电化学氢化物发生-原子荧光法测定环境样品中的Se(Ⅳ)和Se(Ⅵ)

Determination of Se(Ⅳ) and Se(Ⅵ) in environmental samples by atomic fluorescence spectrometry with electrolytic hydride generation

设计了一种新的电化学氢化物发生装置,用于测定不同价态的硒。通过对传统的平板电解池的改进,设计了全新的圆盘电解池并采用螺纹密封的方式,极大地缩短了电解池的装配时间,提高了电解池的使用寿命和密封性能。结合热水浴在线还原技术,将Se(Ⅵ)在高浓度HCl介质中120 s内还原成Se(Ⅳ),通过电化学氢化物发生技术生成氢化物,成功的进行硒的在线价态分析。对各种实验参数进行了详细的研究,Se(Ⅳ)和Se(Ⅵ)的相对标准偏差分别为2.6%和3.1%(n=11);Se(Ⅳ)和总硒的检出限分别为0.32和0.27μg/L(3σ)。

A new electrochemical generator was designed to detect different oxidation states of Se. The traditional thin-layer cell was improved. The problem of leakage of cell, usually existed in the traditional sealing method by screw, was resolved by the utilization of new sealing method with screw thread. The hydride of Se （Ⅵ） by electrolychemical hydride generation was formed after an on-line heating water reduction process. The proposed method was successfully applied to determination of different oxidation states of Se coupled with atomic fluorescence spectrometry. The precisions for 11 replicate measurements of 40μg/L Se（Ⅳ） and Se（Ⅵ） were 2.6 % and 3.1%. The detection limits （3σ） of Se（Ⅳ） and total Se in aqueous solution was 0.32 μg/L and 0.2μg/L, respectively.