基于羧基化碳纳米管修饰电极伏安法同时测定痕量铟和铝

Simultaneous Determination of Indium and Aluminum by Voltammetry Based on Carboxylic Carbon Nanotubes Modified Electrode

基于羧基化多壁碳纳米管(c-MWCNT),制备了可同时测定In3+和Al3+的新型碳材料修饰电极。利用循环伏安法(CV)和交流阻抗法(EIS)对此修饰电极进行了表征,用线性扫描伏安法(LSV)研究了In3+与Al3+共存于修饰电极上的电化学行为。与裸玻碳电极相比,新型碳材料修饰电极的电化学活性得到很大提高;In3+与Al3+无需电分离即可在此电极上实现同时被检测;1.0×10-9～2.5×10-8mol/L In3+和5.0×10-9～5.0×10-8mol/L Al3+与其峰电流差呈良好线性关系,其相关系数分别为0.9943和0.9975;同一个修饰电极连续测定6次,In3+和Al3+的RSD分别为1.5%和1.7%,说明其稳定性较好;用于金属冶炼厂附近湘江水样中In3+和Al3+含量的测定,回收率分别在97.0%～102.0%和95.0%～101.8%之间。

A novel carbon materials modified electrode was prepared by carboxylic multi-walled carbon nanotubes（c-MWCNT）,and this modified electrode can detect two kinds of trivalent metal ions（In3＋,Al3＋） simultaneously.The modified electrode was characterized by cyclic voltammetry（CV） and electrochemical impedance spectrum（EIS）.The electrochemical behaviors of In3＋ and Al3＋ at the modified electrodes were investigated by linear sweep voltammetry（LSV）.The experimental results showed the electrochemical activities of the new carbon material modified electrode were improved greatly compared with the bare glassy carbon electrode.In3＋ and Al3＋ can be detected simultaneously without electric separation.The concentrations of two kinds of metal ions in the range of 1.0×10-9-2.5×10-8 mol/L and 5×10-9-5.0×10-8 mol/L presented excellent linear relationships to their peak currents,and their correlation coefficients were 0.994 and 0.997 respectively.A modified electrode was used to detect In3＋ and Al3＋ for 6 times,and RSD of the detection results was 1.5% and 1.7% respectively.The modified electrode exhibited good stability and has been used to detect indium and aluminum concentrations in Xiangjiang river samples which is near to metallurgical works.The recoveries were 97.0%-102.0% and 95.0%-101.8%.