Determination of nitrite with a nano-gold modified glassy carbon electrode by cyclic voltammetry

摘要

The fabrication and electrochemical characteristics of nano-gold modified glassy carbon (NG/GC) electrode were investigated. The modified electrode showed an obvious electro-catalytic activity for the oxidation of nitrite at 0.850V versus the Ag/AgCl electrode in 0.05 mol L~(-1) H_2SO_4 solution. Some electrochemical parameters, such as the diffusion coefficient, D, electron transfer number, n, and rate constant, k_s, were calculated. The peak current was proportional to the concentration of nitrite in the range of 5.0 x 10~(-6) to 5.0 x 10~(-4) mol L~(-1) for the cyclic voltammogram method with the detection limit of 5.0 x 10~(-7) mol L~(-1). The possible reaction mechanism has also been discussed. The NG/GC electrode has a high stability and can be applied to the determination of nitrite in rain water with simplicity, rapidity, and accurate results.