Studies on the Determination of Serum Glucose with o-Toluidine Using No Glacial Acetic Acid (II)

Abstract

The method of determination of serum glucose with o-toluidine using glacial acetic acid medium has been generally adopted in clinical laboratories because of its high sensitivity and reproducibility. However, the irritant vapor of glacial acetic acid is not desirable. An attempt was made to evaluate the efficacy of a mexture of glycollic acid and propylene glycol used instead of glacial acetic acid. This mixture is colorless, stable for at least several months in a refrigerator, and not irritant. The reagent consists of 0.25g thiourea, 5.0ml o-toluidine, and5.0g glycollic acid dissolved in10.0ml distilled water and70.0ml propylene glycol.
In this determination, 0.02ml of serum to be tested and3.0ml of the reagent are placed in a test tube, mixed well, and heated in a boiling water bath for10minutes. The test tube is cooled in running tap water; the solution is transferred to a photometer cuvette, and absorbance is read at 640nm. A good agreement was observed between the results obtained by this method and by the ultraviolet method using hexokinase-glucose-6-phosphate dehydrogenase.