Fundamental Study on Uranyl Coordination With Biological Ligands Analyzed by Herfd-xanes Spectroscopy

Fundamental Study on Uranyl Coordination With Biological Ligands Analyzed by Herfd-xanes Spectroscopy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Fundamental Study on Uranyl Coordination With Biological Ligands Analyzed by Herfd-xanes Spectroscopy Akihiro Uehara, Daiju Matsumura, Daisuke Akiyama, Akira Kirishima, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7673847/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract ABSRACT Uranium has the potential to form complexes with biological ligands in body fluids upon internal exposure. The coordination of U with biological ligands was analyzed by using high energy resolution fluorescence detected X-ray absorption near edge fine structure (HERFD-XANES) at U L 3 edge. A spectra of uranyl compounds such as uranium dioxide, uranyl acetate, carbonate, phosphate, hydroxide, and cysteine were measured by HERFD-XANES spectroscopy. Symmetry of the compounds was discussed on the results of linear combination least-squares fit modeling of the spectra. Pre-edge peak of U(VI) samples in HERFD-XANES spectra were different from those obtained with conventional XANES spectra. It was suggested that uranyl carbonate has the highest symmetry of the uranyl compounds studied. Differences between the shoulder peak of carbonate and that of acetate in the HERFD-XANES were observed, and peak energies in the experimental data were supported by those in the calculated data based on the finite difference method for near-edge structure. This finding suggests that HERFD-XANES can successfully distinguish coordination structure with similar ligands in contrast to conventional XANES. Uranium HERFD- XANES bio-ligands acetate carbonate cysteine FDMNES Figures Figure 1 Figure 2 Figure 3 INTRODUCTION It is fundamental to have knowledge on the distribution and metabolism of radionuclides such as uranium (U) in the event of internal exposure during the process of nuclear decommissioning. The dynamics of actinides and molecular mechanisms in biological fluids have been analyzed using absorption and emission spectroscopy[ 1 ]. Molecular interaction between actinides and biological compounds dissolving in the solutions has been evaluated by X-ray spectroscopy with higher transmittance. We have demonstrated that X-ray absorption near edge fine structure (XANES) can distinguish the chemical structure of U combined with biological ligands in serum from that combined with chelating agents[ 2 ], this distinction offers a new method for assessing the effectiveness of U decorporation. However, coordination of U with ligands such as carbonate and acetate could not be identified clearly based on conventional XANES spectroscopy. Here we focused on high energy resolution fluorescence detected (HERFD)-XANES spectroscopy. In HERFD-XANES, the spectral broadening caused by the core-hole lifetime in conventional XANES is suppressed thereby allowing for the acquisition of XANES spectra with better energy resolution. Since the lifetime width of the U L 3 shell is 7.4–8.2 eV, HERFD-XANES is expected to improve the resolution by about 2 times compared to conventional XANES. Sensitive measurement was attained even at a lower concentration of the objective metal. Recently, there have been remarkable developments in using HERFD-XANES to study the relationship between transition metals and biological compounds [ 3 – 5 ]. Thomas, et al. [ 6 ] showed that HERFD-XANES detected zinc coordination to carboxyl, phosphoryl, imidazole, and/or thiol moieties in model microorganisms. On the other hand, actinide structural studies using HERFD-XANES have been utilized extensively in the last decade [ 7 , 8 ]. The oxidation state of U inorganic compounds revealed on the comparison of HERFD-XANES spectra at the U L 3 edge [ 9 – 18 ]. HERFD-XANES at not U L 3 edge but U M 4 edge of U-organic ligands has been reported by Kohler et al. [ 19 ]. Biological reductions of U(VI) by bacterium were analyzed only based on U M 4 edge of HERFD-XANES [ 20 – 22 ]. Detailed information on electronic transition and elemental valence states have been obtained by further splitting the X-ray fluorescence to distinguish minute structural changes applying to the analysis of the local structure of U coordinated by bio-ligands such as protein. It would be rather difficult to measure spectra of the U M 4 edge (3.5 keV) due to X-ray absorption by air compared to U L 3 edge (17.2 keV) because the radioactive samples containing U should be sealed by films for the contamination control. In the present study, HERFD-XANES spectrum at U L 3 edge of U compounds coordinated by bio-ligands such as acetate, carbonate, phosphate, hydroxide, and cysteine, were measured. Uranyl ion has strong affinity with oxygen atom of the functional group in biological ligands. Cysteine, which has a potential to coordinate with U ions by carboxyl as well as thiol ligands[ 23 , 24 ], was used as a representative of amino acid. This allowed us to analyze the local structure of U which could not be distinguished using conventional XANES spectra. This higher sensitivity of HERFD-XANES leads to the further development in assessing U decorporation. EXPERIMENTAL Chemicals Samples for the HERFD-XANES and conventional XANES measurements were prepared. Uranium dioxide [ 25 ], uranyl hydroxide [ 26 ], uranyl carbonate [ 27 ], and uranyl phosphate [ 28 ] were prepared by the methods previously reported and confirmed by powder X-ray diffractometer (Mini-Flex 600. Rigaku Co.). The uranyl acetate used was purchased from WAKO Chemical LTD. The uranyl cysteine was prepared as follows; uranyl nitrate hexahydrate salt was used as a starting material. 0.1 mL of 1 M uranyl nitrate was then mixed with 1 mL of 1 M cysteine solution which was neutralized with NaOH to pH 7.5. The cysteine used was L-Cysteine (≥ 98%, Sigma-Aldrich Co. LLC). The precipitation was separated from the supernatant containing hydrolysis species. Powder from these samples was obtained through freezing and drying methods. The sample was not identified with the XRD method due to forming amorphous. Uranium samples were prepared at QST and Tohoku university. XANES measurements HERFD-XANES spectra were measured at BL11XU beamline of SPring-8, Japan. A Si(311) double-crystal was used to monochromatize the incident X-ray beam. The X-ray fluorescence (U Lα1 line (13.614 keV)) emitted from the sample was analyzed in energy by three vertically placed Si(880) spherical curved crystals (10 cmφ, crystal spacing 17.5 cm) and then measured with a silicon microstrip detector. The sample, the curved crystal and the detector were all on the same Rowland circle (radius 1 m), and the spherically curved crystal and the silicon microstrip detector were moved on a rotation stage to maximize the intensity of the U Lα1 line (3d 5/2 →2p 3/2 ). The horizontal and vertical beam sizes were 0.8- and 0.3 mm, respectively. The energy resolution was calculated to be 2.7 eV. A step scanning mode, in which a single scan is taken for about a 30 min period, was initially used. Uranium powder was pasted thinly to Kapton tape (35 um thickness, Teraoka Seisakusho Co., Ltd. ) to avoid energy shift due to the shift of luminous center, and the samples were sealed by peek film (6 um thickness, Shin-Etsu Polymer Co., Ltd.). Because the beam damage of the samples (acetate and cysteine) was observed, these spectra were measured under lower brightness using 4 mm aluminum plate (about 0.2%) and no spectrum changing was confirmed during measurements. U L 3 edge X-ray absorption measurements were performed at the beamline BL14B1, SPring-8, Japan. A Si(311) double-crystal was used to