Application of alkaline mode electrochemical hydride generation for the detection of As and Sb using atomic fluorescence spectrometry
Application of alkaline mode electrochemical hydride generation for the detection of As and Sb using atomic fluorescence spectrometry
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DOI：
10.1016/j.sab.2010.06.003
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发表时间：
2010-07
期刊：
影响因子：
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通讯作者：
Wang-bing Zhang;Xin-an Yang;Yongping Dong;X. Chu
中科院分区：
文献类型：
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作者：
Wang-bing Zhang;Xin-an Yang;Yongping Dong;X. Chu
在本研究中，我们提出了一种在碱性条件下利用电化学氢化物发生（EcHG）检测砷和锑的方法。与传统的酸性模式相比，碱性模式具有更好的抗干扰能力。此外，该方法还可以直接检测到As（III）和Sb（III）。通过预还原步骤可以检测到完全无机的As和Sb。采用循环伏安法对锑的电解还原过程进行了详细研究。结果表明，载气引入位置是影响吸附氢化物脱附过程的最重要因素。在碱性介质中形成辉辉（shbh3）的速率控制步骤是阴极表面的shbh3解吸过程。研究了电解条件和干扰离子对EcHG的影响。在优化条件下，水溶液中As（III）和Sb（III）的检出限（3σ）分别为0.37μgL−1和0.32μgL−1；20μgL−1As和Sb的相对标准偏差（n=6）分别为2.8%和3.1%。该方法已应用于长江水中砷、锑不同氧化态的测定。
In this study, we present a method for the detection of As and Sb using electrochemical hydride generation (EcHG) under alkaline conditions. Compared to the traditional acid mode, the alkaline mode has better interference tolerance. Moreover, As(III) and Sb(III) could be directly detected by the proposed method. Completely inorganic As and Sb could be detected with a pre-reduction step. The electrolytic reduction process of Sb is studied in detail by cyclic voltammetry. The results indicate that the location for the introduction of carrier gas is the most important factor that influences the desorption process of adsorbed hydrides. The rate-controlling step for stibine (SbH3) formation in an alkaline medium is the desorption process of SbH3from the cathode surface. The effects of electrolytic conditions and interference ions on EcHG have been studied. Under the optimized conditions, the detection limits (3σ) of As(III) and Sb(III) in aqueous solutions are 0.37μgL−1and 0.32μgL−1, respectively; relative standard deviations (n=6) of 2.8% and 3.1% for 20μgL−1As and Sb are obtained. This method has been applied in the determination of different oxidation states of As and Sb in Yangtze River water.