Determination of the different oxidation states of As and Sb by a new electrochemical hydride generator coupled with atomic fluorescence spectrometry.
A novel disk electrochemical hydride generator has been developed for the determination of As and Sb. Compared with the traditional thin-layer cell, the disk cell combined the advantages of quick assembly and easy operation. This electrochemical system for hydride generation in neutral buffer solutions has been studied for analytical usefulness in coupling with atomic fluorescence spectrometry. It was found that the use of neutral phosphate buffer solution could markedly increase the fluorescence intensity of As(III) and Sb(III) and reduce the impact of cathode erosion on the stability of signal intensity. At the same time, the fluorescence intensity of As(V) and Sb(V) were almost suppressed totally. The detection limits (3 sigma) of 0.031 microgL(-1) As(III) and 0.026 microgL(-1) Sb(III) in aqueous solutions were obtained, respectively. The precisions (n=11) for 20 microgL(-1) As(III) and Sb(III) were 2.0% and 2.7%, respectively. The method was successfully applied for determination of different oxidation states of As and Sb in environmental samples.
Zhang
Wang-bing
WB
Department of Applied chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. zhangwb@ahut.edu.cn
Yang
Xin-an
XA