原子荧光法测定茶叶中的硒含量

采用原子荧光法测定茶叶中的硒含量,对样品消解温度及仪器条件进行了优化。还原剂为1.0%硼氢化钾–0.5%氢氧化钾溶液,载流液为3%盐酸溶液。在优化条件下,硒的质量浓度在0~20 ng/mL范围内与荧光强度呈良好的线性关系,相关系数r=0.999,检出限为0.8 ng/mL。该法的加标回收率为88.08%~101.39%,测定结果的相对标准偏差为2.03%~4.84%(n=6)。该方法实际操作性强,准确度高,适用于日常检验工作中对批量茶叶中硒含量的测定。

Determination of Selenium Content in Tea by Atomic Fluorescence Spectrometry

The determination of selenium in tea by atomic fluorescence spectrometry was established. The digestion temperature and instrument conditions were optimized. The reducing agent was 1.0% potassium borohydride–0.5%potassium hydroxide solution and the carrier liquid was 3%hydrochloric acid solution. Under the optimized conditions, the concentration of selenium was linear with fluorescence intensity in the range of 0–20 ng/mL,the linear correlation coefficient was 0.999. The recovery of the method ranged from 88.08%to 101.39%. The relative standard deviation of detection results was 2.03%–4.84%（n=6）. The method is feasible,has high accuracy,and it was suitable for determination of selenium in bulk tea for routine inspection work.