Laboratory Studies of Specific α-Pinene Nitrate Isomers and Their Contribution to Aerosols

The oxidation pathways of biogenic volatile organic compounds (BVOCs) and their respective products are still highly uncertain. One pathway of significance is the formation of organic nitrates, which can lead to secondary organic aerosol (SOA) formation and serve as a reservoir for NOx. However, connection of specific trace gases with the aerosol phase has remained elusive. Through laboratory-based α-pinene oxidation experiments in a photochemical chamber and the use of synthesized standards, the contributions of four multi-functional α-pinene nitrates to both the gas and particle phase were determined. Additionally, the fates of secondary and tertiary organic nitrates as a function of relative humidity was investigated and compared to aqueous phase hydrolysis rates. This information will further our understanding of BVOC oxidation pathways and the influence of particle phase chemistry on the production of low vapor pressure products.