Bart Verlinden, Karen Van Hecke, Andreas Wilden, Giuseppe Modolo, Koen Binnemans, Thomas Cardinaels, Piotr M. Kowalski
Abstract Understanding the degradation mechanisms of organic compounds in an extreme radiolysis induced environment is important for designing efficient organic extractants for the separation of radionuclides from used nuclear fuel. In this paper, we present an in-depth computational chemistry-based molecular level analysis of the radiolytic degradation of diglycolamides, with a focus on structural and thermodynamic aspects of the process. The most vulnerable parts of the organic ligands prone to attack and degradation by radicals are identified via electronic density and bond strength analysis. We identified the C–O of the ether group as the weakest bond, which is further weakened by methylation. A plausible degradation path resulting from breaking the C–O bond by H radical attack is obtained by computation of free energy of the process. To investigate realistic reaction conditions, we accounted for the impact of solvation effects on the thermodynamic quantities, including solvation entropy effects. The resulting degradation mechanism is consistent with experimentally observed degradation products.
{"title":"First-principles study of the radiolytic degradation of diglycolamides","authors":"Bart Verlinden, Karen Van Hecke, Andreas Wilden, Giuseppe Modolo, Koen Binnemans, Thomas Cardinaels, Piotr M. Kowalski","doi":"10.1515/ract-2023-0176","DOIUrl":"https://doi.org/10.1515/ract-2023-0176","url":null,"abstract":"Abstract Understanding the degradation mechanisms of organic compounds in an extreme radiolysis induced environment is important for designing efficient organic extractants for the separation of radionuclides from used nuclear fuel. In this paper, we present an in-depth computational chemistry-based molecular level analysis of the radiolytic degradation of diglycolamides, with a focus on structural and thermodynamic aspects of the process. The most vulnerable parts of the organic ligands prone to attack and degradation by radicals are identified via electronic density and bond strength analysis. We identified the C–O of the ether group as the weakest bond, which is further weakened by methylation. A plausible degradation path resulting from breaking the C–O bond by H radical attack is obtained by computation of free energy of the process. To investigate realistic reaction conditions, we accounted for the impact of solvation effects on the thermodynamic quantities, including solvation entropy effects. The resulting degradation mechanism is consistent with experimentally observed degradation products.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134990881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The treatment of Hanford tank waste is one of the most technically challenging environmental cleanup activities for the U.S. Department of Energy to date. To expedite the processing of liquid waste stored in underground tanks in southeastern Washington state, it is necessary to remove the significant dose contributor, 137Cs. Toward this effort, ion exchange with crystalline silicotitanate (CST) has been employed as part of the Tank Side Cesium Removal system. The model used to predict Cs exchange onto CST was developed using activity coefficients calculated from the Bromley equation. A series of batch contact tests that varied in [Na] were conducted to look at the impact of Na concentration on Cs distribution. Experimental distribution ratios (K d) were compared to the distribution ratios predicted using three different activity coefficient models: (1) commercially available HSC software, (2) the Bromley equation, and (3) a simplified approach adapted from Marcos-Arroyo et al. Ultimately, the Bromley method underpredicted the effect of ionic strength on the Na activity coefficient (γ Na+), HSC overestimated the impact of ionic strength on the expected performance due to the Cs activity coefficient (γ Cs+), but the simplified approach predicted the experimental K d values quite well in a binary matrix. Expansion of this approach in complex matrices is necessary for application to Hanford tank waste.
