The photo-oxidation of certain organic substances in the presence of fluorescent dyes

Abstract

O consumption due to photo-oxidation of organic compounds was determined in a Barcroft apparatus. All aliphatic compounds tested were inactive. In the aromatic series, a hydroxyl group, and an amino group on a side chain such as in tyrosine or phenyl hydrazine, the presence of a double bond, and the purine group derivatives all undergo photo-oxidation. The curve obtained by plotting the logarithm of the O consumption and the time indicates that the photo-oxidation of tyrosine is a monomolecular reaction following the law of mass action. The photo-catalyst is gradually destroyed during the reaction. KCN, glass powder, and ionized Fe salts have no accelerating action. H2O2 is not formed during the reaction. Methylene blue is capable of acting both as a H acceptor and as a photo-catalyst, and is decolorized when exposed to visible light in the presence of tyrosine.