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DOI	10.5194/acp-21-4915-2021
	On the importance of atmospheric loss of organic nitrates by aqueous-phase ·OH oxidation
	Miguel González-Sánchez J.; Brun N.; Wu J.; Morin J.; Temime-Roussel B.; Ravier S.; Mouchel-Vallon C.; Clément J.-L.; Monod A.
发表日期	2021
ISSN	1680-7316
起始页码	4915
结束页码	4937
卷号	21 期号:6
英文摘要	Organic nitrates are secondary species in the atmosphere. Their fate is related to the chemical transport of pollutants from polluted areas to more distant zones. While their gas-phase chemistry has been studied, their reactivity in condensed phases is far from being understood. However, these compounds represent an important fraction of organic matter in condensed phases. In particular, their partition to the aqueous phase may be especially important for oxidized organic nitrates for which water solubility increases with functionalization. This work has studied for the first time the aqueous-phase •OH-oxidation kinetics of four alkyl nitrates (isopropyl nitrate, isobutyl nitrate, 1-pentyl nitrate, and isopentyl nitrate) and three functionalized organic nitrates (α-nitrooxyacetone, 1-nitrooxy-2-propanol, and isosorbide 5-mononitrate) by developing a novel and accurate competition kinetic method. Low reactivity was observed, with kOH ranging from 8×107 to 3.1×109 L mol-1 s-1 at 296±2 K. Using these results, a previously developed aqueous-phase structure-activity relationship (SAR) was extended, and the resulting parameters confirmed the extreme deactivating effect of the nitrate group, up to two adjacent carbon atoms. The achieved extended SAR was then used to determine the •OH-oxidation rate constants of 49 organic nitrates, including hydroxy nitrates, ketonitrates, aldehyde nitrates, nitrooxy carboxylic acids, and more functionalized organic nitrates such as isoprene and terpene nitrates. Their multiphase atmospheric lifetimes towards •OH oxidation were calculated using these rate constants, and they were compared to their gas-phase lifetimes. Large differences were observed, especially for polyfunctional organic nitrates: for 50% of the proposed organic nitrates for which the •OH reaction occurs mainly in the aqueous phase (more than 50% of the overall removal), their •OH-oxidation lifetimes increased by 20% to 155% under cloud/fog conditions (liquid water content LWC=0.35 gm-3). In particular, for 83% of the proposed terpene nitrates, the reactivity towards •OH occurred mostly (> 98 %) in the aqueous phase, while for 60% of these terpene nitrates, their lifetimes increased by 25% to 140% compared to their gas-phase reactivity. We demonstrate that these effects are of importance under cloud/fog conditions but also under wet aerosol conditions, especially for the terpene nitrates. These results suggest that considering aqueous-phase •OH-oxidation reactivity of biogenic nitrates is necessary to improve the predictions of their atmospheric fate. © 2021 Author(s).
语种	英语
scopus关键词	aerosol; aqueous solution; atmospheric chemistry; hydroxyl radical; kinetics; organic nitrogen; oxidation
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/247011
作者单位	Aix Marseille Univ, CNRS, LCE, Marseille, France; Aix Marseille Univ, CNRS, ICR, Marseille, France; Laboratoire d'Aérologie, Université de Toulouse, CNRS, UPS, Toulouse, France
推荐引用方式 GB/T 7714	Miguel González-Sánchez J.,Brun N.,Wu J.,et al. On the importance of atmospheric loss of organic nitrates by aqueous-phase ·OH oxidation[J],2021,21(6).
APA	Miguel González-Sánchez J..,Brun N..,Wu J..,Morin J..,Temime-Roussel B..,...&Monod A..(2021).On the importance of atmospheric loss of organic nitrates by aqueous-phase ·OH oxidation.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(6).
MLA	Miguel González-Sánchez J.,et al."On the importance of atmospheric loss of organic nitrates by aqueous-phase ·OH oxidation".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.6(2021).