多壁碳纳米管修饰电极阳极溶出伏安法测定痕量银

来源期刊：冶金分析2011年第5期

论文作者：明亮 习霞

文章页码：45 - 48

关键词：碳纳米管； 化学修饰电极； 溶出伏安法； 银

Key words：carbon nanotube； chemically modified electrode； stripping voltammetry； silver

摘    要：利用多壁碳纳米管修饰玻碳电极,通过优化支持电解质及pH值、修饰剂用量、富集电位及时间等测定条件,建立了测定痕量银的线性扫描阳极溶出伏安分析法。在pH 4.0的NaAc-HAc缓冲液中,-0.10 V电位下富集5 min后,于0.46 V处出现一灵敏度高、峰形较好的银阳极溶出峰,溶出峰电流与Ag+浓度在3.0×10^-8～5.0×10^-5 mol/L的范围呈良好的线性关系,Ag⁺的检出限为1.0×10^-8 mol/L,在选定的最佳实验条件下一些常见的金属离子几乎不干扰银的测定。该法用于环境水样及锌合金样品中痕量银的测定,平均回收率在96%～103%之间。

Abstract: A linear sweep stripping voltammetry for the determination of trace silver was developed by using multi-wall carbon nanotube (MWCNT) modified glassy carbon electrode (GCE) and optimizing the determination conditions such as supporting electrolyte and pH,the amount of modifier,the accumulation potential and time.In NaAc-HAc buffer solution at pH 4.0,an anodic stripping peak with high sensitivity and good shape appeared at 0.46 V after accumulation at-0.10 V for 5 min.The stripping peak current varied linearly with the concentration of Ag+ in the range of 3.0×10^-8 to 5.0×10^-5 mol/L.The detection limit of Ag+ was 1.0×10^-8 mol/L.Under the optimized experimental conditions,some common metal ions did not interfere in the determination of silver.The proposed method was applied to the determination of trace silver in environmental water and zinc alloy samples.The average recoveries for addition standard were between 96% and 103%.