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

In the present work, the electrochemical oxidation of nitrite on carbon ceramic electrode (CCE) modified with multi-walled carbon nanotubes (MWCNTs) was investigated. The modified electrode exhibited catalytic activity toward the electrooxidation of nitrite. Experimental parameters such as solution pH, scan rate, concentration of nitrite and nanotubes amount were studied. It was shown nitrite can be determined by differential pulse voltammetry (DPV) and hydrodynamic amperometry (HA) using the modified electrode. Under the optimized conditions the calibration plots are linear in the concentration ranges of 15-220 and 50-3000 mu M with limit of detections of 4.74 and 35.8 mu M for DPV and HA, respectively. The modified electrode was successfully applied for analysis of nitrite in spinach sample. The results were favorably compared to those obtained by UV-Visible spectrophotometric method. The results of the analysis suggest that the proposed method has promise for the routine determination of nitrite in the examined products.