Optimized switch-over between CHNS abundance and CNS isotope ratio analyses by elemental analyzer-isotope ratio mass spectrometry : application to six geological reference materials
Abstract
Rationale : Elemental abundances and isotopic ratios of carbon, nitrogen, sulfur and hydrogen have become important tools for reconstructing the evolution of Earth and life over geologic timescales, requiring accurate and precise analytical methods with high sample throughput. However, these measurements may require separate instruments for each task, such as an elemental analyzer (EA) with a thermal conductivity detector (TCD) for elemental abundances and an EA interfaced with a mass spectrometer for isotopic ratios. Methods : To improve sample throughput and laboratory up‐time, we developed a switch that allows converting an EA IsoLink™ system from a standalone mode using only a TCD to a mode for isotope ratio mass spectrometry (IRMS) within minutes. This permits accurate measurements of elemental abundances and isotopic ratios with high throughput and lower cost. We validated this method with six shale standards from the US Geological Survey (USGS) and compared our abundance data with those from another laboratory. Results : Our results show that (a) abundance data agree well between the different laboratories and setups; (b) reproducible isotopic data can be obtained before and after the switch‐over from EA standalone mode; and (c) the USGS rock standards cover a wide range in CHNS abundances and CNS isotopes, making them ideal reference materials for future geochemical studies. Conclusions : This ideal analytical setup has the advantage that abundance measurements can be performed to determine optimal sample amounts for later isotopic analyses, ensuring higher data quality. Our setup eliminates the need for a separate EA while freeing up the mass spectrometer for other tasks during abundance measurements.
Citation
Stueeken , E , de Castro , M , Krotz , L , Brodie , C , Iammarino , M & Giazzi , G 2020 , ' Optimized switch-over between CHNS abundance and CNS isotope ratio analyses by elemental analyzer-isotope ratio mass spectrometry : application to six geological reference materials ' , Rapid Communications in Mass Spectrometry , vol. 34 , no. 18 , e8821 . https://doi.org/10.1002/rcm.8821
Publication
Rapid Communications in Mass Spectrometry
Status
Peer reviewed
ISSN
0951-4198Type
Journal article
Rights
Copyright © 2020 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Description
EES thanks Tommaso Di Rocco for technical assistance and acknowledges start-up funds from the School of Earth & Environmental Sciences, St Andrews.Collections
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