Chemical reactions induced by ultrasound and γ-rays in aqueous solutions of l-ascorbic acid

The degradation of l-ascorbic acid in aqueous solutions by ultrasound and ionising radiation was more extensive in the presence than in the absence of air. The primary products were l-erythro-2,3-hexodiulosonic acid, cis- and trans-l-glycero-4-hexulos-2-enonic acid; the secondary products were 2-pentulosonic acid, 4-pentulos-2-enonic acid, tetronic acid, and glyceric acid; and the tertiary product was tetraric acid. The formation of products with less than six carbon atoms was especially effective during irradiation in the presence of air. A mechanism for the degradation of l-ascorbic acid by sonolysis and radiolysis is proposed.