Journal of Radioanalytical and Nuclear Chemistry

, Volume 322, Issue 3, pp 1593–1604 | Cite as

Preparation and calibration of a 231Pa reference material

  • Richard M. EssexEmail author
  • Ross W. Williams
  • Kerri C. Treinen
  • Ronald Collé
  • Ryan Fitzgerald
  • Raphael Galea
  • John Keightley
  • Jerome LaRosa
  • Lizbeth Laureano-Pérez
  • Svetlana Nour
  • Leticia Pibida


A 231Pa reference material has been characterized for amount of protactinium. This reference material is primarily intended for calibration of 233Pa tracers produced for 235U–231Pa model age measurements associated with nuclear forensics and nuclear safeguards. Primary measurements for characterization were made by isotope dilution mass spectrometry of a purified 231Pa solution using a 233Pa isotopic spike. The spike was calibrated by allowing multiple aliquots of the 233Pa spike solution to decay to 233U and then measuring the ingrown 233U by isotope dilution mass spectrometry using a certified uranium assay and isotopic standard as a reverse-spike. The new 231Pa reference material will simplify calibration of the 233Pa isotope dilution spikes, provide metrological traceability, and potentially reduce the overall measurement uncertainty of model ages.


Isotope dilution mass spectrometry Nuclear forensics 231Pa 233Pa Radiochronometry Reference material 



Roger Henderson at LLNL performed the initial purification of the 231Pa that was used as the starting material for this project. His expertise and assistance is gratefully acknowledged. Funding for project activities at LLNL and at NIST was provided by the United Stated Department of Homeland Security. Analyses performed at NRC and NPL were internally funded.

Compliance with ethical standards

Conflict of interest

All authors declare that they have no conflict of interest.

Human and animal rights

This article does not contain any studies with human or animal subjects performed by the any of the authors.


