Spectroscopic confirmation of electrocatalytic behavior of amperometric carbohydrate detection on copper electrode

Working electrodes made of copper have been proved applicable in voltammetric analysis of different substances like sugars, amino acids playing important role in living organisms. Advantageously, copper electrodes are free of electrode passivation by the reaction product of electrochemical oxidation in cases, when the fouling of platinum- or carbon based conventional working electrodes is common.Suggestions, experimentally more or less supported, have been published about the electrode reaction involved for explanation. To obtain further hints about electrode process extensive controlled potential electrolysis of certain monosaccharides have been carried out in basic media and the reaction media have been analyzed with atomic absorption spectrometry, voltammetry and ion chromatography. Formate ions were detected as the major product, and their concentration was measured, while only low concentration of copper could be detected. From the charge passed and the concentration changes the number of electrons exchanged could be determined. The results are direct proof of the electrocatalytic nature of the electrode process and they contradict the considerable involvement of electrode corrosion.