An immobilized-enzyme flow-enthalpimetric analyzer: application to glucose determination by direct phosphorylation catalyzed by hexokinase.
A novel flow-enthalpimetric analyzer is described and its use demonstrated by an analysis in which glucose is determined by its hexokinase-catalyzed phosphorylation reaction. The method depends on measurement of the temperature differential across a column packed with glass-supported immoblized enzyme. Sample volumes of 120 mul can be used to obtain a calibration curve that is linear up to 25 mmol of glucose per liter. A precision (within-day) of 5% is generally observed in the optimum concentration range where glucose is quantitatively phosphorylated. Results by the technique correlate reasonably with those by the o-toluidine and the hexokinase/glucose-6-phosphate dehydrogenase methods: Other sugars--including fructose, glucosamine, and mannose--will interfere; galactose does not. The technique is amenable to both routine and emergency analyses.
D001786:Blood Glucose / Q000032:analysis*; D002151:Calorimetry; D005069:Evaluation Studies as Topic; D006593:Hexokinase; D006801:Humans; D008722:Methods; D009005:Monosaccharides; D010084:Oxidation-Reduction; D013816:Thermodynamics
D001786:Blood Glucose; D009005:Monosaccharides; D006593:Hexokinase