碳纳米管修饰碳糊电极吸附溶出伏安法测定铜

Determination of Trace Copper by Adsorptive Stripping Voltammetry Using a Multi-wall Carbon Nanotube Modified Carbon Paste Electrode

制备了羧基化碳纳米管修饰碳糊电极（MWCNT/CPE）,并研究了Cu（Ⅱ）-SPAPT络合物在该电极上的吸附伏安行为,建立了一种测定痕量铜的新方法。采用二阶导数线性扫描溶出伏安法进行分析。结果表明：在0.1 mol/L的HAc-NaAc（pH=4.0）中,于-400 mV处搅拌富集一定时间,从-400~600 mV范围内以250 mV/s的扫描速度线性扫描,络合物吸附在MWCNT/CPE表面,于66 mV（vs.SCE）处产生一灵敏的阳极溶出峰,其峰电流与Cu（Ⅱ）浓度在4×10-11mol/L-8×10-9mol/L和8×10-9mol/L-1×10-7mol/L范围内分两段呈良好的线性关系,检出限（S/N=3）为2.2×10-11mol/L（富集时间240 s）。同时,探讨了电极反应机理。该方法操作简便、灵敏度高,应用于人发中铜含量的测定,结果满意。

A multi-wall carbon nanotube modified carbon paste electrode was prepared and the adsorptive stripping voltammetric behavior of copper at the modified electrode was investigated,a new method for the determination of trace copper was described.It was found that in HAc-NaAc buffer solution（pH4.0）,An coordination compound was formed by 1-（4-sulfo-phenyl）-3-[4-（phenylazo）-phenyl]-triazene（SPAPT） with copper Ⅱ,it was accumulated and reduced on the surface of the modified electrode at-400 mV.When scanning linearly was from-400 mV to 600 mV at a scan rate of 250 mV/ s,the sensitive anodic stripping peak appeared at 66 mV（vs.SCE）.The linear range was found to be 4×10-11mol/L-8×10-9mol / L and 8×10-9mol/L-1×10-7mol/L.The detection limit was 2.2×10-11mol/L（S/ N =3） for 240 s accumulation.The proposed method was satisfactorily applied to the determination of t race copper in human hair.