几种茶叶中铝含量的测定

本文尝试水杨基荧光酮作显色剂来测定茉莉花茶、苦丁茶和红茶三种常见茶叶的铝含量。在波长559nm处,对浓度在0～5μg/(25ml)范围内的铝标准溶液的吸光度进行测定,结果表明其吸光度与浓度有良好的线性关系,标准工作曲线回归方程为C=0.2826A+0.0044,相关系数r=0.9992(n=5),回收率在93%～103%之间,标准偏差小于0.000242,变异系数小于0.65%,有较高的精密度。此法操作简单,精密度、回收率都较好,适用于测定茶叶中的铝含量。

Determination of the Aluminum in Several Teas

In this article, the salicyl fluorescence alkone is used as color reagent to determine the contents of the aluminum in jasmine tea, kuding tea and black tea. The calibration curve is figured by determining the standard aluminum solution at 559nm. The content of the standard solution is from 0 to 5μg/25ml. The regression equation is C=0.2826A+0.0044, correlation coefficient r=0.9992(n=5), the recovery is from 93% to 103%. The standard deviation is 0.000242, and variation coefficient is less than 0.65%. This method, for the determination of content of aluminum in teas is simple, and the accuracy and the recovery are satisfied. The method is suitable to determinate the content of aluminum.