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Qin N, Zheng J, Guosheng Yang, Tagami K. A comprehensive survey of reference materials for their use in quality assurance for the determination of Np-237 in environmental samples. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 271:107328. [PMID: 37951039 DOI: 10.1016/j.jenvrad.2023.107328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 11/13/2023]
Abstract
Neptunium-237 (237Np) is one of the most hazardous radionuclides of public concern due to its radiological toxicity, long half-life and high environmental mobility. Standard reference materials (SRMs) with well characterized 237Np activity concentrations are valuable for method development and validation of 237Np determination in environmental samples. In this study, a comprehensive literature survey of 237Np activity concentrations in 25 SRMs was carried out covering the various matrices of sediment, soil, seawater, atmospheric particles, and biota. After data screening, arithmetic mean of the activity concentrations of 237Np in literatures were calculated as statistical values (SVs). Then, accuracies of different instrument analyses and acid digestion methods were evaluated based on the SVs. Finally, by optimizing the sector field ICP-MS analytical method, 237Np activity concentration in JSAC-0471 soil SRM was measured. The application of SVs provides 237Np activity concentration information in more SRMs. Besides SRMs certified by technically validated procedures, SRMs with SVs and the measurement of JASC-0471 provide more options for suitable selection of SRMs for 237Np determination.
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Affiliation(s)
- Ning Qin
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan; University of Science and Technology Beijing, Beijing, 100083, China
| | - Jian Zheng
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan.
| | - Guosheng Yang
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan
| | - Keiko Tagami
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan
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Yang Y, Luo M, Wu Y, Yuan N, He J, Guo H, An Q. Comparison for the simultaneous determination of 237Np and Pu isotopes between TEVA and TK200 resin. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 270:107290. [PMID: 37660455 DOI: 10.1016/j.jenvrad.2023.107290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/05/2023]
Abstract
A reliable and stable method was developed to accurately analyze neptunium (237Np) and plutonium isotopes in environmental samples using 242Pu or 236Pu as a tracer. Key parameters, including the valence adjustment conditions and the stabilities of Pu and Np in the different resins, were investigated using TK200 and TEVA resin. It was found that Pu and Np could be efficiently extracted simultaneously using TK200 resin under the optimal loading conditions (6-12 M HNO3) with the addition of 0.01-0.12 M NaNO2 for valence adjustment. These isotopes were subsequently stripped out using a solution containing 0.1 M HCl, 0.05 M HF, and 0.01 M NH2OH·HCl. The separation efficiencies of Pu and Np were >93%, and the chemical yield ratio between Np and Pu was maintained steady at an average of 1.00 ± 0.03 (n > 50) under the optimal conditions. The analytical method was validated by analyzing environmental soil samples spiked with known amounts of 239Pu and 237Np standard solutions or certified reference materials. The measured values of 237Np, 239Pu, and 240Pu obtained by inductively coupled plasma tandem mass spectrometry were consistent with their International Atomic Energy Agency literature values within a 95% confidence interval. These results confirm the reliability and high analytical precision (<6%) of this developed method using Pu as a non-isotopic tracer for monitoring the chemical yield of 237Np. The developed method can also be used for environmental pollutant monitoring and for tracer studies of the 237Np and Pu isotopes.
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Affiliation(s)
- Yao Yang
- China Institute for Radiation Protection, Taiyuan, China
| | - Maoyi Luo
- China Institute for Radiation Protection, Taiyuan, China; Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China.
| | - Yang Wu
- China Institute for Radiation Protection, Taiyuan, China; Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Ni Yuan
- China Institute for Radiation Protection, Taiyuan, China; Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Jingjing He
- China Institute for Radiation Protection, Taiyuan, China
| | - Hongmei Guo
- China Institute for Radiation Protection, Taiyuan, China
| | - Quan An
- China Institute for Radiation Protection, Taiyuan, China; Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
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Benedik L, Pilar AM, Prosen H, Jaćimović R, Povinec PP. Determination of ultra-trace levels of uranium and thorium in electrolytic copper using radiochemical neutron activation analysis. Appl Radiat Isot 2021; 175:109801. [PMID: 34118588 DOI: 10.1016/j.apradiso.2021.109801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 04/22/2021] [Accepted: 05/31/2021] [Indexed: 11/15/2022]
Abstract
Uranium and thorium as natural radioactive elements are present everywhere in the environment. Their trace levels are also present in various materials, such as copper, used as a shielding material in gamma-ray spectrometry, usually located very close to the detector. Ultra-low levels of uranium and thorium in electrolytic copper were determined in this study using radiochemical neutron activation analysis (RNAA) via their induced nuclides U-239/Np-239 and Pa-233, respectively. After irradiation of copper together with uranium and thorium standards, various techniques were used for their separation from the matrix. To isolate of short-lived U-239, solvent extraction in a combination of tributyl phosphate (TBP) in toluene was used. To separate Np-239 and Pa-233, extraction chromatography using TEVA and TK-400 resins was applied. Special attention was paid to the estimation of radiochemical recovery, which was determined in each sample aliquot using U-235, Np-238 and Pa-231 tracers. For quantification of induced nuclides and tracers used in the experiment, gamma-ray spectrometry was used. Obtained results showed that electrolytic copper samples contained impurities of uranium and thorium in ultra-trace levels: up to 45 pg/g (550 nBq/g) for uranium and up to 80 pg/g (330 nBq/g) for thorium. The electrolytic copper also contained impurities of Ag, As, Au, Sb, Se and Zn as observed using the k0-INAA technique.
