Electrocatalytic Oxidation of Trimethoprim at Multi-wall Carbon Nanotubes-Nafion Modified Glassy Carbon Electrode and Its Electrochemical Determination
Electrochemical behaviors,electrochemical kinetics and electrochemical determination of trimethoprim(TMP) at multi-wall carbon nanotubes-Nafion modified glassy carbon electrode(MWCNTs-Nafion/GCE) were investigated by cyclic voltammetry(CV),chronocoulometry(CC),chronoamperometry(CA),linear scan voltammetry(LSV) and amperometric i-t curve. The experimental results showed that the direct electrochemical oxidation of TMP is sluggish on GCE,but the oxidation peak current of TMP increases significantly at MWCNTs-Nafion/GCE in comparison with that at bare GCE,which indicates that MWCNTs-Nafion/GCE can catalyze the electrochemical oxidation of TMP very well. It has also been done that the research on the influence of the experimental conditions on TMP electrochemical behaviors. The results showed that the electrode reaction process is a diffusion-limited. At MWCNTs-Nafion/GCE,the oxidation peak current is proportional to the concentration of TMP over the range from 5.0×10-6 to 1.0×10-3 mol/L. The detection limit is 6.6×10-7 mol/L. The relative standard deviation is between 0.8% and 1.7% and the recovery is 98.1%-101.1%. This MWCNTs-Nafion/GCE method has been applied in the determination of TMP in tablet samples with the satisfied results.