Synergistic O₃ + OH oxidation pathway to extremely low-volatility dimers revealed in β-pinene secondary organic aerosol.

ABSTRACT: Dimeric compounds contribute significantly to the formation and growth of atmospheric secondary organic aerosol (SOA) derived from monoterpene oxidation. However, the mechanisms of dimer production, in particular the relevance of gas- vs. particle-phase chemistry, remain unclear. Here, through a combination of mass spectrometric, chromatographic, and synthetic techniques, we identify a suite of dimeric compounds (C_15-19H_24-32O_5-11) formed from concerted O₃ and OH oxidation of β-pinene (i.e., accretion of O₃- and OH-derived products/intermediates). These dimers account for an appreciable fraction (5.9-25.4%) of the β-pinene SOA mass and are designated as extremely low-volatility organic compounds. Certain dimers, characterized as covale

SUBMITTER: Kenseth CM 

PROVIDER: S-EPMC6099901 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature