A kinetic study of D-glucose oxidation by bromine in aqueous solutions

摘要

The kinetics of the oxidation of D-glucose to D-gluconic acid by bromine in aqueous solution were studied using poten-tiometric techniques and theoretical considerations of complex bromine-bromide-pH equilibria.The pH has a strong influence on reaction rate.At pH < 8 the reaction is very slow,while in the pH range pH 8-9.5 the reaction is sufficiently fast and seems optimal for the reaction.The proposed active species at that pH region is hypobromous acid.At pH > 9.5,the reaction is further accelerated due to the formation of hypobromite.The proposed kinetics expression for gluconic acid formation,based on the determined kinetic parameters at pH 9.24,is of the form dc(GA)/dt = 160c~2(G)c_0(HOBr)c~0(H~+)c~0(Br)