| 1. |
- Nygren, Ulrika, et al.
(författare)
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Age determination of plutonium using inductively coupled plasma mass spectrometry
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 272:1, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- The age of plutonium is defined as the time since the last separation of the plutonium isotopes from their daughter nuclides. In this paper, a method for age determination based on analysis of 241Pu/241Am and 240Pu/236Pu using ICP-SFMS is described. Separation of Pu and Am was performed using a solid phase extraction procedure including UTEVA, TEVA, TRU and Ln-resins. The procedure provided separation factors adequate for this purpose. Age determinations were performed on two plutonium reference solutions from the Institute for Reference Materials and Measurements, IRMM081 (239Pu) and IRMM083 (240Pu), on sediment from the Marshall Islands (reference material IAEA367) and on soil from the Trinity test site (Trinitite). The measured ages based on the 241Am/241Pu ratio corresponded well with the time since the last parent-daughter separations of all the materials. The ages derived from the 236U/240Pu ratio were in agreement for the IRMM materials, but for IAEA367 the determination of 236U was interfered by tailing from 238U, and for Trinitite the determined age was biased due to formation of 236U in the detonation of the "Gadget".
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| 2. |
- Nygren, Ulrika, et al.
(författare)
-
Lanthanide phosphate interferences in actinide determination using inductively coupled plasma mass spectrometry
- 2005
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Ingår i: Journal of Analytical Atomic Spectrometry. - 0267-9477 .- 1364-5544. ; 20:6, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- The determination of actinides at low levels using ICP-MS can be interfered by polyatomic ions appearing at the same nominal mass-to-charge ratio. In this work, interferences initially found when analysing plutonium in soil and sediment samples were identified as lanthanide phosphates and the formation of these species examined. It was found that high sample gas flow rates and low rf powers enhanced the formation of lanthanide phosphates. All lanthanides studied (La, Ce, Pr and Nd) formed phosphates, albeit to various extents and of slightly different compositions. Furthermore, the lanthanide phosphate formation was verified by introducing the source of phosphorus, hydroxyethylidene diphosphonic acid (HEDPA), in an [1][8]O enriched water solution. This experiment also revealed that the HEDPA is essentially completely dissociated in the plasma and that the interfering species are most likely formed during ion extraction.
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