月乃汤中甘草的鉴别及甘草酸含量测定

Identification and Determination of Glycyrrhizic Acid in Yue-nai-tang Decoction

为了建立月乃汤中甘草定性鉴别和甘草酸含量测定方法，进行月乃汤的定性鉴别：以高效液相色谱（HPLC）法对其甘草酸进行含量测定；HPLC测定条件为，色谱柱：WelchUltimateC，。色谱柱（250mm×4．6mm，5μm）；流动相：乙腈-0．05％磷酸溶液（40：60）；流速：1．0mL／min；检测波长：237nm。结果表明，月乃汤样品溶液的薄层色谱中，在与标准品色谱相应位置上，显相同颜色斑点。甘草酸铵质量浓度在（7．8-312）μg／mL范围内线性关系良好，r=0．9998，平均回收率为99．05％，RSD为2．26％，月乃汤中甘草酸的含量为（81．69±4．07）μg／mL。薄层鉴别试验发现月乃汤中含有甘草及甘草酸；通过HPLC法测定，月乃汤中甘草酸含量（81．69±4．07）Iμg／mL。

To establish a qualitative identification method and a HPLC met hod for the determination of glycyrrhizic acid in Yue-nai- tang Decoction. TLC was used to make qualitative identification and HPLC was employed to determine the content of glycyrrhizic acid in Yue-nai-tang Decoction; The analytical column was Welch Ultimate Cm （250 mmx4.6 mm, 5 μm）; methyl cyanide-0.05% phosphoric acid solution （40 ： 60） as mobile phase; the flow rote was 1.0 mL/min and the detection wavelength was 237 nm. The results showed the spots in the chromatograms of glycyrrhizic acid in Yue-nai-tang Decoction were in the same location and color with those in the chromatograms of reference substance. The linear range for ammonium glycyrrhizinate was 7.8-312 μg/mL （ r = 0.999 8）. The average recovery was 99.05 % （RSD = 2.26%）, The average concentration of Yue-nai-tang Decoction of glycyrrhizic acid was （81.69±4.07） μg/mL. The conclusion indicate The Licorice and glycyrrhizin were found in Yue-nai-tang Decoction by The TLC method; and the HPLC method determinated that the average concentration of Yue-nai-tang Decoction of glycyrrhizic acid was （81.69±3：4.07） μg/mL. The method is accurate and reliable, and it could be used in the qualitative identification and the determination of glycyrrhizic acid in Yue-nai-tang decoction.