Effects of derivatization on solar-induced decomposition of polycyclic aromatic hydrocarbons in aqueous media.

The solar-induced decomposition of 10 polycyclic aromatic hydrocarbons (PAHs) was observed in aqueous media. All 10 PAHs observed were half-decomposed within 120 min. Among anthracene derivatives, the decomposition rates were: anthracene = 1-methylanthracene < 2-methylanthracene < 9-methylanthracene < 9,10-dimethylanthracene approximately 2-aminoanthracene. The addition of commercial humic acid had no effect on the decomposition rates of these PAHs. Deuterium water also hastened the decomposition of PAH. The products obtained by the solar radiation of PAH after extraction to DCM were mainly ketone and hydroxyl derivatives. To explain these results, reactivities and electron charges at the constituent carbon atoms in each anthracene derivative were examined by an ab initio molecular orbital calculation method.