资源环境科技发展态势分析平台

This study reports the size-resolved characterization of the chromophores in atmospheric particulate matter in Linfen, a typical coal-burning city in China. The optical properties of both the water-soluble and water-insoluble chromophores in atmospheric particulates are studied using excitation-emission matrix spectroscopy and follow the parallel factor analysis of excitation-emission matrix data. The mass absorption efficiency and normalized fluorescence volume by mass concentration of the organic carbon in methanol-soluble matter in the particulate samples are stronger than that of the water-soluble matter. We found that the total absorption (Abs), fluorescence volume (FV), mass absorption efficiency, and normalized fluorescence volume of particle extracts with sizes less than 10 mu m increased with the decreasing particle size. The total concentration of the selected seven polycyclic aromatic hydrocarbons was positively correlated with the Abs(365) and FV of both the water-soluble matter and methanol-soluble matter, but the average contribution of the selected polycyclic aromatic hydrocarbons to the total Abs and FV was very small (<3%). This study is the first to report a size-resolved characterization of the chromophores in atmospheric particulate matter. Humic-like substances tend to be present in small particles, and tryptophan-like and tyrosine-like components tend to increase with increasing particle size.