气候变化领域集成服务门户(CCPortal): Experimental investigation into the volatilities of highly oxygenated organic molecules (HOMs)

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DOI	10.5194/acp-20-649-2020
	Experimental investigation into the volatilities of highly oxygenated organic molecules (HOMs)
	Peräkylä O.; Riva M.; Heikkinen L.; Quéléver L.; Roldin P.; Ehn M.
发表日期	2020
ISSN	1680-7316
起始页码	649
结束页码	669
卷号	20 期号:2
英文摘要	Secondary organic aerosol (SOA) forms a major part of the tropospheric submicron aerosol. Still, the exact formation mechanisms of SOA have remained elusive. Recently, a newly discovered group of oxidation products of volatile organic compounds (VOCs), highly oxygenated organic molecules (HOMs), have been proposed to be responsible for a large fraction of SOA formation. To assess the potential of HOMs to form SOA and to even take part in new particle formation, knowledge of their exact volatilities is essential. However, due to their exotic, and partially unknown, structures, estimating their volatility is challenging. In this study, we performed a set of continuous flow chamber experiments, supported by box modelling, to study the volatilities of HOMs, along with some less oxygenated compounds, formed in the ozonolysis of a-pinene, an abundant VOC emitted by boreal forests. Along with gaseous precursors, we periodically injected inorganic seed aerosol into the chamber to vary the condensation sink (CS) of low-volatility vapours. We monitored the decrease of oxidation products in the gas phase in response to increasing CS, and were able to relate the responses to the volatilities of the compounds. We found that HOM monomers are mainly of low volatility, with a small fraction being semi-volatile. HOM dimers were all at least low volatility, but probably extremely low volatility; however, our method is not directly able to distinguish between the two. We were able to model the volatility of the oxidation products in terms of their carbon, hydrogen, oxygen and nitrogen numbers. We found that increasing levels of oxygenation correspond to lower volatilities, as expected, but that the decrease is less steep than would be expected based on many existing models for volatility, such as SIMPOL. The hydrogen number of a compound also predicted its volatility, independently of the carbon number, with higher hydrogen numbers corresponding to lower volatilities. This can be explained in terms of the functional groups making up a molecule: high hydrogen numbers are associated with, e.g. hydroxy groups, which lower volatility more than, e.g. carbonyls, which are associated with a lower hydrogen number. The method presented should be applicable to systems other than a-pinene ozonolysis, and with different organic loadings, in order to study different volatility ranges. © 2020 Author(s).
语种	英语
scopus关键词	aerosol formation; atmospheric modeling; experiment; hydrogen; monoterpene; oxygenation; volatile organic compound
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248039
作者单位	Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland; Univ Lyon, Université Claude Bernard Lyon 1, CNRS, IRCELYON, Villeurbanne, 69626, France; Division of Nuclear Physics, Lund University, P.O. Box 118, Lund, 22100, Sweden
推荐引用方式 GB/T 7714	Peräkylä O.,Riva M.,Heikkinen L.,et al. Experimental investigation into the volatilities of highly oxygenated organic molecules (HOMs)[J],2020,20(2).
APA	Peräkylä O.,Riva M.,Heikkinen L.,Quéléver L.,Roldin P.,&Ehn M..(2020).Experimental investigation into the volatilities of highly oxygenated organic molecules (HOMs).ATMOSPHERIC CHEMISTRY AND PHYSICS,20(2).
MLA	Peräkylä O.,et al."Experimental investigation into the volatilities of highly oxygenated organic molecules (HOMs)".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.2(2020).