monochromatize the incident X-ray beam. The horizontal and vertical beam sizes were 2.6- and 2.2-mm, respectively. A step scanning mode where a single scan is taken for about 30 min, was initially used. All measurements were performed under ambient conditions at room temperature. Data analysis was performed according to a standard procedure using the Demeter software package (version 0.9.18) [ 29 ]. The linear combination least-squares fit modeling of the spectra was performed with the software. The XANES spectra at the U L 3 edge of uranyl acetate dihydrate, and tetrasodium dioxouranate(VI) tricarbonate were simulated utilizing the finite difference method for near-edge structure (FDMNES)[ 30 ]. The code allows the calculation of the occupied and unoccupied projected density of states in relation to the X-ray absorption and emission processes. Simulations were performed using an atomic cluster with 6.0 Å. Relativistic self-consistent field calculations using the Dirac-Slater approach were performed for each atom in the considered cluster. The Poisson equation was solved by the superposed self-consistent atomic densities in the selected cluster which were used to obtain the Coulomb potential. Full multiple scattering theory simulations were performed to obtain the simulated XANES spectra. Spin − orbit effects were taken into account in the calculations due to the presence of heavy nuclei (U). Calculations were performed on bases of 2p 3/2 →5f transitions with no experimental broadening. The FDMNES calculations of uranyl acetate dihydrate, and tetrasodium dioxouranate(VI) tricarbonate were shifted down by 5.1 eV with respect to the experimental energy position to compare with the experimental spectra. RESULTS AND DISCUSSION The conventional XANES spectra collected in transmission mode is shown in Fig. 1 (a). The XANES spectrum of UO 2 is composed of one intense peak, with the so-called white line situated at 17.172 keV, and an additional resonance at higher energy around 17.211 keV. The inflection point E 0 has been found around 17167 eV. The white line corresponds to the electric transition from U 2p 3/2 to unoccupied U 6d. HERFD-XANES of UO 2 showed more significant peaks when compared with conventional-XANES (Fig. 1 (b)). The peak at 17.190 keV in HERFD-XANES was not observed in conventional-XANES. UO 2 is a semiconductor with a cubic fluorite structure and 5f2 valence configuration. The U atoms are surrounded by eight O atoms at a distance of 2.3678 Å. Linear combination analysis of the spectrum was performed assuming that the spectrum was consisted of three electric transitions. Energy, height, and Full Width at Half Maximum (FWHM) of the peak were calculated. The FWHM at the white line of HERFD-XANES showed narrow compared with conventional XANES as previously reported [ 9 , 15 , 18 ]. Conventional XANES and HERFD-XANES of uranyl acetate, carbonate, phosphate, hydroxide, and cysteine complexes were measured shown in Fig. 1 (a) and (b), respectively. White line energy of uranyl compounds was higher than that of UO 2 as U(IV) shown in conventional XANES as well as HERFD-XANES. Linear combination analysis of the spectrum was performed, assuming it consisted of three electric transitions: a pre-edge peak (peak A), a main peak (peak B), and a shoulder peak (peak C). Fitting curve was plotted in Fig. 2 . Energy, height, and Full Width at Half Maximum (FWHM) of the peak were calculated and shown in Table 1 . The FWHM of the white line in HERFD-XANES in Table 1 was obviously smaller than that in conventional XANES. A clear peak at 17.173 keV (peak B) resulted in the clear recognition of these complexes. Furthermore, the pre-edge peak in HERFD-XANES at 17.166 keV (peak A), which was not shown in conventional XANES, was observed. It has been reported that the pre-edge peak corresponds to quadrupole transition from the 2p 3/2 to 5f orbital by U 5f – O 2p orbital mixing based on the calculated density of states (DOS) [ 9 , 12 ]. The FWHM of the pre-edge peak (peak A) and the white line (peak B) of carbonate complex were narrower than that of the other complexes resulted in clear peak of the pre-edge (peak A). This means that coordination symmetry of the complex depends on the FWHM of the white line of the XANES spectrum. While the white line energy of these complex of U(VI) was remarkably different from that of UO 2 of U(IV), it can be also sensitive to any changes in symmetry, type of axial, equatorial ligands, or the bonding character of the given compounds. Optimization with spectra obtained from known compounds is required to confirm the use of this feature for determination of unknown U compounds [ 12 ]. Table 1 Height, position, and FWHM parameters of the fitting HERFD-XANES spectra of uranyl compounds (uranyl acetate, carbonate, phosphate, hydroxide, and cysteine). The linear combination fitting based on Gauss and step functions of a pre-edge peak (peak A), a main peak (peak B) and a shoulder peak (peak C) shown in Fig. 2 . peak Position (keV) Height (a.u.) FWHM (eV) Uranyl acetate A 17.1672 0.2381 5.45* B 17.1736 1.7445 C 17.1866 0.1346 11.55 Uranyl carbonate A 17.1664 0.2104 5.17* B 17.1734 1.7486 C 17.1838 0.2240 13.85 Uranyl phosphate A 17.1662 0.1908 5.92* B 17.1732 1.5682 C 17.1856 0.2423 16.61 Uranyl hydroxide A 17.1662 0.2026 5.62* B 17.1731 1.3683 C 17.1828 0.3568 16.20 Uranyl cysteine A 17.1667 0.2277 5.53* B 17.1733 1.6630 C 17.1860 0.2177 12.29 *FWHM of peak A was assumed to be same as that of peak B. The spectrum of uranyl carbonate was compared with that of uranyl acetate, which was representative of complexes such as bidentate carboxy or carbonate ligands. Shoulder peak in the HERFD-XANES spectrum of uranyl carbonate was clearly observed than that of uranyl acetate though the difference of two compounds in conventional XANES spectrum was also observed (Fig. 3 top). It was hard to compare the pre-edge peak of two compounds in HERFD-XANES spectrum because of the low SB. The shoulder peak of carbonate complex calculated by FDMNES was observed at lower energy than that of acetate complex, and also its peak intensity of carbonate complex was higher than that of acetate complex, indicating the experimental data is supported by calculated data shown in Fig. 3 bottom. HERFD-XANES spectra of uranyl cysteine complex was compared with that of uranyl acetate, carbonate, phosphate, and hydroxide complexes. Remarkable differences of the shoulder peak in HERFD-XANES were observed compared with uranyl acetate, which is same carboxyl group coordinating to U, though the shape as observed through the conventional XANES as well as EXAFS spectra were quite resemble. The spectrum of uranyl cysteine is distinguished from the spectra of uranyl carbonate and hydroxide indicating that uranyl cysteine does not contain carbonate and hydroxide compounds. It has been reported that cysteine forms complex with U via the thiol group in addition to the carboxylic group in cysteine at lower pH [ 23 , 24 ]. Though it is suggested that carboxyl group in cysteine coordinates to U in the present sample prepared, further study would be necessary to distinguish the coordination of carboxylate and thiolate. CONCLUSION HERFD-XANES spectra of U samples, uranyl dioxide, uranyl acetate, carbonate, hydroxide, phosphate, and cysteine were measured. The pre-edge peak was observed for U(VI) compounds which is affected by the FWHM of the white line peak. It was suggested that uranyl carbonate has the highest symmetry of the uranyl compounds studied. Differences between the shoulder peak of carbonate and that of acetate in the experimental data were supported by those in the FDMNES. This finding suggests that HERFD-XANES can distinguish coordination structure of U with