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

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 (ks) and catalytic constant (kh) were studied by chronocoulometry and chronoamperometry. The corresponding parameters for D, ks, and kh 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.