聚铬黑T修饰电极检测亚硝酸盐的研究

Determination of nitrite on a poly(eriochrome black T)modified electrode

利用电化学聚合法将铬黑T修饰到玻碳电极表面,制得聚铬黑T修饰电极。该修饰电极对亚硝酸盐的电化学氧化具有明显的催化作用,这种催化作用主要是由于聚铬黑T薄膜与带负电荷的亚硝酸盐离子的静电相互作用,导致亚硝酸盐离子富集在电极表面/溶液界面,显著增强了亚硝酸盐的氧化电流。电子传输系数α为0.735。选用0.85V作为工作电压,对亚硝酸盐进行安培检测,在0.05μmol/L～1.0 mmol/L和1.0～20.0 mmol/L两个浓度范围内呈现良好的线性关系,检测限达到0.01μmol/L。且该修饰电极有良好的重现性和稳定性。将该修饰电极用于泡菜中亚硝酸盐的测定,获得了满意的结果。

A poly（ eriochrome black T）modified electrode was fabricated by electrochemical polymerization of eriochrome black T on glassy carbon electrode. Due to the electrostatic interaction between the negatively-charged nitrite ions and poly （ eriochrome black T） film,the poly（ eriochrome black T）modified electrode exhibited enhanced electrocatalytic properties towards the oxidation of ni- trite, observing an improved peak current. The electron transfer coefficient is 0. 735. The poly （ eriochrome black T） modified elec- trode exhibited fast response towards nitrite with a detection limit of 0. 01 μmol/L and linear range of 0.05 μmol/L - 1.0mmol/L and 1.0 - 20. 0mmol/L by amperometric detection techniques. Moreover, the modified electrode exhibited good repeatability and long-time stability. The developed modified electrode was also successfully applied to the determination of nitrite in salted cabbage sample with recoveries of 97.4 - 101.8%.