{"title":"Investigation into Na and Cs activity coefficients in high salt solutions to support Cs removal in Hanford tank waste","authors":"E. Campbell, A. Westesen, R. Peterson","doi":"10.1515/ract-2023-0134","DOIUrl":"https://doi.org/10.1515/ract-2023-0134","url":null,"abstract":"Abstract The treatment of Hanford tank waste is one of the most technically challenging environmental cleanup activities for the U.S. Department of Energy to date. To expedite the processing of liquid waste stored in underground tanks in southeastern Washington state, it is necessary to remove the significant dose contributor, 137Cs. Toward this effort, ion exchange with crystalline silicotitanate (CST) has been employed as part of the Tank Side Cesium Removal system. The model used to predict Cs exchange onto CST was developed using activity coefficients calculated from the Bromley equation. A series of batch contact tests that varied in [Na] were conducted to look at the impact of Na concentration on Cs distribution. Experimental distribution ratios (K d) were compared to the distribution ratios predicted using three different activity coefficient models: (1) commercially available HSC software, (2) the Bromley equation, and (3) a simplified approach adapted from Marcos-Arroyo et al. Ultimately, the Bromley method underpredicted the effect of ionic strength on the Na activity coefficient (γ Na+), HSC overestimated the impact of ionic strength on the expected performance due to the Cs activity coefficient (γ Cs+), but the simplified approach predicted the experimental K d values quite well in a binary matrix. Expansion of this approach in complex matrices is necessary for application to Hanford tank waste.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46599146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Graphene oxide (GO) and zinc oxide (ZnO) were synthesized via the Tour’ and sol-gel methods, respectively. Adsorption potentials of Th(IV) ions were investigated with the functionalization of GO with ZnO nanoparticles (GO-ZnO) and compared with the GO. Studies concerning factors affecting the adsorption process, kinetics, adsorption isotherms, and thermodynamic properties were carried out. In this study, the optimum pH for the adsorption of Th(IV) ions is 3.0, and quickly reaching equilibrium is an indication of the high efficacy of the sorbent. A pseudo-second order adsorption model fits the kinetic data well. Experimental results were compared with Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. These results show that the Langmuir model fits the data well. Measured thermodynamic parameters, Gibbs free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) indicate that the adsorption of Th(IV) on GO−ZnO is spontaneous and endothermic in nature. According to the linear fit in the Langmuir isotherm model, the maximum adsorption capacity of GO and GO-ZnO at 298 K occurs at 109.89 mg/g and 243.90 mg/g, respectively. The results show that decoration with ZnO nanoparticles is a good method to improve the adsorption capacity of GO for Th(IV) removal.
{"title":"Adsorption of Th(IV) ions from aqueous solutions by ZnO functionalized graphene oxide","authors":"İ. G. Kaptanoğlu, S. Yusan","doi":"10.1515/ract-2023-0160","DOIUrl":"https://doi.org/10.1515/ract-2023-0160","url":null,"abstract":"Abstract Graphene oxide (GO) and zinc oxide (ZnO) were synthesized via the Tour’ and sol-gel methods, respectively. Adsorption potentials of Th(IV) ions were investigated with the functionalization of GO with ZnO nanoparticles (GO-ZnO) and compared with the GO. Studies concerning factors affecting the adsorption process, kinetics, adsorption isotherms, and thermodynamic properties were carried out. In this study, the optimum pH for the adsorption of Th(IV) ions is 3.0, and quickly reaching equilibrium is an indication of the high efficacy of the sorbent. A pseudo-second order adsorption model fits the kinetic data well. Experimental results were compared with Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. These results show that the Langmuir model fits the data well. Measured thermodynamic parameters, Gibbs free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) indicate that the adsorption of Th(IV) on GO−ZnO is spontaneous and endothermic in nature. According to the linear fit in the Langmuir isotherm model, the maximum adsorption capacity of GO and GO-ZnO at 298 K occurs at 109.89 mg/g and 243.90 mg/g, respectively. The results show that decoration with ZnO nanoparticles is a good method to improve the adsorption capacity of GO for Th(IV) removal.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49213307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The cross-section, a measure of the probability that a nuclear reaction will occur, needs to be calculated properly. The level density model used in the computations is one of several factors which may affect the theoretical value of the cross-section in a nuclear reaction. In this study, it is aimed to investigate the influence of level density models on the cross-section calculations in the production of some strontium isotopes from the natural abundance of rubidium by proton induced reactions. To this end, calculations have been made by triggering the six level density models that can be used in the TALYS code, one after the other. To allow a visual comparison of the effects of the level density models, the obtained calculation outputs and the experimental results from the literature have been plotted together. Furthermore, numerical comparisons have been made with the calculated values of a deviation factor.
