多壁碳纳米管修饰乙炔炭黑电极测定碘  

Determination of Iodine with Multi-Walled Carbon Nanotubes Modified Acetylene Black Electrode

作　　者：邓培红[1] 费俊杰[2] 匡云飞[1] 

机构地区：[1]衡阳师范学院化学与材料科学系,衡阳421008 [2]湘潭大学化学学院,湘潭

出　　处：《应用化学》2009年第7期875-877,共3页Chinese Journal of Applied Chemistry

基　　金：衡阳市科学技术局(2007KJ001);衡阳师范学院科学基金(07A19)资助项目

摘　　要：以多壁碳纳米管修饰乙炔炭黑电极为工作电极,研究了碘离子在该修饰电极上的伏安分析特性,讨论了支持电解质种类、酸度等因素对碘离子氧化峰电流的影响,获得了最佳的实验条件。在0.4mol/LKH2PO4缓冲液(pH=4.0)中,从200mV以200mV/s的速率正向扫描至1200mV,碘离子在570mV处出现一灵敏的氧化峰,峰电流比未修饰电极增大约3倍。采用二阶导数线性扫描伏安法进行定量分析,峰电流与碘离子的浓度在2.0×10-6～1.0×10-3mol/L范围内呈良好的线性关系,检出限为8.0×10-7mol/L。方法用于食盐中碘含量的测定,相对标准偏差为1.2%～1.6%,回收率为97.4%～103%。A multi-wall carbon nanotubes modified acetylene black electrode was prepared and the voltammetric characteristics of iodine ions on the modified electrode was studied. The effects of the type and acidity of electrolytes on the oxidation peak current of iodine ions were also studied to acquire optimum conditions. In 0. 4 moL/L KH2PO4 solution（ pH =4.0） , when scanning linearly from 200 mY to 1 200 mV at a scan rate of 200 mV/s, a sensitive oxidation peak appeared at 570 mV （vs. SCE ）. The peak current of the modified electrode raised around three fold than that of the unmodified electrode. By means of the second derivative linear sweep technique, good linearity was obtained between the oxidation peak current and the concentration of iodine ions in a range of 2.0 ×10^-6 - 1.0 × 10^-3 mol/L, and the detection limit reached 8.0 × 10^-7 mol/L. This method was successfully applied to the determination of iodine in edible salt. The relative standard deviation was between 1.2% - 1.6% , and the relative error was between 97.4% - 103%.

关 键 词：化学修饰电极 多壁碳纳米管 碘离子 伏安法 

分 类 号：O657[理学—分析化学]