similar ligands in contrast to conventional XANES. This approach would pave the way for future studies on the analysis of the ligand exchange as well as the reduction of U in biological fluids, thereby improving the assessment of U decorporation. Declarations Author Contribution Akihiro Uehara: conceptualization, methodology, formal analysis, investigation, writing – original draft, visualization. Daiju Matsumura: methodology, investigation. writing – review and editing.Daisuke Akiyama: investigation, methodologyAkira Kirishima, investigation, writing – review and editing.Shino Homma-Takeda: writing –review and editing, funding acquisition.Teruaki Konishi: writing –review and editing, project administration.Takumi Yomogida, methodology, investigation, formal analysis.Kenji Ishii: methodology, investigation, resources, writing – review and editing, supervision. Acknowledgement We thank Dr. Takuya Tsuji (Materials Sciences Research Center, Japan Atomic Energy Agency) and Dr. Ayumi Shiro (Synchrotron Radiation Research Center, QST) for technical supports of XAFS measurements at BL14B1 line. We also thank Mr. Yoshinari Shiino and Mr. Kohei Iwaya (Department of Safety Administration, QST) for their assistance of the experimental procedure including the nuclear fuel materials. A.U. thanks Prof. Hisashi Hayashi (Japan Women's University) for useful suggestions and constructive comments on the manuscript. X-ray absorption measurements were performed at the beamline BL11XU and BL14B1, SPring-8, Japan, based on the proposal Nos. 2023B3557, 2024A3557, 2024B3557 for BL11XU and Nos. 2022A3662, 2022B3662, 2023A3662, 2023B3662, 2024A3662, 2024B3662, 2025A3662 for BL14B1, respectively. This work was performed under the Cooperative Research Program of “Network Joint Research Center for Materials and Devices (MEXT).” This work was supported by JSPS KAKENHI Grant Numbers 19H05775 and 20K05391. References Denecke MA (2024) Synchrotron investigations in environmental radiochemistry research. J Radioanal Nucl Ch Uehara A, Matsumura D, Tsuji T, Yakumaru H, Tanaka I, Shiro A, Saitoh H, Ishihara H (2022) Homma-Takeda, Uranium chelating ability of decorporation agents in serum evaluated by X-ray absorption spectroscopy. Anal Methods 14:2439–2445 Kowalska JK, Lima FA, Pollock CJ, Rees JA, DeBeer S (2016) A Practical Guide to High-resolution X-ray Spectroscopic Measurements and their Applications in Bioinorganic Chemistry. Isr J Chem 56:803–815 Proux O, Lahera E, Net WD, Kieffer I, Rovezzi M, Testemale D, Irar M, Thomas S, Aguilar-Tapia A, Bazarkina EF, Prat A, Tella M, Auffan M, Rose J, Hazemann JL (2017) High-Energy Resolution Fluorescence Detected X-Ray Absorption Spectroscopy: A Powerful New Structural Tool in Environmental Biogeochemistry Sciences. J Environ Qual 46:1146–1157 Buzanich AG (2022) Recent developments of X-ray absorption spectroscopy as analytical tool for biological and biomedical applications. X-Ray Spectrom 51:294–303 Thomas SA, Mishra B, Myneni SCB (2019) High Energy Resolution-X-ray Absorption Near Edge Structure Spectroscopy Reveals Zn Ligation in Whole Cell Bacteria. J Phys Chem Lett 10:2585–2592 Kvashnina KO, Butorin SM (2022) High-energy resolution X-ray spectroscopy at actinide M4,5 and ligand K edges: what we know, what we want to know, and what we can know. Chem Commun 58:327–342 Caciuffo R, Lander GH, van der Laan G (2023) Synchrotron radiation techniques and their application to actinide materials. Rev Mod Phys, 95 Vitova T, Kvashnina KO, Nocton G, Sukharina G, Denecke MA, Butorin SM, Mazzanti M, Caciuffo R, Soldatov A, Behrends T, Geckeis H (2010) High energy resolution x-ray absorption spectroscopy study of uranium in varying valence states. Phys Rev B, 82 Vitova T, Green JC, Denning RG, Löble M, Kvashnina K, Kas JJ, Jorissen K, Rehr JJ, Malcherek T, Denecke MA (2015) Polarization Dependent High Energy Resolution X-ray Absorption Study of Dicesium Uranyl Tetrachloride. Inorg Chem 54:174–182 LLorens I, Solari PL, Sitaud B, Bes R, Cammelli S, Hermange H, Othmane G, Safi S, Moisy P, Wahu S, Bresson C, Schlegel ML, Menut D, Bechade JL, Martin P, Hazemann JL, Proux O (2014) Den Auwer, X-ray absorption spectroscopy investigations on radioactive matter using MARS beamline at SOLEIL synchrotron. Radiochim Acta 102:957–972 Bes R, Rivenet M, Solari PL, Kvashnina KO, Scheinost AC, Martin PM (2016) Use of HERFD-XANES at the U L3- and M4-Edges To Determine the Uranium Valence State on [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3]. Inorg Chem 55:4260–4270 Dewey C, Sokaras D, Kroll T, Bargar JR, Fendorf S (2020) Calcium-Uranyl-Carbonato Species Kinetically Limit U(VI) Reduction by Fe(II) and Lead to U(V)-Bearing Ferrihydrite. Environ Sci Technol 54:6021–6030 Kawamura N, Hirose Y, Honda F, Shimokasa R, Ishimatsu N, Mizumaki M, Kawaguchi SI, Hirao N, Mimura K (2020) Study on the Correlation of U Valence States with U–U Distance in UPd2Cd20, in: Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019) Leinders G, Bes R, Kvashnina KO, Verwerft M (2020) Local Structure in U(IV) and U(V) Environments: The Case of U3O7. Inorg Chem 59:4576–4587 Hunault MOJY, Menut D, Tougait O (2021) Alkali Uranyl Borates: Bond Length, Equatorial Coordination and 5f States, vol 11. Crystals Bes R, Leinders G, Kvashnina K (2022) Application of multi-edge HERFD-XAS to assess the uranium valence electronic structure in potassium uranate (KUO3). J Synchrotron Radiat 29:21–29 Yomogida T, Akiyama D, Ouchi K, Kumagai Y, Higashi K, Kitatsuji Y, Kirishima A, Kawamura N, Takahashi Y (2022) Application of High-Energy-Resolution X-ray Absorption Spectroscopy at the U L3-Edge to Assess the U(V) Electronic Structure in FeUO4. Inorg Chem 61:20206–20210 Köhler L, Patzschke M, Bauters S, Vitova T, Butorin SM, Kvashnina KO, Schmidt M, Stumpf T, März J (2022) Insights into the Electronic Structure of a U(IV) Amido and U(V) Imido Complex. Chem-Eur J, 28 Vettese GF, Morris K, Natrajan LS, Shaw S, Vitova T, Galanzew J, Jones DL, Lloyd JR (2020) Multiple Lines of Evidence Identify U(V) as a Key Intermediate during U(VI) Reduction by Shewanella oneidensis MR1. Environ Sci Technol 54:2268–2276 Molinas M, Faizova R, Brown A, Galanzew J, Schacherl B, Bartova B, Meibom KL, Vitova T, Mazzanti M (2021) Bernier-Latmani, Biological Reduction of a U(V)-Organic Ligand Complex. Environ Sci Technol 55:4753–4761 Hilpmann S, Rossberg A, Steudtner R, Drobot B, Hubner R, Bok F, Prieur D, Bauters S, Kvashnina KO, Stumpf T, Cherkouk A (2023) Presence of uranium(V) during uranium(VI) reduction by Desulfosporosinus hippei DSM 8344(T). Sci Total Environ 875:162593 Günther A, Geipel G, Bernhard G (2007) Complex formation of uranium(VI) with the amino acids l-glycine and l-cysteine: A fluorescence emission and UV–Vis absorption study. Polyhedron 26:59–65 Kirishima A, Takei M, Uehara A, Akiyama D (2025) Determination of the thermodynamic quantities for complex formation of U(VI) with amino acids in aqueous solution. J Chem Thermodyn, 206 Uehara A, Akiyama D, Ikeda-Ohno A, Numako C, Terada Y, Nitta K, Ina T, Homma-Takeda S, Kirishima A, Sato N (2022) Speciation on the reaction of uranium and zirconium oxides treated under oxidizing and reducing atmospheres. J Nucl Mater 559:153422 Kirkegaard MC, Spano TL, Ambrogio MW, Niedziela JL, Miskowiec A, Shields AE, Anderson BB (2019) Formation of a uranyl hydroxide hydrate hydration of [(UOF)(HO)]•4HO. Dalton Trans 48:13685–13698 Gurzhiy VV, Kalashnikova SA, Kuporev IV, Plasil J (2021) Crystal Chemistry and Structural Complexity of the Uranyl Carbonate Minerals and Synthetic Compounds, Crystals, 11 Foster RI, Kim KW, Lee KY (2020) Uranyl phosphate (MUOPO) precipitation for uranium sequestering: formation and physicochemical characterisation. J Radioanal