同时测定中草药中痕量铅和汞的氢化物原子荧光法

Simultaneous Determination of Trace Lead and Mercury in Chinese Herbal Medicine by Hydride Generation-Atomic Fluorescence Spectrometry

提出了同时测定痕量铅和汞的氢化物发生原子荧光法 ;采用断续流动氢化物发生器 ,以碱性铁氰化钾为氧化剂 ,在柠檬酸介质中产生铅烷和汞蒸气 ;讨论了氧化剂和络合剂对铅烷和汞蒸气生成的作用机理 ,考察了共存元素的干扰情况;在选定最佳工作条件下 ,测得铅和汞的检出限(3σ)分别为0.21μg·L-1 和0.026μg·L-1,相对标准偏差(对20μg·L-1Pb和2μg·L-1Hg,n=11)分别为1.2 %和0.71 % ;该法应用于中草药中痕量铅和汞的同时测定 。

A method was proposed for the simultaneous determination of trace lead and mercury by hydride gene_ration-atomic fluorescence spectrometry using an intermittent flow system. The volatile species generation of lead and mercury in the medium of citric acid was performed using potassium ferricyanide in potassium tetrahydroborate reduction solution as an oxidant. The working mechanism of the oxidant on hydride generation of Pb and Hg was discussed. Interference of some coexisting elements was studied systematically. Under the optimized conditions, the detection limits of the method were 0.21 μg·L-1 for Pb and 0.026 μg·L-1 for Hg, and the relative standard deviations based on the determination of 20 μg·L-1 Pb and 2 μg·L-1 Hg(n=11) were 1.2% for Pb and 0.71% for Hg. The method was applied to the analysis of Chinese herbal medicines for Pb and Hg contents, and satisfactory results were obtained.