{"title":"Production cross-section calculations of some strontium isotopes via (p,x) reactions on natural abundance rubidium using different level density models","authors":"M. Şekerci, H. Özdoğan, A. Kaplan","doi":"10.1515/ract-2023-0149","DOIUrl":"https://doi.org/10.1515/ract-2023-0149","url":null,"abstract":"Abstract The cross-section, a measure of the probability that a nuclear reaction will occur, needs to be calculated properly. The level density model used in the computations is one of several factors which may affect the theoretical value of the cross-section in a nuclear reaction. In this study, it is aimed to investigate the influence of level density models on the cross-section calculations in the production of some strontium isotopes from the natural abundance of rubidium by proton induced reactions. To this end, calculations have been made by triggering the six level density models that can be used in the TALYS code, one after the other. To allow a visual comparison of the effects of the level density models, the obtained calculation outputs and the experimental results from the literature have been plotted together. Furthermore, numerical comparisons have been made with the calculated values of a deviation factor.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42119904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Philipp Droop, Shaohuang Chen, Melissa J. Radford, E. Paulssen, B. Gates, R. Reilly, V. Radchenko, C. Hoehr
Abstract Meitner-Auger-electron emitters have a promising potential for targeted radionuclide therapy of cancer because of their short range and the high linear energy transfer of Meitner-Auger-electrons (MAE). One promising MAE candidate is 197m/gHg with its half-life of 23.8 h and 64.1 h, respectively, and high MAE yield. Gold nanoparticles (AuNPs) that are labelled with 197m/gHg could be a helpful tool for radiation treatment of glioblastoma multiforme when infused into the surgical cavity after resection to prevent recurrence. To produce such AuNPs, 197m/gHg was embedded into pristine AuNPs. Two different syntheses were tested starting from irradiated gold containing trace amounts of 197m/gHg. When sodium citrate was used as reducing agent, no 197m/gHg labelled AuNPs were formed, but with tannic acid, 197m/gHg labeled AuNPs were produced. The method was optimized by neutralizing the pH (pH = 7) of the Au/197m/gHg solution, which led to labelled AuNPs with a size of 12.3 ± 2.0 nm as measured by transmission electron microscopy. The labelled AuNPs had a concentration of 50 μg (gold)/mL with an activity of 151 ± 93 kBq/mL (197gHg, time corrected to the end of bombardment).
{"title":"Synthesis of 197m/gHg labelled gold nanoparticles for targeted radionuclide therapy","authors":"Philipp Droop, Shaohuang Chen, Melissa J. Radford, E. Paulssen, B. Gates, R. Reilly, V. Radchenko, C. Hoehr","doi":"10.1515/ract-2023-0144","DOIUrl":"https://doi.org/10.1515/ract-2023-0144","url":null,"abstract":"Abstract Meitner-Auger-electron emitters have a promising potential for targeted radionuclide therapy of cancer because of their short range and the high linear energy transfer of Meitner-Auger-electrons (MAE). One promising MAE candidate is 197m/gHg with its half-life of 23.8 h and 64.1 h, respectively, and high MAE yield. Gold nanoparticles (AuNPs) that are labelled with 197m/gHg could be a helpful tool for radiation treatment of glioblastoma multiforme when infused into the surgical cavity after resection to prevent recurrence. To produce such AuNPs, 197m/gHg was embedded into pristine AuNPs. Two different syntheses were tested starting from irradiated gold containing trace amounts of 197m/gHg. When sodium citrate was used as reducing agent, no 197m/gHg labelled AuNPs were formed, but with tannic acid, 197m/gHg labeled AuNPs were produced. The method was optimized by neutralizing the pH (pH = 7) of the Au/197m/gHg solution, which led to labelled AuNPs with a size of 12.3 ± 2.0 nm as measured by transmission electron microscopy. The labelled AuNPs had a concentration of 50 μg (gold)/mL with an activity of 151 ± 93 kBq/mL (197gHg, time corrected to the end of bombardment).","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49277165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maja Chochevska, Marija Atanasova Lazareva, Katerina Kolevska, Maja Velichkovska, J. Koziorowski, E. Ivanovska, B. Angelovska, A. Ugrinska
Abstract [18F]Fluoromisonidazole ([18F]FMISO) as nitroimidazole derivative with 18F radioisotope is a widely known and studied hypoxia marker for PET imaging. A number of automated synthesis modules and purification strategies for production of [18F]FMISO have been described in recent years. The goal of this work was to develop [18F]FMISO synthesis process with Synthera module with solid phase extraction (SPE) Sep-Pak purification cartridges. To adjust the reaction conditions we synthesized [18F]FMISO under different reaction conditions and using various reversed-phase (RP) purification cartridges (HLB light, HLB plus, tC18, C18 environmental, Chromafix PS-RP). The synthesis was performed by nucleophilic substitution of commercial 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonylpropanediol precursor and subsequent acidic hydrolysis. Further, the product mixture was purified by passing through the SPE cartridge. The produced [18F]FMISO was retained on the cartridge, while the impurities passed through the cartridge into a waste. The retained [18F]FMISO was then eluted with small amounts of ethanol in water and eluates were collected in the final product vial. The product sample was subjected to quality control tests, while for waste sample chemical and radiochemical tests were performed. We have developed an efficient synthesis method of [18F]FMISO with cartridge purification with good radiochemical yield (RCY) and high chemical and radiochemical purity in accordance with the Ph. Eur. Monograph for Fluoromisonidazole (18F) injection.
