Electrocatalytic Oxidation and Determination of Nitrite at Multi-Walled Carbon Nanotubes Modified Electrode

Abstract

Electrocatalytic oxidation of nitrite at multi-walled carbon nanotubes (MWCNTs) modified electrode was investigated by using voltammetric techniques. The kinetic parameters such as diffusion coefficient (D), standard heterogeneous rate constant (k_s) and catalytic constant (k_h) were studied by chronocoulometry and chronoamperometry. The corresponding parameters for D, k_s, and k_h were caculated to be 3.56×10^-5 cm² s^-1, 6.29×10^-3 cm s^-1 and 7.02×10² M^-1 s^-1, respectively. The modified electrode was used for the determination of nitrite with a concentration range of 0.5 to 36 μM and a detection limit of 0.08 μM. The proposed method was successfully applied for the determination of nitrite in real samples of tap water and juice of pickled garlic.