Nucl Ch 324:1265–1273 Ravel B, Newville M, ARTEMIS ATHENA (2005) HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. J Synchrotron Radiat 12:537–541 Joly Y (2001) X-ray absorption near-edge structure calculations beyond the muffin-tin approximation. Phys Rev B, 63 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7673847","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":522087032,"identity":"e1d87688-dfd5-4712-b221-370d515f087f","order_by":0,"name":"Akihiro Uehara","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYFACHgglwczDcICBwQYmzEa0ljSYYmK0QBiH8SsGAYPjvQc/V9QwyEu28x48XFFxXnb+/AbmFx8Y+PJwajlzLlnyzDEGw9nMfAkHz5y5bbzhGAOb5QwGtmKcWm7kGEg2sDEwzmPmMTjY2HY7cQMbA5sxDwNbYgMuLfffGP9s+MdgD9VyLnF+GyEtN3jMJBvbGBJnQ7QcSGw4xsD8GJ8WyTM5ZpaNfRLJM5uBWhrOJAP9ktjGOMMAt1/4jp8xvtnwzcZ2xvkzxh8bKuxk5zcfPvzhQ8UxnCEGBRJwFmMDA2ObBIPBsQQCWhAAqIWB+QMDQw3xWkbBKBgFo2C4AwD3R1c8UIxdPQAAAABJRU5ErkJggg==","orcid":"","institution":"National Institutes for Quantum Science and Technology (QST)","correspondingAuthor":true,"prefix":"","firstName":"Akihiro","middleName":"","lastName":"Uehara","suffix":""},{"id":522087035,"identity":"5bb2533e-2b4f-4ad0-9290-ab10ad8fac1e","order_by":1,"name":"Daiju Matsumura","email":"","orcid":"","institution":"Japan Atomic Energy Agency","correspondingAuthor":false,"prefix":"","firstName":"Daiju","middleName":"","lastName":"Matsumura","suffix":""},{"id":522087038,"identity":"0de189fe-f4b1-49ce-9405-e4b30de4b77b","order_by":2,"name":"Daisuke Akiyama","email":"","orcid":"","institution":"Tohoku University","correspondingAuthor":false,"prefix":"","firstName":"Daisuke","middleName":"","lastName":"Akiyama","suffix":""},{"id":522087040,"identity":"018ef1f3-4efb-4513-adab-0b2081e79dcc","order_by":3,"name":"Akira Kirishima","email":"","orcid":"","institution":"Tohoku University","correspondingAuthor":false,"prefix":"","firstName":"Akira","middleName":"","lastName":"Kirishima","suffix":""},{"id":522087041,"identity":"cf80ecef-dec9-4682-8392-974f1e8e5eab","order_by":4,"name":"Shino Homma-Takeda","email":"","orcid":"","institution":"National Institutes for Quantum Science and Technology (QST)","correspondingAuthor":false,"prefix":"","firstName":"Shino","middleName":"","lastName":"Homma-Takeda","suffix":""},{"id":522087042,"identity":"c70f00f6-aad7-459d-b48b-8bc2500e373d","order_by":5,"name":"Teruaki Konishi","email":"","orcid":"","institution":"National Institutes for Quantum Science and Technology (QST)","correspondingAuthor":false,"prefix":"","firstName":"Teruaki","middleName":"","lastName":"Konishi","suffix":""},{"id":522087043,"identity":"820eb421-e4d4-42c2-ac7f-bb01df541004","order_by":6,"name":"Takumi Yomogida","email":"","orcid":"","institution":"Japan Atomic Energy Agency","correspondingAuthor":false,"prefix":"","firstName":"Takumi","middleName":"","lastName":"Yomogida","suffix":""},{"id":522087044,"identity":"93ed398d-b45f-44aa-a1b1-c936aa658aed","order_by":7,"name":"Kenji Ishii","email":"","orcid":"","institution":"National Institutes for Quantum Science and Technology (QST)","correspondingAuthor":false,"prefix":"","firstName":"Kenji","middleName":"","lastName":"Ishii","suffix":""}],"badges":[],"createdAt":"2025-09-22 11:53:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7673847/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7673847/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":93175730,"identity":"ba7ff606-ee9d-4fb8-a3f2-489e6b8642ca","added_by":"auto","created_at":"2025-10-09 21:07:43","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":331615,"visible":true,"origin":"","legend":"","description":"","filename":"UHERFD20250920finMS1.docx","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/5c85a3595fcbb9e242061bda.docx"},{"id":93175656,"identity":"c5a44377-afbc-49e1-bfc0-42d24f7a5a5d","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9739,"visible":true,"origin":"","legend":"","description":"","filename":"295c5ff17e97413caa68499bbe489c55.json","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/cc0073a5d7662e882bb23f3b.json"},{"id":93175731,"identity":"68b2436f-e40d-4910-874a-dc65f50c872c","added_by":"auto","created_at":"2025-10-09 21:07:43","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":83260,"visible":true,"origin":"","legend":"","description":"","filename":"295c5ff17e97413caa68499bbe489c551enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/53d1b964774a78548c4b00a4.xml"},{"id":93175660,"identity":"adee6054-a768-490c-a575-3ab3fb82764c","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":245650,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/5db660aafb9d078cc417b4ec.png"},{"id":93175657,"identity":"97a88058-ebcf-4b2c-ba0c-34fa32c20280","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":78485,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/f0eef1a75cfe131a2fe24b1c.png"},{"id":93175662,"identity":"d6e199b4-6aae-49d0-aacd-a940ada63530","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":59496,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/fafc4a0ef243f48e03d47cd3.png"},{"id":93175732,"identity":"9eedde80-89ab-42a3-a36a-dee8c1de8c65","added_by":"auto","created_at":"2025-10-09 21:07:43","extension":"xml","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":81216,"visible":true,"origin":"","legend":"","description":"","filename":"295c5ff17e97413caa68499bbe489c551structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/6531fc6478627e811e71fd98.xml"},{"id":93175665,"identity":"7d7ec272-d34e-4c90-afc1-2e8af90e0fa9","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"html","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":90403,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/4865b9b11080504be8691806.html"},{"id":93175659,"identity":"099dbaa8-0321-47a1-bad5-7d84225249ce","added_by":"auto","created_at":"2025-10-09 20:59:43","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":516813,"visible":true,"origin":"","legend":"\u003cp\u003eNormalized (a) Conventional-XANES and (b) HERFD-XANES of U compounds (uranium dioxide, uranyl acetate, carbonate, phosphate, hydroxide, and cysteine).\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/2189a5d62203f241b7d36355.jpeg"},{"id":93176148,"identity":"75e9e44e-15ec-4098-98d7-c2968910b548","added_by":"auto","created_at":"2025-10-09 21:15:43","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":338479,"visible":true,"origin":"","legend":"\u003cp\u003eLinear combination fitting of HERFD-XANES of U compounds (uranyl acetate, carbonate, phosphate, hydroxide, and cysteine) based on Gauss and step functions of a pre-edge peak (peak A), a main peak (peak B) and a shoulder peak (peak C). Solid line: experimental data, dotted line: fitting data.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/d2bdf233b4a6d340f98e51d6.jpeg"},{"id":93175733,"identity":"e5e20708-523a-4960-a74f-ed0958ad0294","added_by":"auto","created_at":"2025-10-09 21:07:43","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":267828,"visible":true,"origin":"","legend":"\u003cp\u003eHERFD-XANES and FDMNES of U carbonate and acetate compounds. Top: HERFD-XANES, button: FDMNES, solid line: uranyl acetate, dotted line: uranyl carbonate.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/d4414fc1bf56acdd3ffb54d0.jpeg"},{"id":103766815,"identity":"3befdf57-7691-475d-977a-766e80a06a01","added_by":"auto","created_at":"2026-03-02 16:16:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1534455,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7673847/v1/f7509945-e033-4a51-a01f-318ce6810e99.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eFundamental Study on Uranyl Coordination With Biological Ligands Analyzed by Herfd-xanes Spectroscopy\u003c/p\u003e","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eIt is fundamental to have knowledge on the distribution and metabolism of radionuclides such as uranium (U) in the event of internal exposure during the process of nuclear decommissioning. The dynamics of actinides and molecular mechanisms in biological fluids have been analyzed using absorption and emission spectroscopy[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Molecular interaction between actinides and biological compounds dissolving in the solutions has been evaluated by X-ray spectroscopy with higher transmittance. We have demonstrated that X-ray absorption near edge fine structure (XANES) can distinguish the chemical structure of U combined with biological ligands in serum from that combined with chelating agents[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], this distinction offers a new method for assessing the effectiveness of U decorporation. However, coordination of U with ligands such as carbonate and acetate could not be identified clearly based on conventional XANES spectroscopy. Here we focused on high energy resolution fluorescence detected (HERFD)-XANES spectroscopy. In HERFD-XANES, the spectral broadening caused by the core-hole lifetime in conventional XANES is suppressed thereby allowing for the acquisition of XANES spectra with better energy resolution. Since the lifetime width of the U L\u003csub\u003e3\u003c/sub\u003e shell is 7.4\u0026ndash;8.2 eV, HERFD-XANES is expected to improve the resolution by about 2 times compared to conventional XANES. Sensitive measurement was attained even at a lower concentration of the objective metal. Recently, there have been remarkable developments in using HERFD-XANES to study the relationship between transition metals and biological compounds [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Thomas, et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] showed that HERFD-XANES detected zinc coordination to carboxyl, phosphoryl, imidazole, and/or thiol moieties in model microorganisms. On the other hand, actinide structural studies using HERFD-XANES have been utilized extensively in the last decade [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The oxidation state of U inorganic compounds revealed on the comparison of HERFD-XANES spectra at the U L\u003csub\u003e3\u003c/sub\u003e edge [\u003cspan additionalcitationids=\"CR10 CR11 CR12 CR13 CR14 CR15 CR16 CR17\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. HERFD-XANES at not U L\u003csub\u003e3\u003c/sub\u003e edge but U M\u003csub\u003e4\u003c/sub\u003e edge of U-organic ligands has been reported by Kohler et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Biological reductions of U(VI) by bacterium were analyzed only based on U M\u003csub\u003e4\u003c/sub\u003e edge of HERFD-XANES [\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Detailed information on electronic transition and elemental valence states have been obtained by further splitting the X-ray fluorescence to distinguish minute structural changes applying to the analysis of the local structure of U coordinated by bio-ligands such as protein. It would be rather difficult to measure spectra of the U M\u003csub\u003e4\u003c/sub\u003e edge (3.5 keV) due to X-ray absorption by air compared to U L\u003csub\u003e3\u003c/sub\u003e edge (17.2 keV) because the radioactive samples containing U should be sealed by films for the contamination control.\u003c/p\u003e\u003cp\u003eIn the present study, HERFD-XANES spectrum at U L\u003csub\u003e3\u003c/sub\u003e edge of U compounds coordinated by bio-ligands such as acetate, carbonate, phosphate, hydroxide, and cysteine, were measured. Uranyl ion has strong affinity with oxygen atom of the functional group in biological ligands. Cysteine, which has a potential to coordinate with U ions by carboxyl as well as thiol ligands[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], was used as a representative of amino acid. This allowed us to analyze the local structure of U which could not be distinguished using conventional XANES spectra. This higher sensitivity of HERFD-XANES leads to the further development in assessing U decorporation.\u003c/p\u003e"},{"header":"EXPERIMENTAL","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eChemicals\u003c/h2\u003e\u003cp\u003eSamples for the HERFD-XANES and conventional XANES measurements were prepared. Uranium dioxide [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], uranyl hydroxide [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], uranyl carbonate [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], and uranyl phosphate [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] were prepared by the methods previously reported and confirmed by powder X-ray diffractometer (Mini-Flex 600. Rigaku Co.). The uranyl acetate used was purchased from WAKO Chemical LTD. The uranyl cysteine was prepared as follows; uranyl nitrate hexahydrate salt was used as a starting material. 0.1 mL of 1 M uranyl nitrate was then mixed with 1 mL of 1 M cysteine solution which was neutralized with NaOH to pH 7.5. The cysteine used was L-Cysteine (\u0026ge;\u0026thinsp;98%, Sigma-Aldrich Co. LLC). The precipitation was separated from the supernatant containing hydrolysis species. Powder from these samples was obtained through freezing and drying methods. The sample was not identified with the XRD method due to forming amorphous. Uranium samples were prepared at QST and Tohoku university.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eXANES measurements\u003c/h3\u003e\n\u003cp\u003eHERFD-XANES spectra were measured at BL11XU beamline of SPring-8, Japan. A Si(311) double-crystal was used to monochromatize the incident X-ray beam. The X-ray fluorescence (U Lα1 line (13.614 keV)) emitted from the sample was analyzed in energy by three vertically placed Si(880) spherical curved crystals (10 cmφ, crystal spacing 17.5 cm) and then measured with a silicon microstrip detector. The sample, the curved crystal and the detector were all on the same Rowland circle (radius 1 m), and the spherically curved crystal and the silicon microstrip detector were moved on a rotation stage to maximize the intensity of the U Lα1 line (3d\u003csub\u003e5/2\u003c/sub\u003e\u0026rarr;2p\u003csub\u003e3/2\u003c/sub\u003e). The horizontal and vertical beam sizes were 0.8- and 0.3 mm, respectively. The energy resolution was calculated to be 2.7 eV. A step scanning mode, in which a single scan is taken for about a 30 min period, was initially used. Uranium powder was pasted thinly to Kapton tape (35 um thickness, Teraoka Seisakusho Co., Ltd. ) to avoid energy shift due to the shift of luminous center, and the samples were sealed by peek film (6 um thickness, Shin-Etsu Polymer Co., Ltd.). Because the beam damage of the samples (acetate and cysteine) was observed, these spectra were measured under lower brightness using 4 mm aluminum plate (about 0.2%) and no spectrum changing was confirmed during measurements.\u003c/p\u003e\u003cp\u003eU L\u003csub\u003e3\u003c/sub\u003e edge X-ray absorption measurements were performed at the beamline BL14B1, SPring-8, Japan. A Si(311) double-crystal was used to monochromatize the incident X-ray beam. The horizontal and vertical beam sizes were 2.6- and 2.2-mm, respectively. A step scanning mode where a single scan is taken for about 30 min, was initially used.\u003c/p\u003e\u003cp\u003eAll measurements were performed under ambient conditions at room temperature.\u003c/p\u003e\u003cp\u003eData analysis was performed according to a standard procedure using the Demeter software package (version 0.9.18) [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. The linear combination least-squares fit modeling of the spectra was performed with the software.