School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Sci Total Environ. 2020 May 20;718:137322. doi: 10.1016/j.scitotenv.2020.137322. Epub 2020 Feb 14.
It is essential to fully understand the physicochemical properties and sources of atmospheric chromophores to evaluate their impacts on environmental quality and global climate. Three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy is an important method for directly characterizing the occurrences, origins, and chemical behaviors of atmospheric chromophores. However, there is still a lack of adequate information on the sources and chemical structures of EEM-defined chromophores. This situation limits the extensive application of the EEM method in the study of atmospheric chromophores. Under these adverse conditions, this work uses the analysis of EEM data by the parallel factor (PARAFAC) analysis model and a comprehensive comparison of the types and abundances of different chromophores in different aerosol samples (combustion source samples, secondary organic aerosols, and ambient aerosols) to demonstrate that the EEM method can distinguish among different chromophore types and aerosol sources. Indeed, approximately half of all fluorescent substances can be attributed to specific chemicals and sources. These findings provide an important basis for the study of the sources and chemical processes of atmospheric chromophores by the EEM approach.
充分了解大气生色团的物理化学性质和来源对于评估其对环境质量和全球气候的影响至关重要。三维激发-发射矩阵（EEM）荧光光谱法是直接描述大气生色团的发生、起源和化学行为的重要方法。然而，对于 EEM 定义的生色团的来源和化学结构，仍然缺乏足够的信息。这种情况限制了 EEM 方法在大气生色团研究中的广泛应用。在这些不利条件下，本工作使用平行因子（PARAFAC）分析模型对 EEM 数据进行分析，并对不同气溶胶样品（燃烧源样品、二次有机气溶胶和环境气溶胶）中不同生色团的类型和丰度进行综合比较，证明 EEM 方法可以区分不同的生色团类型和气溶胶来源。实际上，大约一半的荧光物质可以归因于特定的化学物质和来源。这些发现为 EEM 方法研究大气生色团的来源和化学过程提供了重要依据。
