AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Julia Montoya-Aguilera, PhD Graduate Student, Government - Formation and Properties of Nitrogen-Containing Organic Compounds in Secondary Organic Aerosol (SOA)
JULIA MONTOYA-AGUILERA, University of California, Irvine
Abstract Number: 217 Working Group: Meet the Job Seekers
Abstract Inorganic nitrogen contribution to particulate matter (PM) is well represented in air quality models. Missing from models is the contribution of nitrogen organic compounds (NOC) to PM. My PhD research explores how NOC can be produced and their effect on the amount and properties of SOA, a large component of PM. Two mechanisms for the formation of NOC in SOA were explored: (a) oxidation of a N-containing biogenic precursor (indole); (b) reactions of SOA with reduced nitrogen compounds, NH3 and dimethyl amine (DMA), in a smog chamber. I largely examined optical properties (UV-Vis) and detailed molecular composition (PTR-ToF-MS, ToF-AMS, DART-MS) of the resulting SOA. Some findings are below:
• Indole oxidation by OH, O3 or NO3 efficiently produces brown SOA; indole derivatives, such as tryptanthrin, indirubin, indigo dye, and indoxyl red contribute to the visible absorption of indole SOA. The photooxidation part of this study was published (Montoya-Aguilera et al., Atmos. Chem. Phys., 2017); the O3 and NO3 oxidation part describing our collaboration with the Dr. Yinon Rudich group is being written.
• Reactive uptake of NH3 or DMA by low-NOx SOA (toluene, cedrene, or limonene) does not change SOA particle mass but does change particle composition and color due to the formation of NOC, with uptake coefficients ranging from 10-5 to 10-3. Preliminary results were published (Montoya-Aguilera et al., ACS Symposium series, volume 1299).
• Prof. Donald Dabdub’s group simulated the effect of indole SOA (Montoya-Aguilera et al., 2017) and NH3 uptake by SOA (Horne et al., Atmos. Environ., 2018; Zhu et al., Atmos. Chem. Phys., 2018) on air-quality.
Overall, this PhD work highlights the novel chemistry and important properties of NOC in the atmospheric environment.
Job Type of Interest: government Geographical Preference: western U.S.