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Terashima M, Endo T, Kimuro S, Beppu H, Nemoto K, Amano Y. Iron-induced association between selenium and humic substances in groundwater from deep sedimentary formations. J NUCL SCI TECHNOL 2022. [DOI: 10.1080/00223131.2022.2111376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
| | - Takashi Endo
- Japan Nuclear Fuel Chemical Analysis Co., Ltd, Aomori, Japan
| | | | - Hikari Beppu
- Inspection Development Company Ltd, Ibaraki, Japan
| | | | - Yuki Amano
- Japan Atomic Energy Agency (JAEA), Ibaraki, Japan
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Nakano S, Marumo K, Kazami R, Saito T, Haraga T, Tasaki-Handa Y, Saito S. Stoichiometry between Humate Unit Molecules and Metal Ions in Supramolecular Assembly Induced by Cu 2+ and Tb 3+ Measured by Gel Electrophoresis Techniques. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15172-15180. [PMID: 34730943 DOI: 10.1021/acs.est.1c03993] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Humic acid (HA), a fraction of humic substances, can strongly complex with metal ions to form a supramolecular assembly via coordination binding and other intermolecular forces. However, determining the supramolecular size distribution and stoichiometry between small HA unit molecules constituting HA supramolecules and metal ions has proven to be challenging. Here, we investigated the changes in the size distributions of HAs induced by Cu2+ and Tb3+ ions using unique PAGE for the separation and quantification of HA complexes and metal ions bound, followed by UV-vis spectroscopy and excitation-emission matrix-parallel factor analysis. By determining the concentrations of HA and metal ions, it was possible to estimate the stoichiometry of the HA unit molecule to metal ions in supramolecular complexes. It was found that the supramolecular behaviors of Cu2+ and Tb3+ complexes with HA collected from peat (PAHA) and deep groundwater (HHA) differed. For example, two HHA unit molecules form a supramolecule via cross-linking by a Cu2+ ion in the case of Cu2+-HHA. Our results suggest that this supramolecular stoichiometry is related to the abundance of sulfur atoms in the elemental composition of HHA. Our experimental results and analysis provide new insights into HA supramolecules formed via metal complexation.
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Affiliation(s)
- Sumika Nakano
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Kazuki Marumo
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Rintaro Kazami
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Takumi Saito
- Nuclear Professional School, Graduate School of Engineering, The University of Tokyo, 2-21 Shirakata-Shirane, Tokai-mura, Ibaraki 319-1188, Japan
| | - Tomoko Haraga
- Department of Decommissioning and Waste Management, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
| | - Yuiko Tasaki-Handa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Shingo Saito
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
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Sasaki T, Goto R, Saito T, Kobayashi T, Ikuji T, Sugiyama Y. Gamma-ray irradiation impact of humic substances on apparent formation constants with Cu(II). J NUCL SCI TECHNOL 2018. [DOI: 10.1080/00223131.2018.1503573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Takayuki Sasaki
- Department of Nuclear Engineering, Kyoto University, Kyoto, Japan
| | - Ryohei Goto
- Department of Nuclear Engineering, Kyoto University, Kyoto, Japan
| | - Takeshi Saito
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Taishi Kobayashi
- Department of Nuclear Engineering, Kyoto University, Kyoto, Japan
| | - Takagi Ikuji
- Department of Nuclear Engineering, Kyoto University, Kyoto, Japan
| | - Yuko Sugiyama
- Department of Applied Science, Okayama University of Science, Okayama, Japan
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Nouhi A, Hajjoul H, Redon R, Gagné JP, Mounier S. Time-resolved laser fluorescence spectroscopy of organic ligands by europium: Fluorescence quenching and lifetime properties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 193:219-225. [PMID: 29247918 DOI: 10.1016/j.saa.2017.12.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/13/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
Time-resolved Laser Fluorescence Spectroscopy (TRLFS) has proved its usefulness in the fields of biophysics, life science and geochemistry to characterize the fluorescence probe molecule with its chemical environment. The purpose of this study is to demonstrate the applicability of this powerful technique combined with Steady-State (S-S) measurements. A multi-mode factor analysis, in particular CP/PARAFAC, was used to analyze the interaction between Europium (Eu) and Humic substances (HSs) extracted from Saint Lawrence Estuary in Canada. The Saint Lawrence system is a semi-enclosed water stream with connections to the Atlantic Ocean and is an excellent natural laboratory. CP/PARAFAC applied to fluorescence S-S data allows introspecting ligands-metal interactions and the one-site 1:1 modeling gives information about the stability constants. From the spectral signatures and decay lifetimes data given by TRLFS, one can deduce the fluorescence quenching which modifies the fluorescence and discuss its mechanisms. Results indicated a relatively strong binding ability between europium and humic substances samples (LogK value varies from 3.38 to 5.08 at pH 7.00). Using the Stern-Volmer plot, it has been concluded that static and dynamic quenching takes places in the case of salicylic acid and europium interaction while for HSs interaction only a static quenching is observed.
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Affiliation(s)
- A Nouhi
- Laboratoire PROTEE, Université de Toulon, Toulon Cedex 9 CS 60584-83041, France.
| | - H Hajjoul
- Laboratoire PROTEE, Université de Toulon, Toulon Cedex 9 CS 60584-83041, France
| | - R Redon
- Laboratoire PROTEE, Université de Toulon, Toulon Cedex 9 CS 60584-83041, France
| | - J P Gagné
- Institut des sciences de la mer de Rimouski, Université du Québec, Canada
| | - S Mounier
- Laboratoire PROTEE, Université de Toulon, Toulon Cedex 9 CS 60584-83041, France
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