ABSTRACT
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 μmol/L with a detection limit of 0 . 02 μmol/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%.