Abstract
The photochemical degradation of dibenzothiophene in aqueous solution was studied to elucidate the fate of crude oil components after an oil spill. The major reaction pathway is based on the oxidation of a benzo ring to form benzothiophene-2,3-dicarboxylic acid and ultimately, after opening of the thiophene ring, 2-sulfobenzoic acid as the stable photolysis product. Opening of both benzo rings also occurs in which case thiophenedi-, -tri- and -tetracarboxylic acids are formed. One minor reaction pathway leads to the sulfone by oxidation of the sulfur atom. The products were identified through gas chromatography-mass spectrometry and comparison with reference compounds.