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Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene

The organic component is the most abundant fraction of atmospheric submicron particles, while the formation mechanisms of secondary organic aerosol (SOA) are not fully understood. The effects of sulfate seed aerosols on SOA formation were investigated with a series of experiments carried out using a...

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Autores principales: Chu, Biwu, Liggio, John, Liu, Yongchun, He, Hong, Takekawa, Hideto, Li, Shao-Meng, Hao, Jiming
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5216392/
https://www.ncbi.nlm.nih.gov/pubmed/28059151
http://dx.doi.org/10.1038/srep40311
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author Chu, Biwu
Liggio, John
Liu, Yongchun
He, Hong
Takekawa, Hideto
Li, Shao-Meng
Hao, Jiming
author_facet Chu, Biwu
Liggio, John
Liu, Yongchun
He, Hong
Takekawa, Hideto
Li, Shao-Meng
Hao, Jiming
author_sort Chu, Biwu
collection PubMed
description The organic component is the most abundant fraction of atmospheric submicron particles, while the formation mechanisms of secondary organic aerosol (SOA) are not fully understood. The effects of sulfate seed aerosols on SOA formation were investigated with a series of experiments carried out using a 9 m(3) smog chamber. The presence of FeSO(4) or Fe(2)(SO(4))(3) seed aerosols decreased SOA yields and increased oxidation levels in both ozonolysis and OH-oxidation of α-pinene compared to that in the presence of ZnSO(4) or (NH(4))(2)SO(4). These findings were explained by metal-mediated aerosol-phase oxidation of organics: reactive radicals were generated on FeSO(4) or Fe(2)(SO(4))(3) seed aerosols and reacted further with the organic mass. This effect would help to explain the high O/C ratios of organics in ambient particles that thus far cannot be reproduced in laboratory and model studies. In addition, the gap in the SOA yields between experiments with different seed aerosols was more significant in OH-oxidation experiments compared to ozonolysis experiments, while the gap in estimated O/C ratios was less obvious. This may have resulted from the different chemical compositions and oxidation levels of the SOA generated in the two systems, which affect the branching ratio of functionalization and fragmentation during aerosol oxidation.
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spelling pubmed-52163922017-01-10 Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene Chu, Biwu Liggio, John Liu, Yongchun He, Hong Takekawa, Hideto Li, Shao-Meng Hao, Jiming Sci Rep Article The organic component is the most abundant fraction of atmospheric submicron particles, while the formation mechanisms of secondary organic aerosol (SOA) are not fully understood. The effects of sulfate seed aerosols on SOA formation were investigated with a series of experiments carried out using a 9 m(3) smog chamber. The presence of FeSO(4) or Fe(2)(SO(4))(3) seed aerosols decreased SOA yields and increased oxidation levels in both ozonolysis and OH-oxidation of α-pinene compared to that in the presence of ZnSO(4) or (NH(4))(2)SO(4). These findings were explained by metal-mediated aerosol-phase oxidation of organics: reactive radicals were generated on FeSO(4) or Fe(2)(SO(4))(3) seed aerosols and reacted further with the organic mass. This effect would help to explain the high O/C ratios of organics in ambient particles that thus far cannot be reproduced in laboratory and model studies. In addition, the gap in the SOA yields between experiments with different seed aerosols was more significant in OH-oxidation experiments compared to ozonolysis experiments, while the gap in estimated O/C ratios was less obvious. This may have resulted from the different chemical compositions and oxidation levels of the SOA generated in the two systems, which affect the branching ratio of functionalization and fragmentation during aerosol oxidation. Nature Publishing Group 2017-01-06 /pmc/articles/PMC5216392/ /pubmed/28059151 http://dx.doi.org/10.1038/srep40311 Text en Copyright © 2017, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Chu, Biwu
Liggio, John
Liu, Yongchun
He, Hong
Takekawa, Hideto
Li, Shao-Meng
Hao, Jiming
Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title_full Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title_fullStr Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title_full_unstemmed Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title_short Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene
title_sort influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and oh-oxidation of α-pinene
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5216392/
https://www.ncbi.nlm.nih.gov/pubmed/28059151
http://dx.doi.org/10.1038/srep40311
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