2,3,5-Triphenyl-2H-tetrazolium chloride as a reagent for the determination of sugar mixtures by a differential reaction-rate technique

Abstract

The rates of reaction of 2,3,5-triphenyl-2H-tetrazolium chloride with the more common hexoses (glucose, fructose, mannose, sorbose and galactose) and pentoses (xylose and ribose) have been studied. Under certain conditions, over a limited range of reaction, the extent of the reaction is directly proportional to the time of reaction (a "pseudo zero-order" reaction). Also, the rates of reaction of the sugars are quite different in most cases. Thus, the behaviour of this reagent is quite satisfactory for the determination of binary mixtures of most of the sugars tested, by a simple differential rate technique developed for "zero-order" competitive reactions. The rates of reaction of 2,3,5-triphenyl-2H-tetrazolium chloride with ascorbic acid, creatinine and glutathione, often found in blood serum, which interfere with most blood serum sugar analysis methods, have also been examined to determine if they would interfere with the determination. Glutathione and creatinine do not react with the reagent and do not interfere with the analysis of sugar mixtures. Ascorbic acid, however, reacts rapidly, and as little as 1-2% leads to error in the sugar-mixture determination.