Molecular Characterization of Brown Carbon Chromophores in Atmospherically Relevant Samples and Their Gas‐Particle Distribution and Diurnal Variation in the Atmosphere
Molecular Characterization of Brown Carbon Chromophores in Atmospherically Relevant Samples and Their Gas‐Particle Distribution and Diurnal Variation in the Atmosphere
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DOI：
10.1029/2022jd038142
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发表时间：
2023-06
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影响因子：
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通讯作者：
Chong Xing;Yibei Wan;Qiongqiong Wang;Shaofei Kong;Xiangpeng Huang;X. Ge;M. Xie;Huan Yu
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文献类型：
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作者：
Chong Xing;Yibei Wan;Qiongqiong Wang;Shaofei Kong;Xiangpeng Huang;X. Ge;M. Xie;Huan Yu
通过开发非目标串联质谱实验工作流程，我们确定了五种类型的大气相关样品中 100 个棕碳 (BrC) 发色团的最可能的结构，包括环境气溶胶、生物质燃烧气溶胶、公路隧道气溶胶、甲苯二次有机气溶胶和雨水。这些发色团分为九组，即31种硝基酚、12种苯甲酸、11种含氧多环芳烃、10种酚、10种芳基酰胺/胺、9种苯基丙烯衍生物、9种香豆素和类黄酮、5种吡啶和3种硝基苯甲酸。其中，芳基酰胺/胺发色团主要存在于雨水中，为首次报道。所鉴定的发色团占 5 种样品中 300-400 nm 波长范围内总光吸收或总离子强度的 20.9%-83.5%。我们确定了每种样品类型中的特征发色团以及不同样品类型之间的相同发色团，特别是源样品和环境气溶胶之间的相同发色团。通过配备气体和气溶胶过滤入口的在线高分辨率化学电离质谱仪测量大气中 13 种 BrC 化合物的气体颗粒分布和日变化。研究发现，BrC 化合物的气体颗粒分布由其官能团、氧和碳原子数决定。含硝基的BrC化合物夜间浓度较高，而不含硝基的BrC化合物白天浓度较高。
By developing a nontarget tandem mass spectrometry experiment workflow, we identified the most probable structures of 100 brown carbon (BrC) chromophores in five types of atmospherically relevant samples including ambient aerosols, biomass burning aerosols, road tunnel aerosols, toluene secondary organic aerosol and rainwater. These chromophores were classified into nine groups, that is, 31 nitrophenols, 12 benzoic acids, 11 oxygenated polycyclic aromatic hydrocarbons, 10 phenols, 10 aryl amides/amines, 9 phenylpropene derivatives, 9 coumarins and flavonoids, 5 pyridines, and 3 nitrobenzoic acids. Among them, aryl amides/amine chromophores, which were mostly found in rainwater, were reported for the first time. The identified chromophores accounted for 20.9%–83.5% of total light absorption over 300–400 nm wavelength or total ion intensity in the 5 types of samples. We identified the characteristic chromophore groups in each sample type and identical chromophores among different sample types, especially between the source samples and ambient aerosols. Gas‐particle distribution and diurnal variation of 13 BrC compounds in the atmosphere were measured by an online high‐resolution chemical ionization mass spectrometer equipped with a Filter Inlet for Gases and Aerosols. It was found that gas‐particle distribution of BrC compounds was dictated by their functional group, oxygen and carbon atom numbers. The BrC compounds containing nitro‐group had higher nighttime concentrations, while those without nitro‐group had higher daytime concentrations.