Molecular characterization of dissolved organic matters in winter atmospheric fine particulate matters (PM2.5) from a coastal city of northeast China
Molecular characterization of dissolved organic matters in winter atmospheric fine particulate matters (PM2.5) from a coastal city of northeast China
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东北沿海城市冬季大气细颗粒物（PM2.5）溶解有机物的分子特征
DOI：
10.1016/j.scitotenv.2019.06.418
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发表时间：
2019-11-01
影响因子：
9.8
通讯作者：
Chen, Jiping
中科院分区：
文献类型：
--
作者：
Ning, Cuiping;Gao, Yuan;Chen, Jiping
细颗粒物（PM2.5）中的溶解性有机物（DOM 5）在全球气候变化和碳循环中起着至关重要的作用。然而，由于其超复杂性，DOMs的化学成分知之甚少。采用高分辨傅里叶变换离子回旋共振质谱仪对大连市采暖期大气PM2. 5中的DOM 5进行了分析，并对其分子组成进行了表征。DOM 5具有多种单同位素分子式，可分为CHO、CHNO、CHOS和CHNOS亚类。在雾霾天采集的DOM 5中共鉴定出014228个分子式，而在正常天气采集的DOM 5中仅鉴定出2313个分子式。CHO组在正常天气中占主导地位，而CHNO组在雾霾天的贡献率显著较高。含硫组（CHOS和CHNOS）在正常和雾霾天的相对百分比最高。此外，根据化学成分分析，讨论了潜在的排放源。货车Kreve lent图表明，DOM中类木质素和蛋白质氨基糖是最丰富的亚类;在雾霾天和正常天气，大连市PM2. 5中DOM的生物来源分别占78%和94%。雾霾天中更多的化合物来源于人为排放。(C)2019 Elsevier B. V.版权所有。
Dissolved organic matters (DOM5) in fine particulate matters (PM2.5) play a crucial role in global climate change and carbon cycle. However, the chemical components of DOMs are poorly understood due to its ultra-complexity. In this study, DOM5 in atmospheric PM2.5 collected during the heating period in coastal city Dalian were analyzed with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometer, and the molecular composition was characterized. A large number of monoisotopic molecular formulas were assigned to DOM5, which could be classified into CHO, CHNO, CHOS, and CHNOS subgroups. A total 014228 molecular formulas were identified in DOM5 collected in hazy days, while only 2313 components were found in DOM5 collected in normal days. CHO group was the dominated components in normal days, whereas CHNO group gave significantly higher contributions in hazy days. The S-containing (CHOS and CHNOS) groups posed the highest relative percentages in both normal and hazy days. In addition, potential emission sources were discussed according to the chemical component analysis. The van Kreve lent diagram illustrated that lignin-like and protein amino sugar family species were the most abundant subclasses in DOMs; and 78% and 94% of DOMs in atmospheric PM2.5 collected from Dalian could come from biogenic origins in hazy and normal days, respectively. More compounds in hazy days were derived from anthropogenic emissions. (C) 2019 Elsevier B.V. All rights reserved.