羧基化多壁碳纳米管修饰碳糊电极用于溶出伏安法测定铋(Ⅲ)量

将羧基化的多壁碳纳米管滴涂在碳糊电极表面上,应用羧基化的多壁碳纳米管修饰碳糊电极(MWCNT-COOH/CPE)测定铋(Ⅲ)时,将试液在0.1mol.L-1盐酸溶液中在-500mV处预富集120s,使铋(Ⅲ)与1-(4-磺酸基苯基)-3-4-(苯基偶氮)-苯基]-三氮烯(SPAPT)生成络合物,然后在-500～500mV范围内扫描,使络合物中的铋(Ⅲ)从电极上溶出,实现了铋离子的溶出伏安法测定。在-32mV处可得铋离子的氧化峰电位,其峰电流值与铋(Ⅲ)浓度在1.0×10-9～4.0×10-7 mol.L-1范围内呈线性关系,检出限(3S/N)为3.0×10-10 mol.L-1。

Stripping Valtammetric Determination of Bismuth(Ⅲ) with Carboxylated Multi-walled Carbon Nanotubes Modified Carbon Paste Electrode

A carboxylated multi-wall carbon nanotubes(MWCNT-COOH) modified carbon paste electrode(CPE) was prepared by doping MWCNT-COOH on the surface of CPE.In the determination of Bi3+-ion,the test solution in 0.1 mol·L-1 HCl was pretreated by pre-enrichment for 120 s at-500 mV,to have the Bi3+-ion complexed with 1-(4-sulfo-phenyl)-3-4-(phenylazo)-phenyl]-triazene(SPAPT).Bismuth ion in the complex was then stripped from the electrode by stripping voltammetry by scanning in the range from-500 to 500 mV,and the oxidation peak potential of bismuth ion was observed at-32 mV,where linear relationship between values of peak current of Bi3+-ion and its concentration was obtained in the range of 1.0×10-9-4.0× 10-7mol·L-1.Detection limit(3S/N) of the method found was 3.0×10-10mol·L-1.