A procedural development for the analysis of ^56/54Fe and ^57/54Fe isotope ratios with new generation IsoProbe MC-ICP-MS

Guilbaud, R., Ellam, R. , Butler, I.B., Gallagher, V. and Keefe, K. (2010) A procedural development for the analysis of ^56/54Fe and ^57/54Fe isotope ratios with new generation IsoProbe MC-ICP-MS. Journal of Analytical Atomic Spectrometry, 25(10), pp. 1598-1604. (doi: 10.1039/c004876c)

Abstract

We have developed a procedure for iron isotope analysis using a hexapole collision cell MC-ICP-MS which is capable of Fe isotope ratio analysis using two different extraction modes. Matrix effects were minimised and the signal-to-background ratio was maximised using high-concentration samples (~ 5μg Fe) and introducing 1.8 mL/min^-1 Ar and 2 mL/min H₂ into the collision cell to decrease polyatomic interferences. The use of large intensity on the faraday cups considerably decreases the internal error of the ratios and ultimately, improves the external precision of a run. Standard bracketing correction for mass bias was possible when using hard extraction. Mass bias in soft extraction mode seems to show temporal instability that makes the standard bracketing inappropriate. The hexapole rf amplitude was decreased to 50 % to further decrease polyatomic interferences and promote the transmission of iron range masses. We routinely measure Fe isotopes with a precision of ± 0.05 ‰ and ± 0.12 ‰ (2σ) for δ⁵⁶Fe and δ⁵⁷Fe respectively.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ellam, Professor Rob and Gallagher, Mr Vincent and Keefe, Mrs Kathleen
• Authors: Guilbaud, R., Ellam, R., Butler, I.B., Gallagher, V., and Keefe, K.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Journal of Analytical Atomic Spectrometry
• Journal Abbr.: J. Anal. At. Spectrom.
• Publisher: Royal Society of Chemistry
• ISSN: 0267-9477
• ISSN (Online): 1364-5544
• Published Online: 08 July 2010
• Copyright Holders: Copyright © 2010 Royal Society of Chemistry
• First Published: First published in Journal of Analytical Atomic Spectrometry 25(10):1598-1604
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher