Water-soluble organic matter with various polarities in PM_(2.5) over Xi'an,China:Abundance,functional groups,and light absorption  

作　　者：Xueting Yang Shasha Huang Dan Li Hongmei Xu Yaling Zeng Liu Yang Diwei Wang Ningning Zhang Junji Cao Zhenxing Shen 

机构地区：[1]Department of Environmental Science and Engineering,Xi'an Jiaotong University,Xi'an,710049,China [2]School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China [3]State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an,710049,China

出　　处：《Particuology》2024年第1期281-289,共9页颗粒学报（英文版）

基　　金：supported by the Key R&D project of Shaanxi Province(grant No.2022zDLSF06-07);Chinese Academy of Sciences(CAS)“Light of West China”Program(grant No.XAB2021YN06);the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAs(grant No.SKLLQG2103,SKLLQG2110)was also thanked.

摘　　要：Humic-like substances(HULIS)are a major component of brown carbon and consequently play a major role in climate change.In this study,70 PM_(2.5) samples were collected from Xi'an in winter 2019 and summer 2020.Neutral HULIS(HULIS-n),acidic HULIS(HULIS-a),and high-polarity water-soluble organic compounds(HP-WSOC)were analyzed to determine their carbon concentrations and measure their ultraviolet-visible absorption and infrared spectra.Of the three components,HULIS-n had the highest carbon content in both winter(3.29±1.45μg m^(-3))and in summer(1.38±1.10μg m^(-3)).The semi-quantitative results for the functional groups revealed that HP-WSOC was rich in carboxylic acids and had high aromaticity in winter,whereas HULIS-n was rich in carboxylic acids in summer.Moreover,HULJS-a was richer in nitrate esters and saturated aliphatic hydrocarbons in summer than in winter.The results for specific ultraviolet absorbance(SUVA)and E_(250)/E_(365) revealed that HULIS had higher molecular weight and aromaticity in winter than in summer.HULIS-n dominated in the total light absorption of HULIS+HP-WSOC in both winter(73.08%)and summer(48.57%).Overall,the results on the carbon content,optical properties,and functional groups of WSOCs with differing polarity can improve un-derstanding of environmental and climatic effects.

关 键 词：Humic-like substances(HULIS) AROMATICITY Fourier-transform infrared(FTIR) spectroscopy Light absorbance 

分 类 号：TQ127.1[化学工程—无机化工]