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DOI	10.1016/j.atmosenv.2020.118140
	Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols
	Loisel G.; Mekic M.; Liu S.; Song W.; Jiang B.; Wang Y.; Deng H.; Gligorovski S.
发表日期	2021
ISSN	1352-2310
卷号	246
英文摘要	The ionic strength can affect the photochemical reactions occurring in the liquid core of the aerosol deliquescent particles. Yet, the investigations related to ionic strength effect on aqueous-phase reactions are limited. Here we assess the photochemical degradation of a typical lignin-derived compound, vanillin (VL), upon addition of either sodium nitrate (NaNO3) or sodium sulfate (Na2SO4). The UV-VIS absorption spectra of VL exhibits a hyperchromic effect and a bathochromic shift of the n→π* absorption band, in going from λmax = 310 nm in the dilute aqueous phase to λmax = 346 nm at I = 0.3 M adjusted by Na2SO4. A hypsochromic shift of the n→π* absorption band of VL, in going from λmax = 310 nm in the dilute liquid water to λmax = 303 nm at Ieff = 0.124 M is observed when the ionic strength was adjusted with NaNO3. At fixed pH ≈ 4, representing both the cloud droplets and the liquid core of the aerosol particles, the pseudo-first-order rate constant, k1st (Ieff.→0) = (1.5 ± 0.2) x 10−5 s−1, in dilute aqueous solution (Ieff = 0 M, NaNO3), linearly decreases to (k1st = (3.7 ± 0.2) x 10−6 s−1), at Ieff = 0.124 M (NaNO3) with kinetic salting coefficient b = -(4.8 ± 0.2) L mol−1. The very subtle pH change of the absorption spectra of irradiated VL is observed due to the formation of carboxylic acids, hydroxylated compounds and oligomers which presence was confirmed by FT-ICR MS analysis. Most likely aliphatic like CHO compounds are formed upon photodegradation of VL in dilute aqueous phase while the condensed aromatic CHO and CHON compounds are produced in presence of nitrate ions (Ieff = 0.124 M). These results suggest that inorganic ions present in the liquid water of aerosols alters the kinetics and the product formation of photochemical degradation of organic compounds which in turn can affect the light absorption properties of aerosols. © 2020 Elsevier Ltd
关键词	Aerosol Biomass burning FT-ICR MS Ionic strength Methoxyphenols Photochemistry UV-VIS spectroscopy
语种	英语
scopus关键词	Aerosols; Aliphatic compounds; Light absorption; Liquids; Mass spectrometry; Nitrates; Photochemical reactions; Rate constants; Sodium nitrate; Sodium sulfate; Sulfur compounds; Ultraviolet spectroscopy; Water absorption; Absorption property; Aqueous phase reactions; Dilute aqueous solution; Hypsochromic shifts; Photochemical degradation; Pseudo first order rate constants; Salting coefficient; UV-VIS absorption spectra; Ionic strength; carboxylic acid; guaiacol; nitrate; oligomer; organic nitrate; sodium nitrate; sodium sulfate; vanillin; water; absorption; aerosol; aqueous solution; carboxylic acid; dilution; ionic liquid; lignin; nitrate; photochemistry; photodegradation; reaction kinetics; absorption; aerosol; aqueous solution; Article; biomass; data analysis software; fourier transform ion cyclotron resonance mass spectrometry; ionic strength; kinetic parameters; mass spectrometry; pH; photochemistry; photodegradation; priority journal; rate constant; ultraviolet visible spectroscopy; Aerosols; Aliphatic Compounds; Light Absorption; Liquids; Nitrates; Sodium Nitrate
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248649
作者单位	State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510 640, China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 10069, China
推荐引用方式 GB/T 7714	Loisel G.,Mekic M.,Liu S.,et al. Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols[J],2021,246.
APA	Loisel G..,Mekic M..,Liu S..,Song W..,Jiang B..,...&Gligorovski S..(2021).Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols.ATMOSPHERIC ENVIRONMENT,246.
MLA	Loisel G.,et al."Ionic strength effect on the formation of organonitrate compounds through photochemical degradation of vanillin in liquid water of aerosols".ATMOSPHERIC ENVIRONMENT 246(2021).