毛细管离子分析法测定茶叶中的锌、锰、铜、铅和镉

用毛细管离子分析(CIA)法测定了茶叶中的锌、锰、铜、铅和镉,在10mmol/L咪唑,10mmol/Lα-羟基乙酸,pH=4.0的电泳介质中,五种离子在10min内得到了分离,用间接紫外法检测,以外标法定量,五元素的线性关系良好,相关系数为0.9973~0.9997,平均回收率在96.4%~104.2%之间,相对平均偏差为2.1%~3.3%,检测限为0.02~0.2μg/ml。此方法快速简便、准确度高、测定成本低。

Determination of Zn, Mn, Cu, Pb and Cd in Tea by Capillary Ion Analysis

Capillary ion analysis(CIA) was used to determine the contents of Zn, Mn, Cu, Pb and Cd in tea. In the solution(pH=4.0) containing 10 mmol/L of imidazol and 10 mmol/L of α-hydroxyacetic acid, Zn, Mn, Cu, Pb and Cd in tea were separated within 10 min. Zn, Mn, Cu, Pb and Cd in tea were detected at 214 nm by indirect UV, and quantified externally. The calibration curves of five elements showed good linearity .The correlation coefficient were 0.9973~0.9997.The average recoveries were 96.4%~104.2% with RSD of 2.1%~3.3%.The detection limits were 0.02~0.2 μg/ml.The result showed that the method is convenient, rapid, accurate and lower cost. It was used in the determination of tea samples, and satisfactory results could be obtained.