Modelling the photochemical fate of organic compounds in seawater: A study on singlet molecular oxygen-mediated reactions

A study on the salt effect of the singlet molecular oxygen-mediated photo-oxidation of organic compounds was carried out. The photo-oxidation rates under different solvent conditions (water plus NaCl 0.45 ; methanol and ethanol plus LiCl 0.45 ; seawater and distilled water) were compared. As a general trend the presence of salt reduces the velocity of photo-oxidation. Although solvent polarity certainly plays a common role in the photo-oxidation process, particular kinetic behaviours were obtained for the differing derivatives. The individual photo-oxidation mechanism for each family of compounds must be saved for a further discussion.