State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Department of Global Health, School of Public Health, Peking University, Beijing 100191, China.
Sci Total Environ. 2022 Aug 1;832:155081. doi: 10.1016/j.scitotenv.2022.155081. Epub 2022 Apr 8.
High-performance liquid chromatography-size exclusion chromatography and excitation-emission matrix (EEM) fluorescence spectroscopy were used to analyze the seasonal variations and potential sources of molecular weight (MW) separated light-absorbing chromophores and fluorophores of water-soluble organic compounds (WSOC) and methanol-soluble organic compounds (MSOC) in PM in cold areas of northern China. The results showed that the light-absorbing organics in MSOC had larger weight-average MW (M) (3.19 kDa) and number-average MW (M) (1.13 kDa) compared with WSOC (M: 1.41 kDa, M: 0.692 kDa). The light-absorption of organics showed a trend of winter>spring>autumn>summer and increased on air pollution days. Three fluorescent components including humic-like, protein-like, and terrestrial humic-like components in WSOC were extracted by parallel factor analysis (PARAFAC). Fluorophores in WSOC were dominated by humic-like and terrestrial humic-like components (67.7%). Three fluorescent components extracted from MSOC were low oxidation humic-like, polycyclic aromatic hydrocarbon (PAH)-like, and protein-like components respectively. It is worth noting that compared with WSOC, MSOC may have a higher human health risk due to the presence of PAH-like components. The combination of PARAFAC and self-organizing map had the potential to identify potential sources of fluorophores. It provided a new perspective for comprehensively exploring the characteristics of fluorophores in aerosols. This study provided a reference for further understanding the chemical composition and optical properties of organic aerosols in the cold regions of northern China.
高效液相色谱-体积排阻色谱和激发-发射矩阵（EEM）荧光光谱法被用于分析中国北方寒冷地区大气颗粒物中 PM 中水溶性有机化合物（WSOC）和甲醇溶性有机化合物（MSOC）中分子量（MW）分离的光吸收发色团和荧光团的季节性变化及其潜在来源。结果表明，与 WSOC 相比，MSOC 中的吸光有机物具有更大的重均分子量（M）（3.19 kDa）和数均分子量（M）（1.13 kDa）。有机物的吸光度呈现冬季>春季>秋季>夏季的趋势，并在空气污染日增加。通过平行因子分析（PARAFAC）从 WSOC 中提取了三种荧光成分，包括类腐殖质、类蛋白和陆源类腐殖质成分。WSOC 中的荧光团主要由类腐殖质和陆源类腐殖质成分组成（67.7%）。从 MSOC 中提取的三种荧光成分分别为低氧化类腐殖质、多环芳烃（PAH）类和类蛋白成分。值得注意的是，与 WSOC 相比，MSOC 中可能由于存在 PAH 类成分而具有更高的人类健康风险。PARAFAC 和自组织映射的组合具有识别荧光团潜在来源的潜力。它为全面探索气溶胶中荧光团的特性提供了新的视角。本研究为进一步了解中国北方寒冷地区有机气溶胶的化学组成和光学性质提供了参考。
