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bound to humic substances by time-resolved laser fluorescence spectroscopy (TRLFS) and parallel factor analysis (PARAFAC)Lukman, S.*; 斉藤 拓巳*; 青柳 登; 木村 貴海; 長崎 晋也*
Geochimica et Cosmochimica Acta, 88, p.199 - 215, 2012/07
被引用回数：24 パーセンタイル：55.25(Geochemistry & Geophysics)The bioavailability and the toxicological properties of metal ions, including radionuclides, in the biosphere are greatly influenced by the speciation. This is especially critical in evaluating the feasibility of nuclear waste disposal where the understanding of radionuclide migration through geosphere from engineering barriers is one of the keys for performance assessment. Organic matters are important constituents of groundwater and have significant impact on the speciation and thus mobility of radionuclides, among which are humic substances (HSs) because of their high affinity to metal ions. In this study, europium (Eu) is used as the chemical homologue of trivalent actinides (An), to understand the speciation of An when it interacts with HSs collected from various origins. TRLFS is used for the speciation study owing to its high sensitivity and selectivity to differentiate multiple species co-existing simultaneously. The interpretation of the Eu species, denoted as Factor A, B and C, was tackled by Principal Component Analysis (PCA) and Partial Linear Square (PLS) Regression to deduce the nature of Eu species formed by taking into account the physicochemical properties of HSs that influence each species luminescence characteristics.
Lukman, S.*; 斉藤 拓巳*; 長崎 晋也*; 木村 貴海
no journal, ,
Combination of Time Resolved Laser Fluorescence Spectroscopy (TRLFS) and Parallel Factor Analysis (PARAFAC) has been demonstrated as a useful method for distinguishing several Eu(III) species coexisted in solution in the presence of humic substances (HS). Despite of classification types (humic and filvic acid), isolation origin, and humification process, there are only 3 factors can be recovered from the investigated system.
with humic substances studied by time-resolved laser fluorescence spectroscopy and parallel factor analysis斎藤 拓巳*; Lukman, S.*; 青柳 登; 木村 貴海; 長崎 晋也*
no journal, ,
Humic substances are heterogeneous and ill-defined organic nanoparticles widely found in soil and aqueous environments. They are known as effective complexants for inorganic and organic contaminants, mediating their migration through geosphere. In this research, we investigated the binding of Eu to various HS by time-resolved laser fluorescence spectroscopy hyphnated with parallel factor analysis. Time-resolved laser fluorescence spectroscopy (TRLFS) is an analytical technique sensitive to physico-chemical forms of a target fluorescent metal ion, which can be further reinforced by combining with a powerful multivariate data analysis, PARARAC. Binding of Eu to HS purchased from the International and Japanese Humic Substances Societies was examined by TRLFS as a function of pH. A series of TRLFS data obtained for a certain HS were processed by PARAFAC to determine the number, spectra, decays and relative concentrations of factors. Each of the factors has some similarity among different HS, suggesting the presence of similar binding environments in different HS. It was further revealed that there were systematic trends between the spectra, decays and concentrations of the factors and the physical and chemical properties of HS. The observed trends will be used to deduce the characteristics of the different binding environments for Eu in HS.
