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DOI	10.1016/j.atmosenv.2020.118159
	Molecular weight-dependent abundance; absorption; and fluorescence characteristics of water-soluble organic matter in atmospheric aerosols
	Fan X.; Cai F.; Xu C.; Yu X.; Wang Y.; Xiao X.; Ji W.; Cao T.; Song J.; Peng P.
发表日期	2021
ISSN	1352-2310
卷号	247
英文摘要	Water-soluble organic matter (WSOM) plays a significant role in solar radiative forcing and atmospheric chemistry. Its chemical composition and properties are highly molecular weight (MW)-dependent, but are still poorly understood. In this study, 10 PM2.5 samples were collected at a rural site in China, and the WSOM therein was fractionated into three MW fractions, >5 kDa (F1), 1–5 kDa (F2), and <1 kDa (F3), using an ultrafiltration (UF) system. The abundance, optical properties, and fluorescence properties of the three MW fractions were comprehensively determined using a total organic carbon (TOC) analyzer, ultraviolet–visible (UV–vis) spectroscopy, and excitation-emission matrix (EEM) fluorescence spectroscopy combined with parallel factor (PARAFAC) modeling. The proportional TOC and Abs365 distributions of the MW fractions were F1:F2:F3 ≈ 24:22:54 and 40:24:36, respectively. This suggested that the major OC species in bulk WSOM were partitioned into the low MW (<1 kDa) fraction, while the major light-absorbing chromophores were partitioned into the large MW (F1 + F2, >1 kDa) fraction, and were especially prevalent in the >5 kDa fraction. The optical parameters, i.e., SUVA254 and MAE365, generally increased with the apparent increase in MW, suggesting that the higher MW fractions might have a stronger aromaticity and light absorption capacity. The EEM-PARAFAC analysis identified three humic-like substances (HULIS) (C1–C3) and one protein-like (C4) substance for all MW fractions, of which the proportional distributions were observed as C1:C2:C3:C4 ≈ 20:24:41:15, 21:23:44:12, and 41:22:13:24 for F1, F2, and F3, respectively. This indicated that the >1 kDa fraction was enriched in highly-oxygenated HULIS (C3), whereas the <1 kDa fraction had more less-oxygenated HULIS (C1) and protein-like (C4) substances than the >1 kDa fraction. The study provided a detailed insight of the MW-dependent characteristics of WSOM by reducing their heterogeneity and complexity, which is of great significance for further understanding the chemical properties and structures of WSOM. © 2020 Elsevier Ltd
英文关键词	Atmospheric aerosols; Atmospheric radiation; Biogeochemistry; Chromophores; Fluorescence; Fluorescence spectroscopy; Light absorption; Molecular weight; Optical emission spectroscopy; Optical properties; Organic carbon; Proteins; Water absorption; Chemical compositions; Dependent characteristics; Excitation-emission matrix fluorescences; Fluorescence characteristics; Fluorescence properties; Humic-like substances; Molecular weight dependent; Water-soluble organic matter; Atmospheric chemistry
语种	英语
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/169027
作者单位	College of Resource and Environment, Anhui Science and Technology University, Fengyang, 233100, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Longpan Road 159, Nanjing, Jiangsu 210037, China
推荐引用方式 GB/T 7714	Fan X.,Cai F.,Xu C.,et al. Molecular weight-dependent abundance; absorption; and fluorescence characteristics of water-soluble organic matter in atmospheric aerosols[J],2021,247.
APA	Fan X..,Cai F..,Xu C..,Yu X..,Wang Y..,...&Peng P..(2021).Molecular weight-dependent abundance; absorption; and fluorescence characteristics of water-soluble organic matter in atmospheric aerosols.Atmospheric Environment,247.
MLA	Fan X.,et al."Molecular weight-dependent abundance; absorption; and fluorescence characteristics of water-soluble organic matter in atmospheric aerosols".Atmospheric Environment 247(2021).