Electrooxidation of pyridoxal (PL) on a polycrystalline gold electrode in alkaline solutions

The electrooxidation of pyridoxal (PL) on a polycrystalline gold electrode is studied by cyclic voltammetry in alkaline media. Two oxidation peaks, A and B, are obtained in the positive scan within the potential range of the double-layer region. The behavior observed allows to propose an oxidation mechanism where the anion hemiacetal (ha−) and hemiacetal (ha) are the electroactive species for peaks A and B, respectively. The oxidation product for both peaks is pyridoxic acid, in agreement with the analysis of the products obtained after controlled potential electrolysis.