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Affiliation(s)
- L Benedik
- Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia.
| | - A M Pilar
- Faculty of Chemistry and Chemical Technology, Večna Pot 113, SI-1000, Ljubljana, Slovenia
| | - H Prosen
- Faculty of Chemistry and Chemical Technology, Večna Pot 113, SI-1000, Ljubljana, Slovenia
| | - R Jaćimović
- Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
| | - P P Povinec
- Faculty of Mathematics, Physics and Informatics, Comenius University, 84248, Bratislava, Slovakia
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Ko YG. Preparation and characterization of electrodeposited layers as alpha sources for alpha-particle spectrometry. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07398-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Abstract
Separation of neptunium by solvent extraction has been based on tributylphosphate (TBP) for decades, but TBP is not fully incinerable, which adds to the burden of long-lived radioactive waste. Alternatives to TBP for uranium and plutonium extraction, such as the N,N-diakylamides, previously have been explored in the hopes of transitioning to an extractant that is incinerable. Four N,N-diakylamides, N,N-dihexylhexanamide (DHHA), N,N-dihexyloctanamide (DHOA), N,N-di(2-ethylhexyl)butanamide (DEHBA), and N,N-di(2-ethylhexyl)-iso-butanamide (DEHiBA) were considered in this work for their potential to extract millimolar concentrations of Np(IV), Np(V), and Np(VI) from nitric acid solutions into organic solutions containing 1 M extractant in Exxsol D60. Under these conditions the branching of the alkyl substituents affects the extractability of Np(VI) and Np(IV), causing three of the dialkylamides, DHHA, DHOA and DEHBA, to extract neptunium in the expected order Np(VI) > Np(IV) > > Np(V). In contrast, branched DEHiBA is so poor an extractant for Np(IV) that the extraction order becomes Np(VI) > > Np(V) > Np(IV) between 0.1 and 5.6 M HNO3 due to partial oxidation of the Np(V) in nitric acid.
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Affiliation(s)
- Jarrod M. Gogolski
- Nuclear Science and Engineering Program, Colorado School of Mines , Golden, CO 80401 , USA
| | - Peter R. Zalupski
- Aqueous Separations and Radiochemistry, Idaho National Laboratory , Idaho Falls, ID 83415 , USA
| | - Travis S. Grimes
- Aqueous Separations and Radiochemistry, Idaho National Laboratory , Idaho Falls, ID 83415 , USA
| | - Mark P. Jensen
- Nuclear Science and Engineering Program, Colorado School of Mines , Golden, CO 80401 , USA
- Department of Chemistry, Colorado School of Mines , Golden, CO 80401 , USA
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Popov L. Determination of plutonium isotopes in environmental samples by extraction chromatography with triisooctylamine - polyethylene resin. Appl Radiat Isot 2019; 146:48-56. [PMID: 30753984 DOI: 10.1016/j.apradiso.2019.01.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 01/13/2019] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
Abstract
Method for determination of plutonium isotopes in various environmental samples is presented. The separation and purification of plutonium is attained by extraction chromatography with triisooctylamine - polyethylene resin in nitric and hydrochloric acid media. Plutonium is measured by alpha-particle spectrometry after electrodeposition on a stainless steel disk. The analytical quality was checked by analyzing reference materials with different matrices from IAEA (Soil-6, IAEA-375, IAEA-384, IAEA-414) and NPL (AL-2009, AL-2010, AL-2011, AL-2013, AB-2014). The major advantages of the method are the low cost of the analysis, high radiochemical yields and high decontamination factors from the matrix elements, natural and man-made radionuclides.
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Affiliation(s)
- L Popov
- Kozloduy Nuclear Power Plant, Safety Department, Radioecological Monitoring, 3321, Kozloduy, Bulgaria.
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Smodiš B, Benedik L, Jaćimović R. Analytical radiochemistry of neutron activated samples in practice. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-6275-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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