Enzymatic Blood Glucose Determination by Colorimetry of N,N-Diethylaniline-4-Aminoantipyrine

The hydrogen peroxide produced from glucose by glucose oxidase action at pH 7 is determined by the peroxidase oxidative coupling of N,N-diethylaniline with 4-amino-antipyrine. A 20-µl sample of plasma or serum is reacted at room temperature for 10 min. The sensitivity of the method is such that 60 µg of glucose (300 mg/dl) in a final volume of 5 ml gives an absorbance of 0.8 at 553 nm with a 1-cm cell. Absorbances are linearly related to glucose concentrations as high as 10.00 g/liter.