Estimation of the formation rates of polyatomic species of heavy metals in plutonium analyses using a multicollector ICP-MS with a desolvating nebulizer

Journal Article · Thu Jan 01 04:00:00 EST 2015 · Journal of Analytical Atomic Spectrometry

DOI:https://doi.org/10.1039/C4JA00282B· OSTI ID:1188890

Mitroshkov, Alexandre V. ^[1]; Olsen, Khris B. ^[1]; Thomas, Linda M. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

The analyses of IAEA and environmental samples for Plutonium isotopic content are conducted normally at very low concentrations of Pu–usually in the range of part per trillion level and even more often at the parts per quadrillion level. To analyze such low concentrations, the interferences in the analytical solution must be reduced as much as possible. Polyatomic interferences (PIs), formed by the heavy metals (HMs) from Hf to Bi are known to create the problems for Pu isotopic analyses, because even the relatively high resolution of a modern multicollector ICP-MS is not enough to separate Pu isotopes from this PIs in most of the cases. Desolvating nebulizers (DSN) (e.g. APEX and AridusII) reduce significantly the formation of PIs compare to the use of wet plasma. The purpose of this work was to investigate the rate of formation of PIs, produced by HMs, when high resolution MC ICP-MS with desolvating nebulizer was used for Pu isotopic analyses and to estimate the influence of the metals present in the sample on the results of analyses. The NU Plasma HR Multicollector and AridusII desolvating nebulizer were used in this investigation. This investigation was done for all Pu isotopes normally analyzed by ICP-MS, including ²⁴⁴Pu, with the exception of ²³⁸Pu, which most of the time can’t be analyzed by ICP-MS, because of the overwhelming presence of ²³⁸U in the solutions. The PI formation rates were determined and reported for all 12 HMs from Hf to Bi. Selected IAEA samples were scanned for the presence of HMs and the influence of HMs on the results of Pu isotopic analyses was evaluated. It was found that the implemented separation procedure provides sufficient separation of HM from Pu, although the effect of PIs on the measurement of low level isotopes like ²⁴¹Pu and ²⁴²Pu in some cases can still be observed.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1188890
• Report Number(s): PNNL-SA-104196; NN4009030
• Journal Information: Journal of Analytical Atomic Spectrometry, Journal Name: Journal of Analytical Atomic Spectrometry Journal Issue: 2 Vol. 30; ISSN JASPE2; ISSN 0267-9477
• Publisher: Royal Society of Chemistry
• Country of Publication: United States
• Language: English

Related Subjects

nebulizer
plutonium isotopic
polyatomic interferences