Volatile degradation products of l-dehydroascorbic acid.

Volatile degradation products were isolated from a solution of L-dehydroascorbic acid in phosphate buffer solution of pH 2,4,6 and 8 heated under reflux for 3 h or left at 25 degrees C for 200 h. The products were identified by comparison of their gas chromatographic retention data, infra-red and mass spectra with those of authentic compounds. Fifteen products were identified, among which 12 had not yet been reported as degradation products of L-dehydroascorbic acid. Concentrations of 5 main degradation products, i.e. 3-hydroxy-2-pyrone, 2-furancarboxylic acid, 2-furaldehyde, acetic acid and 2-acetylfuran depended on the pH values and temperature; the presence of oxygen had no pronounced effect.