Determination of the isotopic composition of hafnium using MC-ICPMS

Abstract

Despite the numerous important applications of hafnium isotopes in geological science, and the advances in multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), hafnium still lacks calibrated measurements of its isotope ratios and, in turn, isotopic abundances and atomic weight. In this study, we determined the isotopic composition of hafnium in four commercial hafnium reagents, including a commonly used hafnium standard (JMC-475) and a NRC candidate isotopic reference material (HALF-1) by MC-ICPMS. The state-of-the-art regression model with NIST SRM 989 isotopic rhenium as calibrator was used to correct instrumental isotopic fractionation without reliance on other hafnium standards, normalizing isotope ratios, or exponential mass-bias fractionation model.