\u003c/p\u003e\u003cp\u003eThe XANES spectra at the U L\u003csub\u003e3\u003c/sub\u003e edge of uranyl acetate dihydrate, and tetrasodium dioxouranate(VI) tricarbonate were simulated utilizing the finite difference method for near-edge structure (FDMNES)[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The code allows the calculation of the occupied and unoccupied projected density of states in relation to the X-ray absorption and emission processes. Simulations were performed using an atomic cluster with 6.0 \u0026Aring;. Relativistic self-consistent field calculations using the Dirac-Slater approach were performed for each atom in the considered cluster. The Poisson equation was solved by the superposed self-consistent atomic densities in the selected cluster which were used to obtain the Coulomb potential. Full multiple scattering theory simulations were performed to obtain the simulated XANES spectra. Spin\u0026thinsp;\u0026minus;\u0026thinsp;orbit effects were taken into account in the calculations due to the presence of heavy nuclei (U). Calculations were performed on bases of 2p\u003csub\u003e3/2\u003c/sub\u003e\u0026rarr;5f transitions with no experimental broadening. The FDMNES calculations of uranyl acetate dihydrate, and tetrasodium dioxouranate(VI) tricarbonate were shifted down by 5.1 eV with respect to the experimental energy position to compare with the experimental spectra.\u003c/p\u003e"},{"header":"RESULTS AND DISCUSSION","content":"\u003cp\u003eThe conventional XANES spectra collected in transmission mode is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e1\u003c/span\u003e (a). The XANES spectrum of UO\u003csub\u003e2\u003c/sub\u003e is composed of one intense peak, with the so-called white line situated at 17.172 keV, and an additional resonance at higher energy around 17.211 keV. The inflection point \u003cem\u003eE\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e has been found around 17167 eV. The white line corresponds to the electric transition from U 2p\u003csub\u003e3/2\u003c/sub\u003e to unoccupied U 6d. HERFD-XANES of UO\u003csub\u003e2\u003c/sub\u003e showed more significant peaks when compared with conventional-XANES (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e1\u003c/span\u003e (b)). The peak at 17.190 keV in HERFD-XANES was not observed in conventional-XANES. UO\u003csub\u003e2\u003c/sub\u003e is a semiconductor with a cubic fluorite structure and 5f2 valence configuration. The U atoms are surrounded by eight O atoms at a distance of 2.3678 \u0026Aring;. Linear combination analysis of the spectrum was performed assuming that the spectrum was consisted of three electric transitions. Energy, height, and Full Width at Half Maximum (FWHM) of the peak were calculated. The FWHM at the white line of HERFD-XANES showed narrow compared with conventional XANES as previously reported [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eConventional XANES and HERFD-XANES of uranyl acetate, carbonate, phosphate, hydroxide, and cysteine complexes were measured shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e1\u003c/span\u003e (a) and (b), respectively. White line energy of uranyl compounds was higher than that of UO\u003csub\u003e2\u003c/sub\u003e as U(IV) shown in conventional XANES as well as HERFD-XANES. Linear combination analysis of the spectrum was performed, assuming it consisted of three electric transitions: a pre-edge peak (peak A), a main peak (peak B), and a shoulder peak (peak C). Fitting curve was plotted in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Energy, height, and Full Width at Half Maximum (FWHM) of the peak were calculated and shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The FWHM of the white line in HERFD-XANES in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e was obviously smaller than that in conventional XANES. A clear peak at 17.173 keV (peak B) resulted in the clear recognition of these complexes. Furthermore, the pre-edge peak in HERFD-XANES at 17.166 keV (peak A), which was not shown in conventional XANES, was observed. It has been reported that the pre-edge peak corresponds to quadrupole transition from the 2p\u003csub\u003e3/2\u003c/sub\u003e to 5f orbital by U 5f \u0026ndash; O 2p orbital mixing based on the calculated density of states (DOS) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The FWHM of the pre-edge peak (peak A) and the white line (peak B) of carbonate complex were narrower than that of the other complexes resulted in clear peak of the pre-edge (peak A). This means that coordination symmetry of the complex depends on the FWHM of the white line of the XANES spectrum. While the white line energy of these complex of U(VI) was remarkably different from that of UO\u003csub\u003e2\u003c/sub\u003e of U(IV), it can be also sensitive to any changes in symmetry, type of axial, equatorial ligands, or the bonding character of the given compounds. Optimization with spectra obtained from known compounds is required to confirm the use of this feature for determination of unknown U compounds [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eHeight, position, and FWHM parameters of the fitting HERFD-XANES spectra of uranyl compounds (uranyl acetate, carbonate, phosphate, hydroxide, and cysteine). The linear combination fitting based on Gauss and step functions of a pre-edge peak (peak A), a main peak (peak B) and a shoulder peak (peak C) shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003epeak\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePosition (keV)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHeight (a.u.)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eFWHM (eV)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eUranyl acetate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1672\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2381\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e5.45*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1736\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.7445\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1866\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.1346\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e11.55\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eUranyl carbonate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1664\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2104\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e5.17*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1734\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.7486\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1838\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2240\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e13.85\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eUranyl phosphate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1662\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.1908\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e5.92*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1732\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.5682\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1856\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2423\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e16.61\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eUranyl hydroxide\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1662\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2026\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e5.62*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1731\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.3683\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1828\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.3568\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e16.20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eUranyl cysteine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1667\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2277\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e5.53*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1733\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.6630\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e17.1860\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2177\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e12.29\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e*FWHM of peak A was assumed to be same as that of peak B.