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New thorium-229 standard reference material



Richard Essex, Jacqueline L. Mann, Ross W. Williams, William S. Kinman, Amelie Hubert, Megan E. Bennett


A new reference material, preliminarily designated as SRM 3059, was characterized for 229Th molality (mol•g-1) and thorium isotope amount ratios. This SRM is intended for use in nuclear forensic analyses as an isotope dilution mass spectrometry spike. The value and expanded uncertainty (k = 2) for the 229Th molality is (1.1498 ± 0.0016) • 10-10 mol • g-1 solution. The values and expanded uncertainty (k = 2) for the n(230Th)/n(229Th) ratio is (5.18 ± 0.26) • 10-5 and the n(232Th)/n(229Th) ratio is (3.815 ± 0.092) • 10-4.
Applied Radiation and Isotopes


thorium, isotope dilution mass spectrometry, nuclear forensics, radiochronometry, reference material


Essex, R. , Mann, J. , Williams, R. , Kinman, W. , Hubert, A. and Bennett, M. (2017), New thorium-229 standard reference material, Applied Radiation and Isotopes, [online], (Accessed June 22, 2024)


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Created July 26, 2017, Updated June 24, 2021