Reevaluation of Th and U concentrations in marine sediment reference materials using isotope dilution MC-ICP-MS: towards the analytical improvements in dose rate estimation for luminescence dating

• Published in: Geosciences journal (Seoul, Korea) Vol. 17; no. 2; pp. 123 - 127
• Main Authors: Choi, Jeong-Heon, Ryu, Jong-Sik, Shin, Hyung Seon, Kim, Jeongmin, Cheong, Chang-sik
• Format: Journal Article
• Language: English
• Published: Heidelberg The Geological Society of Korea 01.06.2013; Springer Nature B.V; 한국지질과학협의회
• Subjects: Earth and Environmental Science; Earth Sciences; Heterogeneity; Isotopes; Letter; Luminescence; Marine geology; Marine sediments; Mass spectrometry; Sedimentary geology; Thorium; Uranium; 지질학; luminescence dating; CRMs; isotope dilution; MC-ICP-MS; dose rate
• ISSN: 1226-4806; 1598-7477
• DOI: 10.1007/s12303-013-0023-1

The thorium and uranium concentrations of four marine sediment reference materials (CRMs NIST 1646a, NRCC HISS-1, MESS-3 and PACS-2) were determined using isotope dilution-multiple collector-inductively coupled plasmas-mass spectrometry (ID-MC-ICP-MS), aiming at helping the assessment of reliability in dose rate estimation for luminescence dating. Quintuplicate analyses of the CRMs revealed their intrinsic heterogeneity in the concentration of both elements (up to 23% and 8% for thorium and uranium, respectively, in 2σ standard error level) for individual sub-samples of about 100 mg. The thorium and uranium concentrations of all CRMs determined in this study were significantly lower (up to 45%) than the provided or reported informative values, requiring reevaluation of their reference concentrations. The use of informative thorium and uranium concentrations in these CRMs as standard values for elemental analysis of unknown samples will result in overestimated dose rates, and thus age underestimation when applied to luminescence dating techniques.