Oxidation of Ascorbic Acid in the Presence of Copper.

Abstract
Ascorbic acid (I) in acetate buffer causes precipitation of Cu2O (II) in the presence of Cu salt concns. of 0.001 [image] or greater. Less than 1 mole O2 was required for each mole I. At pH 5.95, I was oxidized very rapidly and much slower at pH 4.2. Precipitation of II begins above pH 4.5. Protein or amino acids form complex linkages with Cu and prevent II from precipitating, resulting in increase of O2 necessary for oxidation of I.