PRODUCTS OF BENZ[A]ANTHRACENE PHOTODEGRADATION IN THE PRESENCE OF KNOWN ORGANIC-CONSTITUENTS OF ATMOSPHERIC AEROSOLS

Little is known about atmospheric reaction mechanisms or products of p olycyclic aromatic hydrocarbons associated with aerosol particles. Pro ducts of benz[a]anthracene photodegradation were determined after irra diation of benz[a]anthracene in the presence of three common constitue nts of atmospheric aerosols previously found to accelerate benz[a]anth racene photodegradation; 9,10-anthraquinone, g-xanthone, and vanillin. Irradiation was carried out in toluene, benzene, and benzene-d(6), an d products were analyzed by GCMS, FTIR, and NMR. Among the major tenta tively identified products were benz[a]anthracene-7,12-dione, phthalic acid, phthalic anhydride, and 1,2-benzenedicarboxaldehyde. Evidence f or production of polycylic dicarboxylic acids and dialdehydes was also obtained. Product distribution was strongly influenced by solvent eff ects and dissolved aerosol constituents. The results suggest that prod ucts of PAH photodegradation in atmospheric aerosols are likely to be quite complex and strongly influenced by the organic composition of PA H-containing aerosol particles.