葛根中总黄酮含量测定方法比较研究

A comparative study on the content determination of Gegen(Puerariae Lobatae Radis)total flavonoids by two methods

目的:紫外-可见分光光度测定葛根总黄酮含量的两种方法(显色法、直接测定)结果具有显著差异,因此将两种测定方法与HPLC法进行对比,找出导致其差异的原因和解决方案。方法:以芦丁为对照品,采用亚硝酸钠-硝酸铝-氢氧化钠显色,通过UV法测定葛根总黄酮含量;以葛根素为对照品,直接于250 nm处测定吸光度计算葛根总黄酮含量;采用高效液相色谱法测定葛根素的含量,对比三种方法的含量差异,评价两种紫外测定法所得结果的准确性。结果:显色法测定23批野葛总黄酮含量为0.93%~8.02%,23批粉葛总黄酮含量为0.04%~1.12%,直接测定法测得23批野葛总黄酮含量为3.31%~15.74%,23批粉葛总黄酮含量为0.80%~7.59%;显色法测得葛根总黄酮含量均显著低于非显色法。HPLC测定23批葛根的葛根素含量为1.98%~5.85%,23批粉葛的葛根素含量为0.17%~2.37%。结论:显色法测定的总黄酮含量大部分低于单一成分葛根素的含量,不显色法测得总黄酮含量均高于单一成分葛根素的量。在葛根总黄酮的测定中,以葛根素为对照品的直接测定法更加合理准确。

Objective:There were significant differences in the results of the two methods(colorimetry and direct determination)for the determination of Gegen total flavonoids by UV-vis spectrophotometry,so the two methods were compared with the HPLC method to find out the reasons for the differences and solutions.Methods:With rutin as the control substance,sodium nitrite-aluminum nitrate-sodium hydroxide was used to develop color,and the content of Gegen total flavonoids was determined by UV method.With puerarin as the control substance,the content of Gegen total flavonoids was determined by measuring absorbance directly at 250 nm.The content of puerarin was determined by high performance liquid chromatography(HPLC).The content differences of the three methods were compared,and the accuracy of the results obtained by the two ultraviolet determination methods was evaluated.Results:The content of total flavonoids in 23 batches of Yege determined by colorimetry was 0.93%-8.02%and the content of total flavonoids in 23 batches of Fenge was 0.04%-1.12%.The content of total flavonoids determined by direct determination in 23 batches of Yege was 3.31%-15.74%,and the content of total flavonoids in 23 batches of Fenge was 0.80%-7.59%.The content of total flavonoids of Gegen determined by colorimetry was significantly lower than that of non-colorimetric method.The puerarin content of 23 batches of Yege determined by HPLC was 1.98%-5.85%and 0.17%-2.37%for 23 batches of Fenge.Conclusion:The content of total flavonoids determined by colorimetry is mostly lower than that of single component puerarin,and the content of total flavonoids determined by non-colorimetric method is higher than that of single component puerarin.In the determination of total flavonoids of Gegen,the direct determination method with puerarin as the control substance is more reasonable and accurate.