| Since Wang et al introduced the bismuth film electrodes (BiFEs) in electrochemical stripping voltammetry analysis in 2000, these new electrodes have been attracted the attention of many electroanalytical researchers because of their remarkable characteristics of small toxicity, simple preparation and good electrochemical properties, and the traditional mercury electrode in electroanalytical chemistry fast replaced by bismuth film electrode. Furthermore, the sensitivity and selectivity of the BiFFs could be further improved by depositing on the polymeric membrane. Moreover, stannum and bismuth are in catercorner position at periodic table of chemical elements, so the electrochemical characteristics of stannum is similar to that of bismuth. In addition, stannum is a more "green" element, with very low toxicity and cost, so it is important to investigate the preparation and application of a novel environmentally friendly stannum film electrode. This paper continued to investigate the application and preparation of bismuth film and stannum film electrode for analysis of metal ions on a series of substrates materials. The main research contents are as follows:1. Fabrication of stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode and its application for measurement of cadmium (Ⅱ)A new method for a trace analysis of metal cadmium ion has been developed on the stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode. This new electrode was prepared by in situ depositing stannum, bismuth and target metal on the poly(p-aminobenzene sulfonic acid)(p-ABSA) coated glassy carbon electrode. Some key factors including the pH of measure solution, the proper proportion between Bi(Ⅲ) and Sn(Ⅱ), the deposition time and the deposition potential have been studied and optimized. Compared with the traditional bismuth film electrode, the stannum/bismuth/poly(p-ABSA) film electrode displayed higher stripping current response. In addition, it has the advantages of better stability and less toxicity. Under the optimum conditions, the linear calibration graph for Cd(II) in the concentration range of 0.5 to 55.0μg L-1 was obtained and the detection limit was 0.32μg L-1. The method was applied to the analysis of cadmium ion in tap water sample with satisfactory results.2. Fabrication of bismuth/poly(aniline) film modified electrode and its application for measurement of cobalt (Ⅱ)A sensitive method was developed for the determination of Co(II) by square wave adsorpting stripping voltammetric using bismuth coated poly(aniline) modified film electrode (Bi/poly(aniline)FE) in ammonia buffer solution (pH 8.0). The electrochemical response of cobalt was apparently improved by poly(aniline) due to the enhanced the surface absorption sites of Co-DMG complexs. In comparison with the bismuth film electrode, the Bi/poly(aniline)FE proved to be more sensitive, experimental parameters including the concentrations of DMG, pH of measure solution, adsorption potential and adsorption time were investigated and optimized. Under optimized conditions, the peak current was proportional to the concentration of Co(II) in the range of 1.0-120.0μg L-1 with the detection limit of 0.84μg L-1. Application of the new electrode for the determination of cobalt in river water samples gave good results.3. Study on the bismuth film modified doped sodium montmorillonite carbon paste electrode and its application for measurement of lead (Ⅱ)A simple and reliable electrochemical method for the determination of lead using a bismuth film modified doped sodium montmorillonite carbon paste electrode (Bi/Na-MM/CPE) was described. The new electrode significantly enhanced the sensitivity of determination for Pb(II) and exhibited superior performance in comparison with the bare carbon paste electrode (CPE), bismuth film modified carbon paste electrode (Bi/CPE), and Na-MM modified carbon paste electrode (Na-MM/CPE). Many parameters such as the composition of the paste, pH of measure solution, the Bi(Ⅲ) concentration, deposition time and deposition potential that influenced the response of lead were investigated. Combination with square-wave anodic stripping voltammetry, the new electrode displayed excellent linear behavior in the examined concentration range from 0.3 to 85.0μg L-1 Pb(Ⅱ) (r=0.996) with detection limit of 0.28μg L-1. The electroanalytical performance of Bi/Na-MM/CPE for lead was successfully tested in tap water and river water samples.4. Study on the stannum film modified carbon paste electrode and its application for measurement of copper (Ⅱ) A selective and sensitive method was developed for the determination of Cu(Ⅱ) by square wave anodic stripping voltammetric using stannum film modified carbon paste electrodes (SnF-CPEs) in acetate buffer of solution pH 3.6. The electrochemical response of copper was apparently improved by stannum due to the enhanced accumulation of copper at the electrode surface. In comparison with the bare carbon paste electrode, the SnF-CPE was proved to be more sensitive, in addition, the stripping peaks of stannum and copper do not overlap with each other. The experimental parameters including the concentrations of Sn(II), pH of measure solution, deposition potential and deposition time were investigated and optimized. Under optimized conditions, the peak current was proportional to the concentration of Cu(Ⅱ) in the range of 1.0-75.0μg L-1 (r=0.998) with the detection limit of 0.50μg L-1. Application of the new electrode for the determination of copper in river water samples gave good results.
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