用稀土(镱)杂多酸盐/多壁碳纳米管修饰的玻碳电极测定亚硝酸根

Determination of Nitrite with the Modified Electrode of YbHS/MWCNT's/GCE

将多壁碳纳米管分散在镱(Ⅲ)杂多酸盐溶液中,将上述获得的悬浊液滴涂在玻碳电极表面,制备了镱(Ⅲ)杂多酸盐/多壁碳纳米管修饰的玻碳电极(YbHS-MWCNT′s/GCE)。采用交流阻抗法对电极表面的性能进行了表征,采用循环伏安法对其电化学性能进行研究。研究发现,亚硝酸根在该修饰电极上出现一个氧化峰,氧化峰电位在-0.45V处,提出了用循环伏安法测定亚硝酸根的方法。亚硝酸根的浓度在5.0×10-6～1.0×10-4mol.L-1范围内,氧化峰电流与其浓度呈线性关系。修饰电极用于环境水样中亚硝酸根离子的测定,回收率在97.2%～98.0%之间。

The modified electrode was prepared by dropping a suspension of multiwall nanoearbon tubes （MWCNT＇s） in a solution of ytterbium salt of heteropoly acid （YbHS） onto the surface of glassy carbon electrode （GCE）, which is abbreviated as YbHS/MWCNT＇ s/GCE. The surface property of the modified electrodes was characterized by AC impedance method, and its electrochemical property was studied by cyclic voltammetry. It was found that nitrite ion showed an oxidation peak at the potential of --0.45 V. Based on these findings, a selective method for determination of nitrite by cyclic voltammetry was proposed. Linear relationship between values of peak current and concentration of NO2- was ranged from5.0×10-6-1.0×10-4mol·L-1. The proposed method was used in the analysis of environmental water samples, giving values of recovery in the range of 97, 2%-98. 0%.