| 南京北郊大气细粒子硝基苯酚类化合物污染特征与来源 |
| 摘要点击 3651 全文点击 1116 投稿时间：2021-08-11 修订日期：2021-09-22 |
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| 中文关键词 硝基苯酚 超高效液相色谱质谱联用仪(UHPLC-MS) PM2.5 正交矩阵因子分解模型(PMF) 污染来源 |
| 英文关键词 nitrophenols ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) PM2.5 positive matrix factorization(PMF) pollution sources |
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| 中文摘要 |
| 硝基苯酚类化合物是大气中普遍存在的一类含氮有机物，也是大气吸光性有机物（即棕色碳）的重要组成部分，对气候变化、空气质量和人体健康都具有重要影响.自2019年3月至2020年1月于南京北郊地区采集了共265个大气细粒子（PM2.5）日样品，并利用超高效液相色谱质谱联用仪（UHPLC-MS）定量分析样品中的8种硝基苯酚类化合物.结果表明，南京北郊大气细粒子中年均ρ（硝基苯酚）为18.77 ng·m-3，春夏秋冬四季平均值分别为16.82、8.59、17.28和44.79 ng·m-3；其浓度水平显著高于国外测量结果，但与国内部分城市如济南等较为接近.4-硝基苯酚是对总硝基苯酚类化合物贡献最大的物质，其次是4-硝基儿茶酚和2-甲氧基-5-硝基苯酚.相关性分析表明3-硝基水杨酸来源与其他7种物质显著不同.进一步正交矩阵因子分解模型对硝基苯酚的来源进行了定量解析，结果发现，该地区硝基苯酚的主要来源是交通源、燃煤生物质混合源和工业排放源，年均占比分别为32%、44%和24%；其中燃煤生物质混合源在秋冬季占据主导（占比>50%），是硝基苯酚的主要排放源；工业排放源中3-硝基水杨酸占比高于90%，与相关性分析一致.总体而言，对认识环境大气细粒子中硝基苯酚的浓度水平、组成特征及其具体来源有较重要价值. |
| 英文摘要 |
| Nitrated phenols are a group of nitrogen-containing organics ubiquitously present in ambient air, which are also important components of atmospheric light-absorbing organic matter (brown carbon) that have significant impacts on climate change, air quality, and human health. In this study, we collected a total of 265 daily filter samples of fine particles (PM2.5) in northern suburban Nanjing from March 2019 to January 2020. We used ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) to detect and quantify eight nitrated phenolic species. The results showed that the average annual concentration of total nitrated phenols in the sampling site was 18.77 ng·m-3, and the average concentrations in spring, summer, autumn, and winter were 16.82, 8.59, 17.28, and 44.79 ng·m-3, respectively. Such concentrations were obviously higher than those determined in other countries but were similar to those in domestic cities, such as Jinan. 4-Nitrophenol was the most abundant nitrated phenol, followed by 4-nitrocatechol and 2-methoxy-5-nitrophenol. Correlation analysis showed that 3-nitrosalicylic acid was from a specific source different from that of other species. Finally, we used a positive matrix factorization model to quantify the source contributions of nitrated phenols. The major sources were vehicle emissions (32%), mixed coal and biomass burning emissions (44%), and industrial emissions (24%). The mixed coal and biomass burning emissions were dominant in autumn and winter. The mass fraction of 3-nitrosalicylic acid in the factor of industrial emissions was>90%, consistent with the results of the correlation analysis. Overall, this study provides valuable insights into the understanding of concentrations, characteristics, and sources of atmospheric nitrated phenols in ambient air. |
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