| Title: | Ozonolysis of alpha-Pinene and Delta(3)-Carene Mixtures: Formation of Dimers with Two Precursors |
| Author(s): | Thomsen D; Thomsen LD; Iversen EM; Bjorgvinsdottir TN; Vinther SF; Skonager JT; Hoffmann T; Elm J; Bilde M; Glasius M; |
| Address: | "Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark. Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "The formation of secondary organic aerosol (SOA) from the structurally similar monoterpenes, alpha-pinene and Delta(3)-carene, differs substantially. The aerosol phase is already complex for a single precursor, and when mixtures are oxidized, products, e.g., dimers, may form between different volatile organic compounds (VOCs). This work investigates whether differences in SOA formation and properties from the oxidation of individual monoterpenes persist when a mixture of the monoterpenes is oxidized. Ozonolysis of alpha-pinene, Delta(3)-carene, and a 1:1 mixture of them was performed in the Aarhus University Research on Aerosol (AURA) atmospheric simulation chamber. Here, approximately 100 ppb of monoterpene was oxidized by 200 ppb O(3) under dark conditions at 20 degrees C. The particle number concentration and particle mass concentration for ozonolysis of alpha-pinene exceed those from ozonolysis of Delta(3)-carene alone, while their mixture results in concentrations similar to alpha-pinene ozonolysis. Detailed offline analysis reveals evidence of VOC-cross-product dimers in SOA from ozonolysis of the monoterpene mixture: a VOC-cross-product dimer likely composed of the monomeric units cis-caric acid and 10-hydroxy-pinonic acid and a VOC-cross-product dimer ester likely from the monomeric units caronaldehyde and terpenylic acid were tentatively identified by liquid chromatography-mass spectrometry. To improve the understanding of chemical mechanisms determining SOA, it is relevant to identify VOC-cross-products" |
| Keywords: | Humans *Volatile Organic Compounds/chemistry *Air Pollutants/chemistry Aerosols/chemistry Monoterpenes/chemistry *Ozone/chemistry aerosol formation monoterpene oxidation secondary organic aerosol sequential spot sampler; |
| Notes: | "MedlineThomsen, Ditte Thomsen, Lotte Dyrholm Iversen, Emil Mark Bjorgvinsdottir, Thuridur Nott Vinther, Sofie Falk Skonager, Jane Tygesen Hoffmann, Thorsten Elm, Jonas Bilde, Merete Glasius, Marianne eng 2022/11/11 Environ Sci Technol. 2022 Dec 6; 56(23):16643-16651. doi: 10.1021/acs.est.2c04786. Epub 2022 Nov 10" |