{"title":"[18F]Fluoromisonidazole synthesis method: development and optimization by cartridge purification","authors":"Maja Chochevska, Marija Atanasova Lazareva, Katerina Kolevska, Maja Velichkovska, J. Koziorowski, E. Ivanovska, B. Angelovska, A. Ugrinska","doi":"10.1515/ract-2023-0169","DOIUrl":"https://doi.org/10.1515/ract-2023-0169","url":null,"abstract":"Abstract [18F]Fluoromisonidazole ([18F]FMISO) as nitroimidazole derivative with 18F radioisotope is a widely known and studied hypoxia marker for PET imaging. A number of automated synthesis modules and purification strategies for production of [18F]FMISO have been described in recent years. The goal of this work was to develop [18F]FMISO synthesis process with Synthera module with solid phase extraction (SPE) Sep-Pak purification cartridges. To adjust the reaction conditions we synthesized [18F]FMISO under different reaction conditions and using various reversed-phase (RP) purification cartridges (HLB light, HLB plus, tC18, C18 environmental, Chromafix PS-RP). The synthesis was performed by nucleophilic substitution of commercial 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonylpropanediol precursor and subsequent acidic hydrolysis. Further, the product mixture was purified by passing through the SPE cartridge. The produced [18F]FMISO was retained on the cartridge, while the impurities passed through the cartridge into a waste. The retained [18F]FMISO was then eluted with small amounts of ethanol in water and eluates were collected in the final product vial. The product sample was subjected to quality control tests, while for waste sample chemical and radiochemical tests were performed. We have developed an efficient synthesis method of [18F]FMISO with cartridge purification with good radiochemical yield (RCY) and high chemical and radiochemical purity in accordance with the Ph. Eur. Monograph for Fluoromisonidazole (18F) injection.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44833353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Shuza Uddin, M. Mezbah Uddin, R. Khan, M. Mehedi Hasan, M. Asad Shariff, M. Obaidur Rahman, S. Qaim
Abstract Integral cross sections of the reactions 84Sr(n,p)84Rb, 86Sr(n,p)86Rb and 87Sr(n,n′)87mSr, over the fast neutron spectrum of a TRIGA reactor above 0.5 MeV, were measured for the first time. The results were used for integral tests of the evaluated excitation functions in the data libraries, ENDF/B-VIII.0, ROSFOND-2010, JEFF-3.3, JENDL-5 and TENDL-2021. The integral measurements are generally consistent with the integrated values within 12 %, except for a few cases. The two data libraries ENDF/B-VIII.0 and ROSFOND-2010 appear to need some improvement with regard to the reactions investigated in this work.
{"title":"Measurement of spectrum-averaged cross sections of the (n,p) and (n,n′) reactions on strontium by fast neutrons of a TRIGA reactor: comparison with integrated data from excitation functions of various data libraries","authors":"M. Shuza Uddin, M. Mezbah Uddin, R. Khan, M. Mehedi Hasan, M. Asad Shariff, M. Obaidur Rahman, S. Qaim","doi":"10.1515/ract-2023-0155","DOIUrl":"https://doi.org/10.1515/ract-2023-0155","url":null,"abstract":"Abstract Integral cross sections of the reactions 84Sr(n,p)84Rb, 86Sr(n,p)86Rb and 87Sr(n,n′)87mSr, over the fast neutron spectrum of a TRIGA reactor above 0.5 MeV, were measured for the first time. The results were used for integral tests of the evaluated excitation functions in the data libraries, ENDF/B-VIII.0, ROSFOND-2010, JEFF-3.3, JENDL-5 and TENDL-2021. The integral measurements are generally consistent with the integrated values within 12 %, except for a few cases. The two data libraries ENDF/B-VIII.0 and ROSFOND-2010 appear to need some improvement with regard to the reactions investigated in this work.","PeriodicalId":21167,"journal":{"name":"Radiochimica Acta","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44581344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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