Some Interferences in the Alkaline Copper Method of Reducing Sugar Analysis

Abstract

It has been found that boric acid and chloride ions suppress the reducing power of glucose and maltose. While boric acid does not affect the linearity of absorbance versus concentration curves, nonlinearities may occur if chloride is present in the solution to be analyzed. It has also been found that the proper upper limit of the alkaline copper method is 175 μg/ml for glucose, as opposed to the commonly adopted value of 300 μg/ml.