HPLC-CAD法测定白茅根中果糖、葡萄糖和蔗糖的含量

目的：建立高效液相色谱串联电喷雾检测器（HPLC-CAD）同时测定30批白茅根样品中果糖、葡萄糖和蔗糖的方法，并对不同来源白茅根所测糖类成分的含量进行比较，为其质量标准提高提供依据。方法：采用Xbridge Amide色谱柱（4.6 mm×250 mm，3.5 μm），以乙腈-0.2%三乙胺水（75：25）为流动相，流速1 mL·min^-1，柱温30℃。结果：在建立的液相色谱条件下，上述3个糖类成分分离完全，果糖、葡萄糖、蔗糖进样量分别在2.125~12.749、2.017~12.101、5.274~31.646 μg范围内线性良好；精密度、重复性、稳定性及回收率实验结果均符合含量测定要求，果糖、葡萄糖和蔗糖进样量的平均回收率（n=6）分别为99.8%、99.8%、100.7%。30批白茅根样品中果糖、葡萄糖和蔗糖的含量分别为2.019~63.319、2.835~64.797、1.289~175.816 mg·g^-1。以3个糖为指标，经过系统聚类分析，性状有问题的样本被聚成一类，该类样品中3个糖的含量均比较低，果糖小于17.500 mg·g^-1，葡萄糖低于12.800 mg·g^-1，蔗糖多小于51.900 mg·g^-1；符合《中华人民共和国药典》规定的样本为一类，此类样品中3种糖含量较高，果糖与葡萄糖的含量大于性状有问题的样本。结论：该方法适用于白茅根中果糖、葡萄糖和蔗糖的含量测定，3个糖的测定对白茅根具有一定的鉴别意义。

Objective: To establish a method for simultaneous determination of fructose,glucose and sucrose in Imperatae Rhizoma by HPLC-CAD,and to compare the content of sugars in samples from different sources,in order to provide a foundation for the improvement of quality standard.Methods: The analysis was performed on n Xbridge Amide column (4.6 mm×250 mm,3.5 μm). The mobile phase was acetonitrile-0.2% triethylamine(75:25) at a flow rate of 1 mL·min^-1. The column temperature was controlled at 30℃.Results: Under the above chromatographic conditions,the analytes showed good linear relationship within the range of 2.125-12.749 μg for fructose,2.017-12.101 μg for glucose and 5.274-31.646 μg for sucrose. The experiment results of precision,repeatability,stability and recovery were all consistent with the requirements of content determination.The average recovery for fructose,glucose and sucrose were 99.8%,99.8% and 100.7% respectively. The contents of fructose,glucose and sucrose in 30 samples were 2.019-63.319,2.835-64.797 and 1.289-175.816 mg·g^-1,respectively. Based on cluster analysis of three sugars,30 samples were divided into two groups. A group of samples showed abnormal characteristics. The contents of three sugars in these samples were relatively low with fructose less than 17.500 mg·g^-1,glucose less than 12.800 mg·g^-1,and sucrose less than 51.900 mg·g^-1. Another group of samples was in line with the provisions of the People's Republic of Chinese Pharmacopoeia. The contents of sugars in these samples were relatively higher,and the contents of fructose and glucose were higher than those of the abnormal samples.Conclusion: The method is suitable for the determination of fructose,glucose and sucrose in Imperatae Rhizoma,which is significative for identification of the herb.