The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Manuel Miró - One of the best experts on this subject based on the ideXlab platform.
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high throughput sequential injection method for simultaneous determination of plutonium and Neptunium in environmental solids using macroporous anion exchange chromatography followed by inductively coupled plasma mass spectrometric detection
Analytical Chemistry, 2011Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and Neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with Neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and Neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and Neptunium along the separation protocol. It is proven that plutonium-242 (242Pu) performs well as a tracer for monitoring the chemical yield of Neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and pr...
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Rapid and simultaneous determination of Neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and Neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI) system for the isolation of plutonium and Neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and Neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct procedures were investigated and compared for the adjustment of oxidation states of plutonium and Neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both plutonium and Neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and Neptunium as demanded in emergency actions.
Jixin Qiao - One of the best experts on this subject based on the ideXlab platform.
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high throughput sequential injection method for simultaneous determination of plutonium and Neptunium in environmental solids using macroporous anion exchange chromatography followed by inductively coupled plasma mass spectrometric detection
Analytical Chemistry, 2011Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and Neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with Neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and Neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and Neptunium along the separation protocol. It is proven that plutonium-242 (242Pu) performs well as a tracer for monitoring the chemical yield of Neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and pr...
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Rapid and simultaneous determination of Neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and Neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI) system for the isolation of plutonium and Neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and Neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct procedures were investigated and compared for the adjustment of oxidation states of plutonium and Neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both plutonium and Neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and Neptunium as demanded in emergency actions.
Ines R. Triay - One of the best experts on this subject based on the ideXlab platform.
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a reactive transport model of Neptunium migration from the potential repository at yucca mountain
Journal of Hydrology, 1998Co-Authors: Hari S Viswanathan, B.a. Robinson, Albert J Valocchi, Ines R. TriayAbstract:Abstract Characterization and performance assessment studies for the potential high-level nuclear waste repository at Yucca Mountain have identified 2 3 7 Np as a radionuclide of concern for the proposed repository. To predict the migration of Neptunium after a repository breach, an understanding of the relevant hydrologic and geochemical processes is required. The hydrologic flow in the unsaturated zone at Yucca Mountain is dependent on the infiltration rate, the stratigraphy of the vadose zone, and the heat generated by the decaying radioactive waste. The geochemical processes that strongly affect 2 3 7 Np migration include: solubility-limited release of 2 3 7 Np from the near-field environment, aqueous speciation of Neptunium into non-sorbing carbonate/hydroxy complexes and the sorbing NpO 2 + cation, sorption of Neptunium onto the zeolitic tuffs via an ion exchange mechanism, and radioactive decay. The finite element heat and mass transfer (FEHM) code was used to investigate the coupled effects of chemical interactions and heat on Neptunium transport from the potential repository to the water table. The selective coupling method is introduced to solve these reactive transport problems. The simulations indicate that in the absence of irreversible changes in the hydrologic and transport properties, the heat pulse does not significantly affect the migration of Neptunium, as the time scale of heat pulse propagation is shorter than the time scales associated with Neptunium release and migration. Water chemistry, particularly pH, calcium, and sodium concentration significantly affect the retardation of Neptunium by the zeolitic rocks between the repository and the water table.
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Neptunium retardation with tuffs and groundwaters from Yucca Mountain
High Level Radioactive Waste Management, 1993Co-Authors: Ines R. Triay, B.a. Robinson, R.m. Lopez, A.j. Mitchell, C.m. OverlyAbstract:The retardation of Neptunium was studied using batch sorption and column techniques. Pure mineral separates, tuffs and groundwaters from Yucca Mountain were used for these experiments. Our results indicate that Np sorption increases rapidly as the pH of the water increases in cases where surface complexation is thought w be the dominant sorption mechanism. Oxide minerals (such as hematite) sorb Np strongly; therefore, these minerals even at trace levels in Yucca Mountain tuffs can result in significant Np retardation. Neptunium in groundwaters from Yucca Mountain exhibited a significant amount of sorption onto quartz. Neptunium sorption onto quartz is important because of the large quantity of silica in the tuffs. Elution of Neptunium solutions in groundwater through columns made of crushed tuff yielded sorption coefficients that agree with the sorption results obtained using batch sorption techniques. Agreement between batch and column experiments indicates a Neptunium sorption mechanism that is linear, reversible, and instantaneous.
Xiaolin Hou - One of the best experts on this subject based on the ideXlab platform.
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high throughput sequential injection method for simultaneous determination of plutonium and Neptunium in environmental solids using macroporous anion exchange chromatography followed by inductively coupled plasma mass spectrometric detection
Analytical Chemistry, 2011Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and Neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with Neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and Neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and Neptunium along the separation protocol. It is proven that plutonium-242 (242Pu) performs well as a tracer for monitoring the chemical yield of Neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and pr...
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Rapid and simultaneous determination of Neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and Neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI) system for the isolation of plutonium and Neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and Neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct procedures were investigated and compared for the adjustment of oxidation states of plutonium and Neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both plutonium and Neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and Neptunium as demanded in emergency actions.
Per Roos - One of the best experts on this subject based on the ideXlab platform.
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high throughput sequential injection method for simultaneous determination of plutonium and Neptunium in environmental solids using macroporous anion exchange chromatography followed by inductively coupled plasma mass spectrometric detection
Analytical Chemistry, 2011Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and Neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with Neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and Neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and Neptunium along the separation protocol. It is proven that plutonium-242 (242Pu) performs well as a tracer for monitoring the chemical yield of Neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and pr...
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Rapid and simultaneous determination of Neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS
Journal of Analytical Atomic Spectrometry, 2010Co-Authors: Jixin Qiao, Xiaolin Hou, Per Roos, Manuel MiróAbstract:This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and Neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI) system for the isolation of plutonium and Neptunium from matrix elements and interfering nuclides. Valence adjustment is a crucial step to ensure the same chemical behavior of plutonium and Neptunium onto the TEVA column and consequently to accomplish their simultaneous separation and detection. Distinct procedures were investigated and compared for the adjustment of oxidation states of plutonium and Neptunium to Pu(IV) and Np(IV), respectively. A two-step protocol using sulfite and concentrated nitric acid as redox reagents was proven to be the most effective method. The analytical results for both plutonium and Neptunium in three reference materials were in agreement with the recommended or literature values at the 0.05 significance level. The developed method is suitable for the analysis of up to 10 g of soil and 20 g of seaweed samples. The extraction chromatographic separation within the SI system for a single sample takes less than 1.5 h. As compared to batchwise procedures, the developed method significantly improves the analysis efficiency, reduces the labor intensity and expedites the simultaneous determination of plutonium and Neptunium as demanded in emergency actions.