Routine isotopic analysis of iron by HR-MC-ICPMS: How precise and how accurate?

High-temperature isotopic variations documented in natural materials span a narrow range and call for precise and accurate isotopic analyses. Precisions better than similar to 0.03 parts per thousand (95% confidence interval) for delta(56)Fe have been obtained by High-Resolution Multi-Collector Inductively Coupled Plasma Mass Spectrometry (HR-MC-ICPMS). Whether these uncertainties encompass all sources of error has not been carefully evaluated. The current study examines all parameters that can affect accuracy and precision of Fe isotopic measurements by HR-MC-ICPMS. It is demonstrated that accurate delta(56)Fe measurements can be routinely achieved within the quoted uncertainties. (C) 2008 Elsevier B.V. All rights reserved.