William F Defliese1,2, Aradhna Tripati3,4. 1. Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, USA. 2. School of Earth and Environmental Sciences, The University of Queensland, QLD, St Lucia, Australia. 3. Department of Earth, Planetary, and Space Sciences, Department of Atmospheric and Oceanic Sciences, Institute for the Environment and Sustainability, University of California, Los Angeles, CA, USA. 4. European Institute of Marine Sciences (IUEM), Université de Brest, Domaines Océaniques, Rue Dumont D'Urville, and IFREMER, Plouzané, France.
Abstract
RATIONALE: Carbonate clumped isotope geothermometry is being increasingly used in multiple disciplines in the geosciences. However, potential interlaboratory issues are arising from different standardization procedures that may contribute to the multiple Δ47 -temperature calibrations reported in the literature. We investigate this issue by comparing a common temperature calibration sample set across three different mass spectrometers, using multiple standardization methods. METHODS: The same temperature calibration sample set was analyzed on three different mass spectrometers. Several standardization methods were utilized, including the use of carbonate versus gas standards, and different types of background correction were applied to the raw data. RESULTS: All standardization types applied resulted in statistically indistinguishable Δ47 -temperature slopes, with the exception of standardization calculations that did not correct for background effects. Some instruments and standardizations showed different intercepts relative to each other. The use of carbonate standards improved comparability between different instruments relative to gas standards. CONCLUSIONS: Our results show that background effects are the largest factor potentially affecting Δ47 results, and there may be an improvement in interlaboratory precision using carbonate standards. Critically, all techniques used for standardizing Δ47 results converge on a common slope as long as background effects are properly corrected. The use of carbonate standards is recommended as a component of standardization procedures.
RATIONALE: Carbonate clumped isotope geothermometry is being increasingly used in multiple disciplines in the geosciences. However, potential interlaboratory issues are arising from different standardization procedures that may contribute to the multiple Δ47 -temperature calibrations reported in the literature. We investigate this issue by comparing a common temperature calibration sample set across three different mass spectrometers, using multiple standardization methods. METHODS: The same temperature calibration sample set was analyzed on three different mass spectrometers. Several standardization methods were utilized, including the use of carbonate versus gas standards, and different types of background correction were applied to the raw data. RESULTS: All standardization types applied resulted in statistically indistinguishable Δ47 -temperature slopes, with the exception of standardization calculations that did not correct for background effects. Some instruments and standardizations showed different intercepts relative to each other. The use of carbonate standards improved comparability between different instruments relative to gas standards. CONCLUSIONS: Our results show that background effects are the largest factor potentially affecting Δ47 results, and there may be an improvement in interlaboratory precision using carbonate standards. Critically, all techniques used for standardizing Δ47 results converge on a common slope as long as background effects are properly corrected. The use of carbonate standards is recommended as a component of standardization procedures.
Authors: Deepshikha Upadhyay; Jamie Lucarelli; Alexandrea Arnold; Randy Flores; Hayley Bricker; Robert N Ulrich; Gregory Jesmok; Lauren Santi; William Defliese; Robert A Eagle; Hannah M Carroll; Jesse Bloom Bateman; Victoria Petryshyn; Sean J Loyd; Jianwu Tang; Antra Priyadarshi; Ben Elliott; Aradhna Tripati Journal: Rapid Commun Mass Spectrom Date: 2021-07-26 Impact factor: 2.586