Molecular composition and volatility of isoprene photochemical oxidation secondary organic aerosol under low- and high-NO<sub><i>x</i></sub> conditions
-
Published:2017-01-04
Issue:1
Volume:17
Page:159-174
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
D'Ambro Emma L.ORCID, Lee Ben H., Liu JiumengORCID, Shilling John E.ORCID, Gaston Cassandra J., Lopez-Hilfiker Felipe D., Schobesberger SiegfriedORCID, Zaveri Rahul A.ORCID, Mohr ClaudiaORCID, Lutz Anna, Zhang Zhenfa, Gold Avram, Surratt Jason D.ORCID, Rivera-Rios Jean C., Keutsch Frank N., Thornton Joel A.
Abstract
Abstract. We present measurements of secondary organic aerosol (SOA) formation from isoprene photochemical oxidation in an environmental simulation chamber at a variety of oxidant conditions and using dry neutral seed particles to suppress acid-catalyzed multiphase chemistry. A high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) utilizing iodide-adduct ionization coupled to the Filter Inlet for Gases and Aerosols (FIGAERO) allowed for simultaneous online sampling of the gas and particle composition. Under high-HO2 and low-NO conditions, highly oxygenated (O : C ≥ 1) C5 compounds were major components (∼ 50 %) of SOA. The SOA composition and effective volatility evolved both as a function of time and as a function of input NO concentrations. Organic nitrates increased in both the gas and particle phases as input NO increased, but the dominant non-nitrate particle-phase components monotonically decreased. We use comparisons of measured and predicted gas-particle partitioning of individual components to assess the validity of literature-based group-contribution methods for estimating saturation vapor concentrations. While there is evidence for equilibrium partitioning being achieved on the chamber residence timescale (5.2 h) for some individual components, significant errors in group-contribution methods are revealed. In addition, > 30 % of the SOA mass, detected as low-molecular-weight semivolatile compounds, cannot be reconciled with equilibrium partitioning. These compounds desorb from the FIGAERO at unexpectedly high temperatures given their molecular composition, which is indicative of thermal decomposition of effectively lower-volatility components such as larger molecular weight oligomers.
Funder
U.S. Department of Energy National Science Foundation
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference70 articles.
1. Baasandorj, M., Papanastasiou, D. K., Talukdar, R. K., Hasson, A. S., and Burkholder, J. B.: (CH3)(3)COOH (tert-butyl hydroperoxide): OH reaction rate coefficients between 206 and 375 K and the OH photolysis quantum yield at 248 nm, Phys. Chem. Chem. Phys., 12, 12101–12111, https://doi.org/10.1039/c0cp00463d, 2010. 2. Capouet, M. and Müller, J.-F.: A group contribution method for estimating the vapour pressures of a-pinene oxidation products, Atmos. Chem. Phys., 6, 1455–1467, https://doi.org/10.5194/acp-6-1455-2006, 2006. 3. Claeys, M., Graham, B., Vas, G., Wang, W., Vermeylen, R., Pashynska, V., Cafmeyer, J., Guyon, P., Andreae, M. O., Artaxo, P., and Maenhaut, W.: Formation of secondary organic aerosols through photooxidation of isoprene, Science, 303, 1173–1176, https://doi.org/10.1126/science.1092805, 2004. 4. Compernolle, S., Ceulemans, K., and Müller, J.-F.: EVAPORATION: a new vapour pressure estimation methodfor organic molecules including non-additivity and intramolecular interactions, Atmos. Chem. Phys., 11, 9431–9450, https://doi.org/10.5194/acp-11-9431-2011, 2011. 5. Ding, X., Zheng, M., Yu, L. P., Zhang, X. L., Weber, R. J., Yan, B., Russell, A. G., Edgerton, E. S., and Wang, X. M.: Spatial and seasonal trends in biogenic secondary organic aerosol tracers and water-soluble organic carbon in the southeastern United States, Environ. Sci. Technol., 42, 5171–5176, https://doi.org/10.1021/es7032636, 2008.
Cited by
59 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|