Abstract:

A novel system for determination Sb by electrochemical hydride generation in phosphate buffer solution was studied. It was found that the use of neutral phosphate buffer solution could markedly increase the fluorescence intensity of Sb (III) and suppress totally signal of Sb (V). The analysis of Sb valence could be carried out in buffer solution. Moreover, it has some merits like reducing self-erodible effect of cathode materials, prolonging the lifetime of cell and increseing stability of signal. The traditional thin-type cell was improved and a new cell with screw-thread for easy dismounting, named disk type cell, was developed. Assembly time of the disk cell is only about 1 min, and the time of analytical process is shortened largely compared with the other cells because the time of assembling eight or ten screws is about 20 minutes. Secondly, sealing performance of this cell is better than the traditional electrolytic cell, which is held together with several screws or epoxy resin. The effects of the electrolytic conditions and interferences ion on the EcHG have been studied. The detection limits (3? of 0.038 礸/L Sb (III) in aqueous solutions were obtained, respectively. The precisions (n=11) for 20 礸/L Sb(III) was 3.9%,. This system has been applied satisfactorily to the determination of Sb in environment samples.

Key words: Electrochemical hydride generation, electrolyte, phosphate buffer solution, antimony