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

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

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。

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 Bi^3＋ -ion, the test solution in 0. 1mol·L^-1 HC1 was pretreated by pre-enrichment for 120 s at - 500 mV, to have the Bi^3＋- 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 vohammetry 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 Bia＋ ion and its concentration was obtained in the range of 1.0X10 ^-9-4. 0× 10 ^-7mol·L^-1. Detection limit （3S/N） of the method found was 3.0×10^-10 mol·L^-1.