杜仲叶中总黄酮检测方法的改进研究

Improvement on the Identification of Flavonoids in Leaves of Eucommia Ulmoides Oliver

黄酮是杜仲叶中的一种活性成分,NaNO2-A(lNO3)3法作为总黄酮检测中普遍使用的方法从20世纪90年代沿用至今,但由于绿原酸的干扰,使得采用该法检测富含绿原酸原料中的总黄酮含量,检测结果往往偏高或不真实。本文考察了采用NaNO2-A(lNO3)3法绿原酸对总黄酮的检测结果的干扰,并找到适用于富含绿原酸的原料中总黄酮化合物的检测方法。通过比较和分析确定以ZrOCl2作为显色剂采用分光光度法对杜仲叶中总黄酮含量进行检测,确定了优化检测条件:2%ZrOCl2甲醇溶液2 mL,醋酸-醋酸钠缓冲液添加量1 mL,放置时间70 min,在440 nm波长处检测。在1.25μg/mL^20μg/mL范围内,芦丁浓度与吸光度呈良好线性关系,回归方程为y=0.033 6x+0.001 9,相关系数R2=0.999 4,精密度实验RSD值为1.587%,样品平均加标回收率为101.63%。

Flavone is one of the active ingredients in leaves of Eucommia ulmoides Oliver. Since 1990 s, it is the method of NaNO2-Al （NO3）3 that is most widely used in the identification of total flavonoids. However, due to the interference effect of chlorogenic acid, the detection result of flavone is usually inaccurate or higher than the real percentage. This research studies the chlorogenic acid＇s interference by the method of NaNO2-Al （NO3）3 and build a more suitable method in identifying total flavonoids for raw materials which is rich in chlorogenic acid. By comparing and analyzing, we built an improved spectrophotometry which required 2 mL of 2 % ZrOCl2 solution as chromogenic reagent, lmL of acetic acid and sodium acetate buffer solution, a standing time of 70 min and a scan wavelength of 440 nm. The results showed that a good linear relationship （y=0.033 6x＋0.001 9 R^2= 0.999 4） between OD and concentration of rutin within the range of 1.25 μg/mL-20 μg/mL. The average recovery rate is 101.63 % with RSD 1.587 %.