氢化物发生-原子荧光法测定中药中痕量汞

应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术，采用HNO₃-H₂O₂体系和聚四氟乙烯高压釜消解中药样品，并优化了实验条件，建立了氢化物发生-原子荧光法测定中药中痕量汞。同时，研究了硼氢化钾浓度，光电管负高压，灯电流，原子化器高度，屏蔽气和载气流量等因素对测定结果的影响。在选定实验条件下，汞的检出限为0.021 μg·L-1, 桃叶(GBW08501)验证结果与推荐值一致，6次测定结果相对标准偏差为0.34%。此方法简便、快速、灵敏、准确，以工作曲线法和加入作图法对照，对于实际中药样品的测定得到了满意的结果。

Determination of Trace Mercury in the Chinese Traditional Medicine by Hydride Generation-Atomic Fluorescence Spectrometry

A hydride generation atomic fluorescence spectrometry method has been developed for the determination of trace mercury in traditional Chinese medicines. A high-pressure digestion using HNO3-H2O2 system was applied to the pretreatment of traditional Chinese medicine samples and an interval flow precedure was used. The experimental conditions and instrumental operation parameters such as KBH4 concentration, flow rates of carrier and shield gases, currents of lamp and height of atomic oven, which affect the determination, have been optimized respectively as 0.05%, 400 and 800 mL x min(-1), 20 mA and 6 mm. Under the optimum conditions, there is a linear relationship between the fluorescence intensity and the mercury concentration with correlation coefficient of 0.9999, while the detection limit is 0.021 microg x L(-1). Trace mercury in the standard reference substance peach leaf (GBW08501, produced by the Environmental Science Committee of Chinese Scientific Institute) was also determinated in this way and the results of six times were in good agreement with the certified value, with a variation coefficient not more than 0.34%. This method is simple, rapid, sensitive, convinent and accurate, so it can be successfully used for the determination of trace mercury in traditional Chinese medi-