Non-chromatographic speciation analysis of mercury by flow injection on-line preconcentration in combination with chemical vapor generation atomic fluorescence spectrometry
Non-chromatographic speciation analysis of mercury by flow injection on-line preconcentration in combination with chemical vapor generation atomic fluorescence spectrometry
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DOI：
10.1016/j.sab.2006.04.008
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发表时间：
2006-07
期刊：
影响因子：
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通讯作者：
Hong Wu;Yan Jin;Weiying Han;Q. Miao;S. Bi
中科院分区：
文献类型：
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作者：
Hong Wu;Yan Jin;Weiying Han;Q. Miao;S. Bi
以二乙基二硫代磷酸铵和二硫腙为络合剂，在结式反应器内壁选择性保留无机汞和甲基汞的基础上，建立了流动注射在线吸附预富集-化学气相生成非色散原子荧光光谱法直接形态分析汞的新方法。在pH为2.0的条件下，利用Hg-DDP配合物在甲基汞存在下的排他保留，通过与二乙基二硫代磷酸二乙酯溶液在线合并，在结式反应器内壁上进行了无机汞的预富集，用双硫腙代替二乙基二硫代磷酸二乙酯溶液实现了甲基汞的选择性预富集。加入15% （v/v）的HCl洗脱残留汞，与kbh4溶液融合，进行原子荧光光谱检测。在最佳实验条件下，无机汞和甲基汞的样品通量分别为30和20 h−1，增强因子分别为13和24。Hg2+的检出限为3.6 ng l−1，CH3Hg+的检出限为2.0 ng l−1。每0.2 μg l−1 Hg2+和CH3Hg+的11个重复测量的精密度（RSD）分别为2.2%和2.8%。所开发的方法通过对认证标准物质（模拟天然水、米粉和猪肉）的分析和对加标样品的回收率测量进行了验证，并应用于生物和环境水样中无机汞和甲基汞的测定。
A novel non-chromatographic approach for direct speciation of mercury, based on the selective retention inorganic mercury and methylmercury on the inner wall of a knotted reactor by using ammonium diethyl dithiophosphate and dithizone as complexing agents respectively, was developed for flow injection on-line sorption preconcentration coupled with chemical vapor generation non-dispersive atomic fluorescence spectrometry. With the sample pH kept at 2.0, the preconcentration of inorganic mercury on the inner walls of the knotted reactor was carried out based on the exclusive retention of Hg–DDP complex in the presence of methylmercury via on-line merging the sample solution with ammonium diethyl dithiophosphate solution, and selective preconcentration methylmercury was achieved with dithizone instead of ammonium diethyl dithiophosphate. A 15% (v/v) HCl was introduced to elute the retained mercury species and merge with KBH4solution for atomic fluorescence spectrometry detection. Under the optimal experimental conditions, the sample throughputs of inorganic mercury and methylmercury were 30 and 20 h−1with the enhancement factors of 13 and 24. The detection limits were found to be 3.6 ng l−1for Hg2+and 2.0 ng l−1for CH3Hg+. The precisions (RSD) for the 11 replicate measurements of each 0.2 μg l−1of Hg2+and CH3Hg+were 2.2% and 2.8%, respectively. The developed method was validated by the analysis of certified reference materials (simulated natural water, rice flour and pork) and by recovery measurements on spiked samples, and was applied to the determination of inorganic mercury and methylmercury in biological and environmental water samples.