10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Characterization of Heterogeneous Oxidation Products of Polycyclic Aromatic Hydrocarbons Using Online Mass Spectrometry
JAMES ROWE, Christopher Lim, Jesse Kroll, MIT
Abstract Number: 1255 Working Group: Health Related Aerosols
Abstract Polycyclic aromatic hydrocarbons (PAHs) are abundant environmental pollutants that can be toxic, mutagenic, and/or carcinogenic. These compounds are susceptible to oxidation in the atmosphere; this can affect their impact on human health, since oxidation processes will degrade the parent PAH molecule, but can also form secondary functionalized products that are potentially more toxic than the parent. Since most PAHs spend a large fraction of their atmospheric lifetimes in the particle phase, the identification of heterogeneous oxidation products is imperative for the understanding how atmospheric exposure might affect the health risk of PAHs. In this study, we simulated the heterogeneous reaction of PAH particles in the laboratory by exposing PAH-containing particles to gas-phase hydroxyl radicals (OH) within a flow tube reactor. PAH compounds were condensed onto ammonium sulfate seed particles and passed through the flow tube under conditions equivalent to ~1 week of atmospheric exposure to OH. The effluent was then analyzed using a suite of aerosol instruments, including an Aerosol Mass Spectrometer (AMS) and a Scanning Mobility Particle Sizer (SMPS). Together these measurements enable the characterization of product compounds, providing insight into potential reaction mechanisms and offering targets for future studies of the chemistry and health impacts of atmospheric PAHs.