Title: | Formation of Highly Oxidized Organic Compounds and Secondary Organic Aerosol from alpha-Thujene Ozonolysis |
Author(s): | Dam M; Thomas AE; Smith JN; |
Address: | "Department of Chemistry, University of California Irvine, 1120 Natural Sciences II, Irvine, California 92697-2025, United States" |
ISSN/ISBN: | 1520-5215 (Electronic) 1089-5639 (Linking) |
Abstract: | "We conducted laboratory chamber experiments to probe the gas- and particle-phase composition of oxidized organics and secondary organic aerosol (SOA) formed from alpha-thujene ozonolysis under different chemical regimes. The formation of low-volatility compounds was observed using chemical ionization mass spectrometry with nitrate (NO(3)(-)) and iodide (I(-)) reagent ions. The contribution of measured low-volatility compounds to particle growth was predicted using a simple condensational growth model and found to underpredict the measured growth rates in our chamber (on the order of several nm min(-1)). The yields of low-volatility compounds and SOA mass were similar to those of other monoterpene ozonolysis systems. While semivolatile compounds C(10)H(14-16)O(3-7) were measured most abundantly with I(-) reagent ion, a large fraction of products measured with NO(3)(-) were C(5-7) fragments with predicted intermediate volatility. Additionally, particle composition was measured with ultrahigh-performance liquid chromatography with high-resolution mass spectrometry and compared to particle composition from alpha-pinene ozonolysis. Structural isomers were identified from tandem mass spectrometry analysis of two abundant product ions (C(8)H(13)O(5)(-), C(19)H(27)O(7)(-)). Our results indicate that although this system efficiently generates low-volatility organics and SOA under the conditions studied, fragmentation pathways that produce more highly volatile products effectively compete with these processes" |
Notes: | "PubMed-not-MEDLINEDam, Michelia Thomas, Adam E Smith, James N eng 2023/08/15 J Phys Chem A. 2023 Aug 24; 127(33):6989-6998. doi: 10.1021/acs.jpca.3c02584. Epub 2023 Aug 15" |