Catalytic Reduction of Bisulfite by Myoglobin/Surfactant Films

Abstract

The voltammetry of bisulfite at a film formed with myoglobin was studied in aqueous solutions. A broad wave was observed for the reduction of bisulfite. Using controlled potential electrolysis, the reduction at potentials positive of the FeII/FeI wave formed dithionite exclusively. As the potential approached the region for the FeII/FeI reduction, bisulfite was reduced primarily to HS−. Even at the negative potentials, some dithionite was still formed, which could then be electrochemically reduced to thiosulfate. Analysis of the formation of HS−, dithionite and thiosulfate during the electrolysis was consistent with the parallel formation of HS− and dithionite, the latter of which was reduced to thiosulfate. Thiosulfate was verified by chemical analysis of the products from controlled potential electrolysis of the solution, and dithionite was observed spectroscopically using spectroelectro−chemistry.