Comparison of factors affecting the accuracy of high‐precision magnesium isotope analysis by multi‐collector inductively coupled plasma mass spectrometry

High accuracy is the prerequisite for high-precision isotopic analysis.Here we evaluate how the presence of matrix elements, and mismatch between samples and standards in Mg concentration and acid molarity affect the accuracy of stable Mg isotopic analysis on Nu Plasma and IsoProbe multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) instruments.Our results show that these factors can lead to large (>1‰) deviation in the high-precision analysis of Mg isotopes. The degree and direction of these accuracy offsets can vary for different instruments, instrumental settings and different laboratories.Detailed tests and tight controls on these effects are thus needed for high-precision high-accuracy stable Mg isotopic analysis.