title: Evaluation of the Interactions between Water Extractable Soil Organic Matter and Metal Cations (Cu(II), Eu(III)) Using Excitation-Emission Matrix Combined with Parallel Factor Analysis.
abstract: The objectives of this study were to evaluate the binding behavior of Cu(II) and Eu(III) with water extractable organic matter (WEOM) in soil, and assess the competitive effect of the cations. Excitation-emission matrix (EEM) fluorescence spectrometry was used in combination with parallel factor analysis (PARAFAC) to obtain four WEOM components: fulvic-like, humic-like, microbial degraded humic-like, and protein-like substances. Fluorescence titration experiments were performed to obtain the binding parameters of PARAFAC-derived components with Cu(II) and Eu(III). The conditional complexation stability constants (logKM) of Cu(II) with the four components ranged from 5.49 to 5.94, and the Eu(III) logKM values were between 5.26 to 5.81. The component-specific binding parameters obtained from competitive binding experiments revealed that Cu(II) and Eu(III) competed for the same binding sites on the WEOM components. These results would help understand the molecular binding mechanisms of Cu(II) and Eu(III) with WEOM in soil environment.
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS, 17 Chunhui Road, Yantai 264003, Shandong, China. jwei@yic.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Wei
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, Jiangsu, China. hanlu@issas.ac.cn.
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, Jiangsu, China. jingsong@issas.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, Jiangsu, China. mfchen@issas.ac.cn.
authors.forename: Mengfang
authors.initials: M
authors.lastname: Chen
mesh_terms: D065638:Absorption, Radiation; D003300:Copper / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D006812:Humic Substances; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry
chemical_list: D006812:Humic Substances; D014867:Water; D005063:Europium; D003300:Copper
keywords: copper; europium; excitation-emission matrix; parallel factor analysis; water extractable organic matter