将羧基化多壁碳纳米管分散在Nafion溶液中并滴涂在玻碳电极表面,制备了羧基化多壁碳纳米管-Nafion修饰电极(MWCNT′s-Nafion/GCE)。应用此修饰电极测定镉时,将试液在pH 4.8乙酸-乙酸钠缓冲溶液中,于-1.1 V处预还原富集350 s,然后在-1.2~-0.4 V范围内扫描,使镉离子从修饰电极上溶出,实现了镉离子的差分脉冲阳极伏安法测定,在-0.84 V可得镉离子的氧化峰电位,镉的质量浓度在5~100 μg·L-1范围内与其峰电流呈线性关系,方法的检出限(3S/N)为2.54 μg·L-1。方法用于测定水样中的痕量镉,与电感耦合等离子体质谱法测定值相一致。

Carboxylated multi-wall carbon nano-tubes (MWCNT′s) was dispersed in Nafion solution, and dropped on the surface of glassy carbon electrode (GCE) to prepare MWCNT′s-Nafion modified GCE (MWCNT′s-Nafion/GCE). In the determination of Cd2+-ion, the test solution in a NaOAc-HOAc buffer solution of pH 4.8 was pre-reduced and enriched for 350 s at -1.1 V, Cd2+-ion was then stripped from the electrode by scanning in the range from -1.2 V to -0.4 V and determined by differential pulse anodic stripping voltammetry. Oxidation peak potential of Cd2+-ion was observed at -0.84 V, at where linear relationship between values of peak current of Cd2+-ion and its concentration was obtained in the range of 5-100 μg·L-1, with detection limit (3S/N) of 2.54 μg·L-1. The proposed method has been used in the determination of cadmium in water sample, giving results obtained in consistency with those obtained by ICP-MS.