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe spectrum of uranyl carbonate was compared with that of uranyl acetate, which was representative of complexes such as bidentate carboxy or carbonate ligands. Shoulder peak in the HERFD-XANES spectrum of uranyl carbonate was clearly observed than that of uranyl acetate though the difference of two compounds in conventional XANES spectrum was also observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e3\u003c/span\u003e top). It was hard to compare the pre-edge peak of two compounds in HERFD-XANES spectrum because of the low SB. The shoulder peak of carbonate complex calculated by FDMNES was observed at lower energy than that of acetate complex, and also its peak intensity of carbonate complex was higher than that of acetate complex, indicating the experimental data is supported by calculated data shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e3\u003c/span\u003e bottom.\u003c/p\u003e\u003cp\u003eHERFD-XANES spectra of uranyl cysteine complex was compared with that of uranyl acetate, carbonate, phosphate, and hydroxide complexes. Remarkable differences of the shoulder peak in HERFD-XANES were observed compared with uranyl acetate, which is same carboxyl group coordinating to U, though the shape as observed through the conventional XANES as well as EXAFS spectra were quite resemble. The spectrum of uranyl cysteine is distinguished from the spectra of uranyl carbonate and hydroxide indicating that uranyl cysteine does not contain carbonate and hydroxide compounds. It has been reported that cysteine forms complex with U via the thiol group in addition to the carboxylic group in cysteine at lower pH [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Though it is suggested that carboxyl group in cysteine coordinates to U in the present sample prepared, further study would be necessary to distinguish the coordination of carboxylate and thiolate.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eHERFD-XANES spectra of U samples, uranyl dioxide, uranyl acetate, carbonate, hydroxide, phosphate, and cysteine were measured. The pre-edge peak was observed for U(VI) compounds which is affected by the FWHM of the white line peak. It was suggested that uranyl carbonate has the highest symmetry of the uranyl compounds studied. Differences between the shoulder peak of carbonate and that of acetate in the experimental data were supported by those in the FDMNES. This finding suggests that HERFD-XANES can distinguish coordination structure of U with similar ligands in contrast to conventional XANES. This approach would pave the way for future studies on the analysis of the ligand exchange as well as the reduction of U in biological fluids, thereby improving the assessment of U decorporation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAkihiro Uehara: conceptualization, methodology, formal analysis, investigation, writing \u0026ndash; original draft, visualization. Daiju Matsumura: methodology, investigation. writing \u0026ndash; review and editing.Daisuke Akiyama: investigation, methodologyAkira Kirishima, investigation, writing \u0026ndash; review and editing.Shino Homma-Takeda: writing \u0026ndash;review and editing, funding acquisition.Teruaki Konishi: writing \u0026ndash;review and editing, project administration.Takumi Yomogida, methodology, investigation, formal analysis.Kenji Ishii: methodology, investigation, resources, writing \u0026ndash; review and editing, supervision.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe thank Dr. Takuya Tsuji (Materials Sciences Research Center, Japan Atomic Energy Agency) and Dr. Ayumi Shiro (Synchrotron Radiation Research Center, QST) for technical supports of XAFS measurements at BL14B1 line. We also thank Mr. Yoshinari Shiino and Mr. Kohei Iwaya (Department of Safety Administration, QST) for their assistance of the experimental procedure including the nuclear fuel materials. A.U. thanks Prof. Hisashi Hayashi (Japan Women's University) for useful suggestions and constructive comments on the manuscript. X-ray absorption measurements were performed at the beamline BL11XU and BL14B1, SPring-8, Japan, based on the proposal Nos. 2023B3557, 2024A3557, 2024B3557 for BL11XU and Nos. 2022A3662, 2022B3662, 2023A3662, 2023B3662, 2024A3662, 2024B3662, 2025A3662 for BL14B1, respectively. This work was performed under the Cooperative Research Program of \u0026ldquo;Network Joint Research Center for Materials and Devices (MEXT).\u0026rdquo; This work was supported by JSPS KAKENHI Grant Numbers 19H05775 and 20K05391.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDenecke MA (2024) Synchrotron investigations in environmental radiochemistry research. J Radioanal Nucl Ch\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUehara A, Matsumura D, Tsuji T, Yakumaru H, Tanaka I, Shiro A, Saitoh H, Ishihara H (2022) Homma-Takeda, Uranium chelating ability of decorporation agents in serum evaluated by X-ray absorption spectroscopy. Anal Methods 14:2439\u0026ndash;2445\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKowalska JK, Lima FA, Pollock CJ, Rees JA, DeBeer S (2016) A Practical Guide to High-resolution X-ray Spectroscopic Measurements and their Applications in Bioinorganic Chemistry. Isr J Chem 56:803\u0026ndash;815\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eProux O, Lahera E, Net WD, Kieffer I, Rovezzi M, Testemale D, Irar M, Thomas S, Aguilar-Tapia A, Bazarkina EF, Prat A, Tella M, Auffan M, Rose J, Hazemann JL (2017) High-Energy Resolution Fluorescence Detected X-Ray Absorption Spectroscopy: A Powerful New Structural Tool in Environmental Biogeochemistry Sciences. J Environ Qual 46:1146\u0026ndash;1157\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBuzanich AG (2022) Recent developments of X-ray absorption spectroscopy as analytical tool for biological and biomedical applications. X-Ray Spectrom 51:294\u0026ndash;303\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThomas SA, Mishra B, Myneni SCB (2019) High Energy Resolution-X-ray Absorption Near Edge Structure Spectroscopy Reveals Zn Ligation in Whole Cell Bacteria. J Phys Chem Lett 10:2585\u0026ndash;2592\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKvashnina KO, Butorin SM (2022) High-energy resolution X-ray spectroscopy at actinide M4,5 and ligand K edges: what we know, what we want to know, and what we can know. Chem Commun 58:327\u0026ndash;342\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCaciuffo R, Lander GH, van der Laan G (2023) Synchrotron radiation techniques and their application to actinide materials. Rev Mod Phys, 95\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVitova T, Kvashnina KO, Nocton G, Sukharina G, Denecke MA, Butorin SM, Mazzanti M, Caciuffo R, Soldatov A, Behrends T, Geckeis H (2010) High energy resolution x-ray absorption spectroscopy study of uranium in varying valence states. Phys Rev B, 82\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVitova