Kinetics of aerobic oxidation of ascorbic acid.
Abstract The pH‐log rate profile of the rate of disappearance of ascorbic acid from an aqueous solution under aerobic conditions was determined at 67° in a pH range of 3.52 to 7.22, ionic strength 0.4. The profile shows a maximum near pKa 1 of ascorbic acid. The aerobic rate shows buffer catalysis in the pH range studied. Since ascorbic acid oxidation is readily catalyzed by metal ions, the oxidation was also followed in the presence of disodium ethylenediamine‐tetraacetate. The results duplicated those obtained by following the aerobic oxidations of ascorbic acid in the absence of a chelating agent. Thermodynamic parameters were calculated from the Arrhenius plots.