Electrochemical Behavior and Determination of Pyridoxine Hydrochloride at Graphene-Carbon Nanotubes/Poly (nicotinic acid) Modified Electrode

Graphene (GN) and multiwalled carbon nanotubes (MWCNT) composites were coated on glassy carbon electrode (GCE) and then poly (nicotinic acid) (PNA) was electrodeposited on the modified electrode. The electrochemical behavior of pyridoxine hydrochloride (VB6) was investigated at the modified electrode by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Results showed the oxidation current of VB6 at the GN-MWCNT/PNA/GCE was obviously larger than that at GCE, PNA/GCE and GN/MWCNT/GCE. The oxidation process of VB6 was an irreversible diffusion-controlled process involving one electron and two protons. The liner range between the peak current intensity of DPV and the concentration of VB6 was 0.05-200 mu mol/L with a detection limit of 0.02 mu mol/L (S/N = 3). The modified electrode showed a good reproducibility with a relative standard deviation of 3. 1% (n = 8). The proposed method was applied to the analysis of vitamin B6 in vitamin B6 tablets and compound vitamin B tablets with recoveries between 96.1% - 104.5%.