三波长-分光光度法测定普洱茶中的总黄酮

以芦丁为对照品,AlCl3为显色剂,采用三波长-分光光度法测定普洱茶中总黄酮的含量。结果表明,黄酮质量浓度在3.92—39.2μg.mL-1范围内,分别在λ1=370nm、λ2=420nm、λ3=480nm处测定吸光度时,ΔA与浓度呈良好的线性关系,相关系数r=0.9998,平均回收率为100.15%,相对标准偏差为1.92%。方法的准确度与精密度均令人满意,而且操作简单。

Determination of Total Flavonids in Pu-Er Tea by Three Wavelength Spectrophotometry

The content of total flavonids in pu-er tea was determined by three wavelength spectrophotometry with rutin as a reference substance and aluminum trichloride as a chromogenic agent.The experimental results demonstrated there was the good linear relationship between mass concentration of total flavonids with ΔA in the range of 3.92—39.2μg·mL-1 with correlation coefficient of 0.9998,when the absorbance was measured at wavelength λ1,λ2 and λ3 of 370,420nm and 480nm,and the average recovery was 101.15%,while RSD was 1.92%.The method has simple operation with satisfactory accuracy and precision.