A colorimetric micro-method for the determination of glucose

Abstract

A colorimetric micro-method for detn. of glucose was descr. This method is based on the observation that a bluish-pink color develops when one vol. of a dilute soln. of glucose is heated with 3 vols. of 96% (wt/wt) sulfuric acid; the intensity of the pink color is proportional to the concn. of glucose. The glucose is dehydrated in hot sulfuric acid to 5-hydroxymethylfurfural, which reacts with a compound intermediate between glucose and hydroxymethylfurfural to produce the pink color. For practical purposes, this reaction appears to be specific for glucose, fructose and saccharides containing these 2 hexoses. The true glucose content of blood can be detd. by this simple method after the blood has been deproteinized with a trichloroacetic acid soln. containing silver sulfate.