原子荧光光谱法测定不同产地茶叶中As，Se，Hg和Bi四种元素含量

收集了21种中国茶叶和五种日本茶叶，经过微波或湿法消解后，采用原子荧光光谱法(AFS)测定了As, Se, Hg和Bi四种元素的含量，并用植物标准参考物质评价了分析方法的准确度。另外，还探讨了As, Se, Hg和Bi在幼龄茶树不同部 位的含量分布特征。研究结果表明：微波消解对于获得较为准确的茶叶中Hg含量分析结果必不可少；与日本茶叶相比，中国茶叶中As, Se, Hg和Bi元素含量显著偏高，但君山银针中Bi含量最低；As, Se和Hg主要积累于幼龄茶树的树皮、根 系、老叶等部位，而Bi在幼龄茶树根系、去皮树干中含量则低于AFS检测限。从本次研究结果可以初步断定，茶树并非是一种Se积累植物，中国茶叶中人体必需微量元素Se主要来源于大气气溶胶的干、湿沉降。

Studies on Contents of Arsenic,Selenium,Mercury and Bismuth in Tea Samples Collected from Different Regions by Atomic Fluorescence Spectrometry

After microwave or wet decomposition, the contents of arsenic, selenium, mercury and bismuth in twenty-one Chinese tea samples and five Japanese tea samples were determined by atomic fluorescence spectrometry, and plant standard reference materials were used to verify the accuracy and the precision of the analytical method. Moreover, the contents of these four elements were also determined in different parts of tea sapling sampled from the suburbs of Suzhou, a place famous for its Chinese tea biluochun. It was shown that microwave decomposition is indispensable for getting good results of mercury contents in tea samples by AFS. Compared with those in Japanese tea samples, the contents of arsenic, selenium, mercury and bismuth in Chinese tea samples are significantly high, but the Chinese tea sample produced in Hunan province has the lowest bismuth content. Arsenic, selenium and mercury are mainly present in the bark, the root and the old leaves of tea sapling, nevertheless, the bismuth contents in the root and the bark-deprived trunk are so low that they can not be determined accurately. From this study, a preliminary conclusion can be drawn that tea is not a selenium-accumulating plant and the great majority of selenium in Chinese tea samples originates from the dry and wet deposition of atmospheric aerosols.