| Autor: |
Campbell SJ; Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.; Department of Environmental Sciences, University of Basel, Basel, Klingelbergstrasse 27, Basel 4056, Switzerland., Wolfer K; Department of Environmental Sciences, University of Basel, Basel, Klingelbergstrasse 27, Basel 4056, Switzerland., Gallimore PJ; Department of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PS, United Kingdom., Giorio C; Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K., Häussinger D; Department of Chemistry, University of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland., Boillat MA; Department of Chemistry, University of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland., Kalberer M; Department of Environmental Sciences, University of Basel, Basel, Klingelbergstrasse 27, Basel 4056, Switzerland. |
| Abstrakt: |
The ozonolysis of alkenes contributes substantially to the formation of secondary organic aerosol (SOA), which are important modulators of air quality and the Earth's climate. Criegee intermediates (CIs) are abundantly formed through this reaction. However, their contributions to aerosol particle chemistry remain highly uncertain. In this work, we present the first application of a novel methodology, using spin traps, which simultaneously quantifies CIs produced from the ozonolysis of volatile organic compounds in the gas and particle phases. Only the smallest CI with one carbon atom was detected in the gas phase of a β-caryophyllene ozonolysis reaction system. However, multiple particle-bound CIs were observed in β-caryophyllene SOA. The concentration of the most abundant CI isomer in the particle phase was estimated to constitute ∼0.013% of the SOA mass under atmospherically relevant conditions. We also demonstrate that the lifetime of CIs in highly viscous SOA particles is at least on the order of minutes, substantially greater than their gas-phase lifetime. The confirmation of substantial concentrations of large CIs with elongated lifetimes in SOA raises new questions regarding their influence on the chemical evolution of viscous SOA particles, where CIs may be a previously underestimated source of reactive species. |
