High-precision Sr and Nd isotope characterization of BHVO-2 reference material by thermal ionization mass spectrometry

Abstract

Rationale: Control over accuracy and precision in isotope geochemical analysis is highly necessary for reliable results. Use of reference materials in Sr and Nd isotope geochemistry provides a means of validating optimal sample preparation and instrument configurations.

Methods: A comprehensive data set of Sr and Nd isotope analyses of BHVO-2 reference material was obtained by thermal ionization mass spectrometry (TIMS). The intention is to assist other researchers in evaluating isotopic analyses of geological samples with similar chemical matrix.

Results: 87Sr/86Sr isotope ratios analyzed in BHVO-2 reference material over 88 replicas from 2015 to the present provide an average value of 0.703485 ± 0.000024. In turn, 143Nd/144Nd isotope ratios in 62 replicas show an average value of 0.512978 ± 0.000012. The high number of analyses here presented ensures a high reproducibility over time in a non-certified material for isotopic analysis of these two elements.

Conclusions: This high precision and reproducibility of Sr and Nd analysis by TIMS provide a basis for validation of analytical processes in the absence of certified reference materials and support the correlation of isotopic results between laboratories and the overall improvement in the interpretation of isotope results for geological, environmental and archeological samples.