  1. 1.
    Cheng H, Edwards RL, Murrell MT, Benjamin TM (1998) Uranium-thorium-protactinium dating systematics. Geochim Cosmochim Acta 62:3437–3452CrossRefGoogle Scholar
  2. 2.
    Morgenstern A, Apostolidis C, Mayer K (2002) Age determination of highly enriched uranium: separation and analysis of 231Pa. Anal Chem 74:5513–5516CrossRefGoogle Scholar
  3. 3.
    Eppich GR, Williams RW, Gaffney AM, Schorzman KC (2013) 235U–231Pa age dating of uranium materials for nuclear forensic investigations. J Anal At Spectrom 28:666–674CrossRefGoogle Scholar
  4. 4.
    Varga Z, Nicholl A, Wallenius M, Mayer K (2018) Measurement of the 231Pa/235U ratio for the age determination of uranium materials. J Radioanal Nucl Chem 318:1565–1571CrossRefGoogle Scholar
  5. 5.
    Pickett DA, Murrell MT, Williams RW (1994) Determination of femtogram quantities of protactinium in geologic samples by thermal ionization mass spectrometry. Anal Chem 66:1044–1049CrossRefGoogle Scholar
  6. 6.
    Regelous M, Turner SP, Elliot TR, Rostami K, Hawkesworth CJ (2004) Measurement of femtogram quantities of protactinium in silicate rock samples by multicollector inductively coupled plasma mass spectrometry. Anal Chem 76:3584–3589CrossRefGoogle Scholar
  7. 7.
    Sill CW (1966) Preparation of protactinium-233 tracer. Anal Chem 38(11):1458–1463CrossRefGoogle Scholar
  8. 8.
    Bourdon B, Joron J-L, Allège CL (1999) A method for 231Pa analysis by thermal ionization mass spectrometry in silicate rocks. Chem Geol 157:147–151CrossRefGoogle Scholar
  9. 9.
    Keegan E, Stopic A, Griffiths G (2014) Protactinium-231 (231Pa) measurement for isotope chronometry in nuclear forensics. IAEA-CN-218-12.
  10. 10.
    Naperstkow Z, Moore K, Szames D, Varlow C, Armstrong AF, Galea R (2018) Production and standardization of an on-demand protactinium-233 tracer. J Radioanal Nucl Chem 318:703–709CrossRefGoogle Scholar
  11. 11.
    BIPM (2011) Monograph 5: Table of radionuclides, 6-A: 22:242. Accessed 11 March 2019
  12. 12.
    BIPM (2010) Monograph 5: table of radionuclides, 5-A: 22:244. Accessed 11 March 2019
  13. 13.
    Fitzgerald R, Pibida L (2018) Primary standardization of the massic activity of a 233Pa solution. J Radioanal Nucl Chem 318:149–155CrossRefGoogle Scholar
  14. 14.
    Galea R (2018) Summary of results from the NRC standardization of LLNL supplied 233Pa and 231Pa. Internal Report, National Research Council Canada, Ottawa, CanadaGoogle Scholar
  15. 15.
    Fitzgerald R, Colle R, LaRosa J, Nour S, Laureano-Perez L, Pidiba L (2018) Massic activity of a protactinium-233 solution determined by two methods. (Abstract 361) MARC XI, April 8–13, 2018, Kailua-Kona, Hawaii.
  16. 16.
    Wilson RE (2014) Retrieval and purification of the an aged 231Pa source from its decay daughters. Radiochim Acta 102(6):505–511CrossRefGoogle Scholar
  17. 17.
    Treinen KC, Gaffney AM, Rolison JM, Samperton KM, McHugh KC, Miller ML, Williams RW (2018) Improved protactinium spike calibration method applied to 231Pa–235U age-dating of certified reference materials for nuclear forensics. J Radioanal Nucl Chem 318:209–219CrossRefGoogle Scholar
  18. 18.
    NNDC, 2011, Nuclear Wallet Cards. National Nuclear Date Center, Brookhaven National Laboratory, Accessed 11 March 2019
  19. 19.
    BIPM, 2004, Monograph 5: Table of Radionuclides, 2-A: 151:242. Accessed 11 March 2019
  20. 20.
    CRM 112-A (2010) Certificate of analysis CRM 112-A uranium (normal) metal assay isotopic standard. NBL Program Office, Argonne, IL.
  21. 21.
    Richter S, Goldberg SA (2003) Improved techniques for high accuracy isotope ratio measurements of nuclear materials using thermal ionization mass spectrometry. Int J Mass Specctrom 229:181–197CrossRefGoogle Scholar
  22. 22.
    CRM U010, 2008, Certificate of Analysis CRM U010 uranium isotopic standard. NBL Program Office, Argonne, IL.
  23. 23.
    CRM U005-A, 2008, Certificate of Analysis CRM U005-A uranium isotopic standard. NBL Program Office, Argonne, IL.
  24. 24.
    CRM 129-A, 2003, Certificate of Analysis CRM 129-A uranium oxide (U3O8) assay and isotopic standard, NBL Program Office, Argonne, IL.
  25. 25.
    JCGM-Joint Committee for Guides in Metrology, 2008, Evaluation of measurement data – Guide to the expression of uncertainty in measurement. JCGM 100, 2008 (E/F)Google Scholar
  26. 26.
    Taylor BN, Kuyatt CE (1994) Guideline for evaluating and expressing the uncertainty of NIST measurement results. National Institute of Standards and Technology, Gaithersburg, MD, Technical Note 1297Google Scholar
  27. 27.
    JCGM-Joint Committee for Guides in Metrology (2012) International vocabulary of metrology-basic and general concepts and terms (VIM). JCGM 200:2012Google Scholar
  28. 28.
    ISO, 2017, International Organization for Standardization, Reference materials - Guidance for characterization and assessment of homogeneity and stability. ISO GUIDE 35:2017 (E)Google Scholar
  29. 29.
    ISO, 2016, International Organization for Standardization, General requirements for the competence of reference material producers. ISO 17034:2016 (E)Google Scholar
  30. 30.
    Kirby, H. W., 1959, The Radiochemistry of Protactinium. National Academy of Sciences National Research Council, Nuclear Series, (NAS-NS 3016)Google Scholar
  31. 31.
    Morss LR, Edelstein N, Fuger J, Katz JJ (2011) The chemistry of the actinide and transactinide elements. Springer, DordrechtCrossRefGoogle Scholar
  32. 32.
    De Bièvre P, Peiser HS (1993) Basic equations and uncertainties in isotope-dilution mass spectrometry for traceability to SI of values obtained by this primary method. Fresenius J Anal Chem 359:523–525Google Scholar
  33. 33.
    Milton MJT, Quinn TJ (2001) Primary methods for the measurement of amount of substance. Metrologia 38:289–296CrossRefGoogle Scholar
  34. 34.
    Albarède F, Telouk P, Blichert-Toft J, Boyet M, Agraneir A, Nelson B (2004) Precise and accurate isotopic measurements using multiple-collector ICPMS. Geochim Cosmochim Acta 68:2725–2744CrossRefGoogle Scholar

Copyright information

© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2019

Authors and Affiliations

  • Richard M. Essex
    • 1
    Email author
  • Ross W. Williams
    • 2
  • Kerri C. Treinen
    • 2
  • Ronald Collé
    • 1
  • Ryan Fitzgerald
    • 1
  • Raphael Galea
    • 3
  • John Keightley
    • 4
  • Jerome LaRosa
    • 1
  • Lizbeth Laureano-Pérez
    • 1
  • Svetlana Nour
    • 1
  • Leticia Pibida
    • 1
  1. 1.National Institute of Standards and TechnologyGaithersburgUSA
  2. 2.Lawrence Livermore National LaboratoryLivermoreUSA
  3. 3.Ionizing Radiation Standards, National Research CouncilOttawaCanada
  4. 4.National Physical LaboratoryTeddingtonUK

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