DOI: 10.1016/j.atmosenv.2020.117289
论文题名: Light absorption properties of brown carbon (BrC) in autumn and winter in Beijing: Composition, formation and contribution of nitrated aromatic compounds
作者: Li X. ; Yang Y. ; Liu S. ; Zhao Q. ; Wang G. ; Wang Y.
刊名: Atmospheric Environment
ISSN: 1352-2310
出版年: 2020
卷: 223 语种: 英语
英文关键词: Absorption spectroscopy
; Aromatization
; Chromophores
; Extraction
; High performance liquid chromatography
; Light
; Light absorption
; Mass spectrometry
; Methanol
; Nitration
; Nitrogen oxides
; Organic carbon
; Salicylic acid
; Sulfur compounds
; Water absorption
; Average concentration
; Brown carbons
; Formation pathways
; High resolution mass spectrometry
; Near-ultraviolet regions
; Nitro aromatic compounds
; Secondary transformation
; Ultra-high performance liquid chromatographies
; Bromine compounds
; 2,4 dinitrophenol
; 4 nitrocatechol
; 4 nitrophenol
; aromatic compound
; brown carbon
; carbon
; catechol derivative
; methanol
; nitrate
; organic carbon
; salicylic acid
; salicylic acid derivative
; sulfate
; sulfuric acid
; unclassified drug
; absorption
; aromatic hydrocarbon
; brown carbon
; chemical composition
; concentration (composition)
; extraction method
; formation mechanism
; nitric acid
; organic carbon
; salicylic acid
; sulfuric acid
; transformation
; Article
; autumn
; biomass
; chemical composition
; China
; concentration (parameter)
; light absorption
; mass spectrometry
; meteorology
; nitration
; particulate matter
; priority journal
; reaction analysis
; seasonal variation
; solar radiation
; ultra performance liquid chromatography
; ultraviolet visible spectrophotometry
; winter
; Beijing [China]
; China
学科: Brown carbon
; Formation pathway
; Light absorption
; Nitro-aromatic compounds
中文摘要: Nitro-aromatic compounds (NACs) are an important part of brown carbon because of their strong light absorbing properties in the visible and near ultraviolet regions. In this study, the concentration and formation mechanism of eight NACs, as well as their relative contribution to the light absorption of methanol-extracted BrC, were determined from fine particle samples collected in Beijing using ultra-high performance liquid chromatography coupled with high resolution mass spectrometry and ultraviolet–visible light spectrophotometry. The average concentrations of the eight NACs were 20.27 ± 12.40 ng m−3 and 74.17 ± 50.66 ng m−3 in autumn and winter, respectively. Among the detected NACs, 4-nitrophenol (4NP) and 4-nitrocatechol (4NC) were the most abundant compounds. The correlation analysis showed that the NACs other than 2,4-dinitrophenol (2,4-DNP) are strongly intercorrelated. Significant correlations among nitro catechols (NCs), nitro salicylic acids (NSAs) and NO2 support their proposed origin from secondary formation in the presence of •OH + NO2 (daytime process) or •NO3+NO2 (nighttime process). Significant correlations among nitrate, sulfate and NSAs were also found, indicating that the nitration of salicylic acid by nitric acid and sulfuric acid was another possible mechanism formation of NSAs. The methanol-extracts in winter had much higher light absorption than those in autumn, which is in agreement with the trend of NACs but contrary to the trends of PM2.5, water soluble ions, organic carbon and elemental carbon. The average absorption Ångström exponents (AAEs) during autumn and winter were 4.62 and 5.55, respectively, suggesting that secondary transformation were the main sources of BrC. The light absorption of NACs accounted for 1.17% and 3.18% of the total methanol-soluble BrC light absorption at λ = 365 nm in autumn and winter, respectively, while their masses only accounted for 0.16% and 0.44% of the OC, respectively, demonstrating that although NACs are not the major contributor to BrC, but they are strong BrC chromophores, and their influence on solar radiation should be included in future modeling work. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160969
Appears in Collections: 气候变化与战略
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作者单位: Department of Chemistry, Analytical and Testing Center, Capital Normal University, Beijing, 100048, China; Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 200241, China; College of Resource Environment and Tourism, Capital Normal University, Beijing, 100048, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
Recommended Citation:
Li X.,Yang Y.,Liu S.,et al. Light absorption properties of brown carbon (BrC) in autumn and winter in Beijing: Composition, formation and contribution of nitrated aromatic compounds[J]. Atmospheric Environment,2020-01-01,223