Photo-promoted Hypochlorite Oxidation of α-Amino Acids. Kinetics and Irradiation Effect for the Strecker Degradation

Article abstract of DOI:10.1246/bcsj.54.2057

Hypochlorite oxidation of simple α-amino acids (the Strecker degradation) in aqueous solutions has been studied in the dark and under UV-irradiation.UV-spectra, iodometry, and amino acid determination (2,4-dinitrofluorobenzene method) suggest that the intermediate N-chloro amino acid is formed quickly at an initial stage, then its slow oxidative decomposition takes place to give aldehyde, carbon dioxide, and ammonia.The mechanism is also supported by the fact that the oxidation follows the first-order rate expression; -d/dt = k₁.UV-irradiation was found to promote remarkably the degradation of N-chloro amino acid.When equimolar amounts of amino acid and hypochlorite were used, the products such as unreacted amino acid, ammonia, and aldehyde were analogous to those of the dark reaction.The use of a large excess of hypochlorite under irradiation enables complete oxidative degradation of amino acid to carbon dioxide, water and nitrogen.Its application to waste water treatment is discussed.