The ozonation of benz[a]anthracene: pathway and product identification

The pathway for the ozonolysis of benz[a]anthracene (BaA) (ACS standard named), a polycyclic aromatic hydrocarbon (PAH), has been described in this paper. BaA was dissolved in a 90% acetonitrile:water (v/v) mixture to achieve an initial concentration of 1 mM. The ozonolysis of BaA was evaluated using different ozone dosages. The ozonation products were identified by gas chromatography/mass spectrometry (GC/MS). Fifteen products including eight pairs of isomers were identified. Ozone reacted with BaA simultaneously by bond and atom attack. Ozone attack on the carbon at the 7 and/or 12 position produced the quinone or hydroxyl functional groups. The bond attack type of reaction occurred at the 5,6 position and caused ring cleavage resulting in phenyl–naphthyl type products. Ozonolysis of BaA in this solvent mixture occurred preferentially by bond attack rather than by the atom attack type of reaction.