悬浮液进样原子荧光光谱法测定茶叶中的痕量汞

THE MEASUREMENT OF TRACE HG IN TEA BY ATOMIC FLUORESCENCE SPECTROSCOPY WITH SUSPENSION-INJECTION

研究了一种使用悬浮样进样原子荧光光谱法测定茶叶中的痕量汞的快速简便的方法。控制悬浮液的颗粒粒径在200目(d≤0.076mm),用磁力搅拌器搅拌以保证悬浮液分散均匀稳定。方法简单快速,灵敏度高,样品损失少,而且没有样品交叉污染。该法的检出限为0.002μg/L,加标回收率为94.5%～102.5%,RSD为2.35%。应用此法测定了2种茶叶标准参考物质以及6种市售茶叶样品中的汞含量,并与传统的高压焖罐强酸消解法进行了比较,2种方法所得结果一致,标准参考物质的测定值与标准值很好地吻合。

A simple and quick method of testing the trace Hg in the tea with suspension-injection on Atomic Fluorescence spectroscopy was used in the research. The grain in the suspension was controlled under 0.076 mm （less than 200 meshes） and the suspension was stirred with a magnetic stirrer. The advantages of this method are simple to handle, high in sensitivity, less loss in samples and no cross contamination. The detecting threshold was 0.002 μ g/L, the recovery rate lay between 94.5 %-102.5 % ,and RSD was 2.35 %, 2 standard referencing substances in tea and Hg content in 6 commercial tea were tested with this method, and the test result was compared with that from traditional method. The comparison showed that the result of this method was well coincided with that of the traditional and with the standard referencing substances in tea.