SELF-DRIVEN COULOMETRY OF ETHANOL, D-GLUCOSE AND D-FRUCTOSE USING UBIQUINONE-DEPENDENT DEHYDROGENASE REACTIONS

Self-driven coulometry has been applied to the determination of the su bstrates of ubiquinone-dependent dehydrogenase, and the optimum condit ions for the absolute determinations of the reduced ubiquinone, ethano l, D-glucose and D-fructose were obtained. The reduced ubiquinone was oxidized directly at the working carbon felt electrode of the coulomet ric cell with the counter carbon felt electrode impregnated with hexac yanoferrate(III) ion counter solution, driven by the electromotive for ce generated between both electrodes. Ethanol, D-glucose and D-fructos e are oxidized by ubiquinone, catalyzed by dehydrogenases and each deh ydrogenase reaction of these substrates proceeded completely prior to the addition of the sample on the carbon felt electrode surface. Conse quently, all of these analytes have been determined with nearly 100% d ischarging efficiencies, and self-driven coulometry coupled with ubiqu inone-dependent dehydrogenase reactions has been estimated as a conven ient analytical method for the determination of the biochemical substr ates.