Determination of glucose and fructose in mixtures by a kinetic method with chemiluminescence detection

A kinetic method of analysis is described, based on oxidation by periodate for the determination of glucose and fructose in sample solutions. The method combines flow injection and chemiluminescence (CL) detection. The detection is based on the CL signal generated during oxidation of pyrogallol by periodate. The method is selective for the determination of vic-diols and polyols; the method is designed to determine hexose contents as low as 200 mu g. However, the method can be tailored for even lower amounts (10 times less). When the total hexose concentration is known, the individual fructose and glucose content can be determined from the rate constant that best-fits the kinetic data; the relative standard deviation of three independent kinetic experiments with the same ratio of concentrations was found to be within 2% and the standard error of the rate constant from the fitting treatment was found to be less than 10% in all samples of different concentration ratios between glucose and fructose. The method can be automated and controlled by computer software. Data points from two kinetic experiments with different sample quantities in the reaction mixture are required for the determination of the total hexose content and the individual fractions of glucose and fructose. (C) 1999 Elsevier Science B.V. All rights reserved.