Molecular Composition and Volatility of Organic Aerosol in the Southeastern U.S.: Implications for IEPOX Derived SOA
| Autor: | Anna Lutz, Theran P. Riedel, Jason D. Surratt, Cassandra J. Gaston, Joel A. Thornton, Emma L. D'Ambro, Theo Kurtén, A. Gold, Zhenfa Zhang, Siddharth Iyer, Mattias Hallquist, Ben H. Lee, Weiwei Hu, Felipe D. Lopez-Hilfiker, Jose L. Jimenez, Claudia Mohr |
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| Rok vydání: | 2016 |
| Předmět: |
Molecular composition
010504 meteorology & atmospheric sciences 010501 environmental sciences Mass spectrometry 01 natural sciences Mass Spectrometry chemistry.chemical_compound Hemiterpenes Pentanes Butadienes Environmental Chemistry Isoprene 0105 earth and related environmental sciences Aerosols Chemical ionization Volatilisation Atmosphere Thermal decomposition General Chemistry Southeastern United States Aerosol chemistry 13. Climate action Environmental chemistry Gases Volatilization Volatility (chemistry) Environmental Monitoring |
| Zdroj: | Environmental Science & Technology. 50:2200-2209 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.5b04769 |
| Popis: | We present measurements as part of the Southern Oxidant and Aerosol Study (SOAS) during which atmospheric aerosol particles were comprehensively characterized. We present results utilizing a Filter Inlet for Gases and AEROsol coupled to a chemical ionization mass spectrometer (CIMS). We focus on the volatility and composition of isoprene derived organic aerosol tracers and of the bulk organic aerosol. By utilizing the online volatility and molecular composition information provided by the FIGAERO-CIMS, we show that the vast majority of commonly reported molecular tracers of isoprene epoxydiol (IEPOX) derived secondary organic aerosol (SOA) is derived from thermal decomposition of accretion products or other low volatility organics having effective saturation vapor concentrations10(-3) μg m(-3). In addition, while accounting for up to 30% of total submicrometer organic aerosol mass, the IEPOX-derived SOA has a higher volatility than the remaining bulk. That IEPOX-SOA, and more generally bulk organic aerosol in the Southeastern U.S. is comprised of effectively nonvolatile material has important implications for modeling SOA derived from isoprene, and for mechanistic interpretations of molecular tracer measurements. Our results show that partitioning theory performs well for 2-methyltetrols, once accretion product decomposition is taken into account. No significant partitioning delays due to aerosol phase or viscosity are observed, and no partitioning to particle-phase water or other unexplained mechanisms are needed to explain our results. |
| Databáze: | OpenAIRE |
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