Reactions of Ozone and Hydroxyl Radicals with Serine

Serine, a common aquatic amino acid, was treated with ozone and ozone decomposition products such as hydroxyl radicals. Scavengers and promoters were used to study ozone and hydroxyl radical reactions, respectively. Reactions of ozone and serine in the presence of hydroxyl radical scavengers led to the formation of carbonyl and carboxylic acid byproducts containing one or two carbon atoms, indicating the loss of a carbon from the original serine. Nitrite and nitrate were detected, with nitrate being the major end product from the oxidation of the amine nitrogen. Reaction of ozone with serine under radical- promoting conditions led to the detection of compounds with one, two, and three carbon atoms, indicating that rupture of the original carbon backbone did not always occur. The byproducts detected included hydroxyl, carbonyl, and carboxylic acid functional groups. Under these conditions, ammonia was the major end product for the amine nitrogen.