Thallium mass fraction and stable isotope ratios of sixteen geological reference materials

Brett, A.; Prytulak, J.; Hammond, S.J.; Rehkamper, M.

Abstract

Thallium stable isotope ratio and mass fraction measurements were performed on sixteen geological reference materials spanning three orders of magnitude in thallium mass fraction, including both whole‐rock and partially separated mineral powders. For stable isotope ratio measurements, a minimum of three independent digestions of each reference material was obtained. High‐precision trace element measurements (including Tl) were also performed for the majority of these RMs. The range of Tl mass fractions represented is 10 ng g−1 to 16 μg g−1, and Tl stable isotope ratios (reported for historical reasons as ε205Tl relative to NIST SRM 997) span the range ‐4 to +2. With the exception – attributed to between‐bottle heterogeneity – of G‐2, the majority of data are in good agreement with published or certified values, where available. The precision of mean of independent measurement results between independent dissolutions suggests that, for the majority of materials analysed, a minimum digested mass of 100 mg is recommended to mitigate the impact of small‐scale powder heterogeneity. Of the sixteen materials analysed, we therefore recommend for use as Tl reference materials the USGS materials BCR‐2, COQ‐1, GSP‐2 and STM‐1; CRPG materials AL‐I, AN‐G, FK‐N, ISH‐G, MDO‐G, Mica‐Fe, Mica‐Mg and UB‐N; NIST SRM 607 and OREAS14P.

Citation

Brett, A., Prytulak, J., Hammond, S., & Rehkamper, M. (2018). Thallium mass fraction and stable isotope ratios of sixteen geological reference materials. Geostandards and Geoanalytical Research, 42(3), 339-360. https://doi.org/10.1111/ggr.12215

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2018
• Online Publication Date: May 24, 2018
• Publication Date: Sep 1, 2018
• Deposit Date: Apr 26, 2018
• Publicly Available Date: May 24, 2019
• Journal: Geostandards and Geoanalytical Research
• Print ISSN: 1639-4488
• Electronic ISSN: 1751-908X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 42
• Issue: 3
• Pages: 339-360
• DOI: https://doi.org/10.1111/ggr.12215
• Public URL: https://durham-repository.worktribe.com/output/1328230