[Study on optical characteristics of chromophoric dissolved organic matter (CDOM) in rainwater by fluorescence excitation-emission matrix and absorbance spectroscopy].

摘要: The optical characteristics of chromophoric dissolved organic matter (CDOM) were determined in rain samples collected Xiamen Island, during a rainy season 2007, using fluorescence excitation-emission matrix spectroscopy associated with UV-Vis absorbance spectra. Results showed that the spectra CDOM decreased exponentially wavelength. coefficient at 300 nm [a(300)] ranged from 0. 27 to 3. 45 m(-1), which would be used as an index abundance, and mean value was 1. 08 m(-1). content earlier stage precipitation events higher than later events, implied anthropogenic sources or atmospheric pollution air mass types important contributors levels precipitation. EEMs 4 signals (2 humic-like peaks 2 protein-like peaks) rainwater samples, there significant positive correlations peak A C B S, showing their same some relationship two substance substance. strong a(300), suggested chromophores responsible for might fluorophores fluorescence. presence highly absorbing fluorescing is importance chemistry play previously unrecognized role wavelength dependent spectral attenuation solar radiation by waters.