Simultaneous EQCM and fluorescence detection of adsorption/desorption and oxidation for pyridoxol in aqueous KOH on a gold electrode

A simultaneous EQCM–fluorescence method has been proposed as a novel and informative tool for the study of the adsorption/desorption and oxidation for vitamin B6 (pyridoxol) at a polycrystalline Au electrode in aqueous KOH. The oxidation of pyridoxol was irreversible and accompanied by a strong electrogenerated fluorescence emission peaking at 443 nm when excited at 360 nm. The adsorption and desorption of the oxidation product were found in the double layer region and were discussed by analyzing the simultaneous fluorescence and EQCM data. In addition, the voltammetrically electrogenerated fluorescence is proposed as a new and sensitive method for assay of pyridoxol with satisfactory results.