T, Green JC, Denning RG, L\u0026ouml;ble M, Kvashnina K, Kas JJ, Jorissen K, Rehr JJ, Malcherek T, Denecke MA (2015) Polarization Dependent High Energy Resolution X-ray Absorption Study of Dicesium Uranyl Tetrachloride. Inorg Chem 54:174\u0026ndash;182\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLLorens I, Solari PL, Sitaud B, Bes R, Cammelli S, Hermange H, Othmane G, Safi S, Moisy P, Wahu S, Bresson C, Schlegel ML, Menut D, Bechade JL, Martin P, Hazemann JL, Proux O (2014) Den Auwer, X-ray absorption spectroscopy investigations on radioactive matter using MARS beamline at SOLEIL synchrotron. Radiochim Acta 102:957\u0026ndash;972\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBes R, Rivenet M, Solari PL, Kvashnina KO, Scheinost AC, Martin PM (2016) Use of HERFD-XANES at the U L3- and M4-Edges To Determine the Uranium Valence State on [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3]. Inorg Chem 55:4260\u0026ndash;4270\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDewey C, Sokaras D, Kroll T, Bargar JR, Fendorf S (2020) Calcium-Uranyl-Carbonato Species Kinetically Limit U(VI) Reduction by Fe(II) and Lead to U(V)-Bearing Ferrihydrite. Environ Sci Technol 54:6021\u0026ndash;6030\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKawamura N, Hirose Y, Honda F, Shimokasa R, Ishimatsu N, Mizumaki M, Kawaguchi SI, Hirao N, Mimura K (2020) Study on the Correlation of U Valence States with U\u0026ndash;U Distance in UPd2Cd20, in: Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLeinders G, Bes R, Kvashnina KO, Verwerft M (2020) Local Structure in U(IV) and U(V) Environments: The Case of U3O7. Inorg Chem 59:4576\u0026ndash;4587\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHunault MOJY, Menut D, Tougait O (2021) Alkali Uranyl Borates: Bond Length, Equatorial Coordination and 5f States, vol 11. Crystals\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBes R, Leinders G, Kvashnina K (2022) Application of multi-edge HERFD-XAS to assess the uranium valence electronic structure in potassium uranate (KUO3). J Synchrotron Radiat 29:21\u0026ndash;29\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYomogida T, Akiyama D, Ouchi K, Kumagai Y, Higashi K, Kitatsuji Y, Kirishima A, Kawamura N, Takahashi Y (2022) Application of High-Energy-Resolution X-ray Absorption Spectroscopy at the U L3-Edge to Assess the U(V) Electronic Structure in FeUO4. Inorg Chem 61:20206\u0026ndash;20210\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eK\u0026ouml;hler L, Patzschke M, Bauters S, Vitova T, Butorin SM, Kvashnina KO, Schmidt M, Stumpf T, M\u0026auml;rz J (2022) Insights into the Electronic Structure of a U(IV) Amido and U(V) Imido Complex. Chem-Eur J, 28\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVettese GF, Morris K, Natrajan LS, Shaw S, Vitova T, Galanzew J, Jones DL, Lloyd JR (2020) Multiple Lines of Evidence Identify U(V) as a Key Intermediate during U(VI) Reduction by Shewanella oneidensis MR1. Environ Sci Technol 54:2268\u0026ndash;2276\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMolinas M, Faizova R, Brown A, Galanzew J, Schacherl B, Bartova B, Meibom KL, Vitova T, Mazzanti M (2021) Bernier-Latmani, Biological Reduction of a U(V)-Organic Ligand Complex. Environ Sci Technol 55:4753\u0026ndash;4761\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHilpmann S, Rossberg A, Steudtner R, Drobot B, Hubner R, Bok F, Prieur D, Bauters S, Kvashnina KO, Stumpf T, Cherkouk A (2023) Presence of uranium(V) during uranium(VI) reduction by Desulfosporosinus hippei DSM 8344(T). Sci Total Environ 875:162593\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eG\u0026uuml;nther A, Geipel G, Bernhard G (2007) Complex formation of uranium(VI) with the amino acids l-glycine and l-cysteine: A fluorescence emission and UV\u0026ndash;Vis absorption study. Polyhedron 26:59\u0026ndash;65\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKirishima A, Takei M, Uehara A, Akiyama D (2025) Determination of the thermodynamic quantities for complex formation of U(VI) with amino acids in aqueous solution. J Chem Thermodyn, 206\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUehara A, Akiyama D, Ikeda-Ohno A, Numako C, Terada Y, Nitta K, Ina T, Homma-Takeda S, Kirishima A, Sato N (2022) Speciation on the reaction of uranium and zirconium oxides treated under oxidizing and reducing atmospheres. J Nucl Mater 559:153422\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKirkegaard MC, Spano TL, Ambrogio MW, Niedziela JL, Miskowiec A, Shields AE, Anderson BB (2019) Formation of a uranyl hydroxide hydrate hydration of [(UOF)(HO)]\u0026bull;4HO. Dalton Trans 48:13685\u0026ndash;13698\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGurzhiy VV, Kalashnikova SA, Kuporev IV, Plasil J (2021) Crystal Chemistry and Structural Complexity of the Uranyl Carbonate Minerals and Synthetic Compounds, Crystals, 11\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFoster RI, Kim KW, Lee KY (2020) Uranyl phosphate (MUOPO) precipitation for uranium sequestering: formation and physicochemical characterisation. J Radioanal Nucl Ch 324:1265\u0026ndash;1273\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRavel B, Newville M, ARTEMIS ATHENA (2005) HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. J Synchrotron Radiat 12:537\u0026ndash;541\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJoly Y (2001) X-ray absorption near-edge structure calculations beyond the muffin-tin approximation. Phys Rev B, 63\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Uranium, HERFD- XANES, bio-ligands, acetate, carbonate, cysteine, FDMNES","lastPublishedDoi":"10.21203/rs.3.rs-7673847/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7673847/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003eABSRACT\u003c/b\u003e\u003c/p\u003e\u003cp\u003eUranium has the potential to form complexes with biological ligands in body fluids upon internal exposure. The coordination of U with biological ligands was analyzed by using high energy resolution fluorescence detected X-ray absorption near edge fine structure (HERFD-XANES) at U L\u003csub\u003e3\u003c/sub\u003e edge. A spectra of uranyl compounds such as uranium dioxide, uranyl acetate, carbonate, phosphate, hydroxide, and cysteine were measured by HERFD-XANES spectroscopy. Symmetry of the compounds was discussed on the results of linear combination least-squares fit modeling of the spectra. Pre-edge peak of U(VI) samples in HERFD-XANES spectra were different from those obtained with conventional XANES spectra. It was suggested that uranyl carbonate has the highest symmetry of the uranyl compounds studied. Differences between the shoulder peak of carbonate and that of acetate in the HERFD-XANES were observed, and peak energies in the experimental data were supported by those in the calculated data based on the finite difference method for near-edge structure. This finding suggests that HERFD-XANES can successfully distinguish coordination structure with similar ligands in contrast to conventional XANES.\u003c/p\u003e","manuscriptTitle":"Fundamental Study on Uranyl Coordination With Biological Ligands Analyzed by Herfd-xanes Spectroscopy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-09 20:59:38","doi":"10.21203/rs.3.rs-7673847/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8f8e477f-a528-4b78-9543-951ff51a1448","owner":[],"postedDate":"October 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-02T16:15:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-09 20:59:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7673847","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7673847","identity":"rs-7673847","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}