中甘草酸的含量

目的 应用高效毛细管电泳法(HPCE)测定不同种类甘草药材中甘草酸的含量。方法 缓冲液30mmol·L-1硼酸盐溶液,pH=9.2,未涂层弹性石英毛细管(75 μm×47.5 cm,有效分离长度40 cm)为分离通道,压力进样(250 Kpa·s),20 kV恒压电泳(25 C)分离,254 nm检测。结果 整个分析过程可以在7 min以内完成,甘草酸含量的线性范围为0~500μg·mL-1(r=0.999 7)。甘草酸的保留时间与甘草酸积分峰面积的RSD值分别为0.2％和3.4％。结论 该方法简洁、快速,重现性较好,适用于甘草药材中甘草酸含量的快速测定,也为进一步建立甘草药品的指纹图谱提供了可行性依据,并且,可以同时分析甘草酸的水解产物-甘草次酸,可用于进一步研究甘草类药物的代谢。

Separation and Determination of Glycyrrhizic Acid in Glycyrrhiza uralensis Fisch by High Performance Capillary Electrophoresis (HPCE)

Objective To develop a method by high performance capillary electrophoresis (HPCE) for separating and determining the Glycyrrhizinic acid (GA) content from aqueous extracts of licorice, the root of Glycyrrhiza uralensis Fisch, and compare the levels of GA in licorice from different areas. Method Water with 10% ethanol was chosen as the extraction solvent for GA. The capillary used was 75 μm in i. d.And 47. 5cm in total length (40 cm in effective length). The buffer solution used for CZE contained 30 mmol/L sodium borate at a PH of 9. 2, with a UV detection wavelength of 254 nm, voltage of 20 KV and at a temperature of 25 C. The content of GA can be calculated from calibration curve constructed with reference standards. Results The experimental results indicated that the GA was the main components of licorice. The GA yielded in the wild Glycyrrhiza uralensis Fisch is higher than those of the cultivated ones. The calibration curve showed good linearity over the range of 0-500 μg·ml 1(r = 0. 999 7). The RSD for the Retention time of GA is 0. 2% while for the peak area is 3. 4%. Conclusions A rapid method using HPCE by capillary zone electrophoresis (CZE) mode was developed for separating and determining the GA from aqueous extracts of licorice. The electrophorogram gave seven main separated peaks, which offers the possibility of fingerprinting Glycyrrhiza uralensis Fisch by HPCE. Compared to the conventional HPLC and TLC methods, the HPCE method established in this work is simpler and better suited for the analysis of Traditional Chinese Medicines (TCMs) with complex compositions. Even more, the CE method is suitable for analysis of degredation product glycyrrhetinic acid (GTA) , playing a part in probing further metabolism of the herb.