莓茶代用茶总黄酮检测方法优化

Optimization of Detection Method of Total Flavones in Ampelopsis grossedentata Tea-Like Drink

为了建立准确、简便、灵敏、重现性好的莓茶代用茶中总黄酮(以二氢杨梅素计,下同)的检测方法,特对检测试剂、检测波长、显色反应条件等进行优化。结果表明:用70%乙醇50℃超声提取4次(提取率达99.814%),以三氯化铝和醋酸钾进行显色反应,在294 nm波长处检测吸光度值,获得标准曲线方程Abs=0.04374 C×0.01236,相关系数为0.99994,线性范围2.48~19.84μg/mL。经验证,该检测方法重现性良好,相对标准偏差RSD(n=5)为0.9807%;精密度良好,相对标准偏差RSD(n=5)为0.0929%~0.4155%;显色反应1 h内稳定性良好,吸光度值及检测浓度值相对标准偏差RSD(n=5)为0.565%~1.178%。该方法最低检测浓度为0.35μg/mL。

To develop an accurate,simple,sensitive and repeatable method for the detection of total flavones(calculated in dihydromyricetin)in Ampelopsis grossedentata tea-like drink(one of tea substitutes),the optimization for test reagents,detection wavelength selection and color reaction was made.Ultrasonic extraction was conducted with 70%ethanol at 50°C for 4 times(the extraction rate was 99.814%),color reaction was performed with aluminum trichloride and potassium acetate,the absorbance value was measured at 294 nm,then a standard curve equation Abs=0.04374×C-0.01236 was constructed where the correlation coefficient was 0.99994,and the linear range was 2.48~19.84μg/mL.The results have proved that the method is of a good repeatability with the relative standard deviation RSD(n=5)of 0.9807%,and high accuracy with the RSD(n=5)of 0.0929%~0.4155%.The color reaction is stable within 1h,and the RSD(n=5)is 0.565%~1.178%for the absorbance value and the detected concentration value.The minimum detection concentration of this method is 0.35μg/mL.