Aerosol formation in the cyclohexene-ozone system

Atmospheric oxidation of certain volatile organic compounds can lead to products of sufficiently low vapor pressure that the products partition into the aerosol phase, producing what is termed secondary organic aerosol. Cyclohexene has long been known to produce aerosol upon photooxidation. In this study, we obtain molecular product information especially for those species that partition between the gas and particle phases. Compounds identified in the aerosol phase include hydroxyglutaric acid, adipic acid, and hydroxyadipic acid. In accord with previous studies, pentanal is found to be the predominant identified gasphase products, at a molar yield of 17%. Possible explanations for the presence of relatively high vapor pressure compounds in the aerosol phase are advanced.