title: Fluorescence excitation-emission matrix spectra coupled with parallel factor and regional integration analysis to characterize organic matter humification.
abstract: The present several humification indexes cannot provide the whole fluorescence information on organic matter composition and the evaluation results from them are inconsistent sometimes. In this study, fluorescence excitation-emission matrix spectra coupled with parallel factor analysis and fluorescence regional integration analysis were utilized to investigate organic matter humification, and the projection pursuit cluster (PPC) model was applied to form a suitable index for overcoming the difficulties in multi-index evaluation. The result showed that the ratio between the volume of humic- and fulvic-like fluorescence region and the volume of protein-like fluorescence region not only revealed the heterogeneity of organic matter, but also provided more accurate information on organic matter humification. In addition, the results showed that the PPC model could be used to characterize integrally the humification, and the projected characteristic value calculated from the PPC model could be used as the integrated humification evaluation index.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Laboratory of Water Environmental System Engineering, Chinese Research Academy of Environmental Science, Beijing 100012, China.
authors.forename: Xiao-Song
authors.initials: XS
authors.lastname: He
authors.forename: Bei-Dou
authors.initials: BD
authors.lastname: Xi
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Pan
authors.forename: Da
authors.initials: D
authors.lastname: An
authors.forename: Shuo-Guo
authors.initials: SG
authors.lastname: Bai
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Dong-Yu
authors.initials: DY
authors.lastname: Cui
mesh_terms: D005163:Factor Analysis, Statistical; D005453:Fluorescence; D006812:Humic Substances; D008956:Models, Chemical; D012037:Refuse Disposal; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
keywords: Dissolved organic matter; Excitation–emission matrix (EEM) spectra; Fluorescence regional integration (FRI); Parallel factor analysis (PARAFAC); Projection pursuit cluster (PPC) model