Thermochemical determination of glucose in serum, plasma, and whole blood without prior deproteinization.
Glucose can be determined by phosphorylation in the presence of hexokinase (EC 2.7.1.1) by using Mg2+/(ATP)2- as the phosphorylating agent. A novel instrumental quantitation method is described, direct injection enthalpimetry, whereby the heat of the enzymatically catalyzed reaction was measured. The reaction was allowed to proceed to virtual completion (99.5+%) in an adiabatic Dewar vessel at 25.00 plus or minus 0.01 degrees C (range). Samples were sequentially injected into a reaction mixture consisting of hexokinase, ATP, Mg2+, and a tris(hydroxymethyl)aminomethane buffer (pH 8). Single analyses required less than 2 min for 0-3 g/liter samples. The linear dynamic range was 0.3-10 g/liter, with zero intercept and a precision and accuracy of 2%. Electrical calibration in situ obviated the need for chemical standards, and because protein and color do not interfere, no sample pretreatment was necessary before analysis.
D000255:Adenosine Triphosphate / Q000378:metabolism; D001151:Arsenic; D001786:Blood Glucose / Q000032:analysis*; D001798:Blood Proteins; D055598:Chemical Phenomena; D002621:Chemistry; D005069:Evaluation Studies as Topic; D005949:Glucose Oxidase; D006593:Hexokinase; D006801:Humans; D008982:Molybdenum; D010949:Plasma / Q000032:analysis; D013816:Thermodynamics; D014052:Toluidines
D001786:Blood Glucose; D001798:Blood Proteins; D014052:Toluidines; D008982:Molybdenum; D000255:Adenosine Triphosphate; D005949:Glucose Oxidase; D006593:Hexokinase; D001151:Arsenic