Determination of Sr–Nd–Pb Isotopic Ratios of Rock Reference Materials Using Column Separation Techniques and TIMS

Hui Je Jo,Taehoon Kim,Go-Eun Kim,Won Myung Choi,Hyo Min Lee

doi:10.3390/separations8110213

Hui Je Jo, Taehoon Kim + Show 3 more

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https://doi.org/10.3390/separations8110213

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Abstract

Thermal ionization mass spectrometry (TIMS) can provide highly accurate strontium (Sr), neodymium (Nd), and lead (Pb) isotope measurements for geological and environmental samples. Traces of these isotopes are useful for understanding crustal reworking and growth. In this study, we conducted a sequential separation of Sr, Nd, and Pb and subsequently measured the 87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios of 13 widely used rock certified reference materials (CRMs), namely BCR-2, BHVO-2, GSP-2, JG-1a, HISS-1, JLk-1, JSd-1, JSd-2, JSd-3, LKSD-1, MAG-1, SGR-1, and 4353A, using TIMS. In particular, we reported the first isotopic ratios of Sr, Nd, and Pb in 4353A, Sr and Nd in HISS-1 and SGR-1, and Sr in JLk-1, JSd-2, JSd-3, and LKSD-1. The Sr–Nd–Pb isotopic compositions of most in-house CRMs were indistinguishable from previously reported values, although the Sr and Pb isotopic ratios of GSP-2, JSd-2, JSd-3, and LKSD-1 obtained in different aliquots and/or batches varied slightly. Hence, these rock reference materials can be used for monitoring the sample accuracy and assessing the quality of Sr–Nd–Pb isotope analyses.

Highlights

In geosciences, radiogenic isotopic ratios, combined with geochemical and stable isotope data, are used to determine the ages of terrestrial and extraterrestrial rocks and to understand geological processes and environments [1]
We conducted a sequential separation of Sr, Nd, and Pb, subsequently measured several aliquots of rock reference materials, investigated the reproducibility of this method in Sr–Nd–Pb isotope analyses, and determined the Sr–Nd–Pb isotopic ratios of in-house certified reference materials (CRMs) using Thermal ionization mass spectrometry (TIMS)
Stream (JSd-1, JSd-2, and JSd-3), lake (JLk-1 and LKSD-1), and marine (HISS-1) sediments were obtained from the Geological Survey of Japan (GSJ), the Canadian Certified Reference Material Programme, and the National Research Council

Summary

Introduction

Radiogenic isotopic ratios, combined with geochemical and stable isotope data, are used to determine the ages of terrestrial and extraterrestrial rocks and to understand geological processes and environments [1]. In geochemical research, including age dating, crustal evolution, and tracing pollutant origins, isotopic ratios are measured using high-precision analysis equipment, such as thermal ionization mass spectrometry (TIMS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) equipped with a laser ablation system. Differences in Sr isotopic compositions have been found between new reference materials and their original counterparts [41] This is probably caused by sample heterogeneity and contamination during sample, chemical, and analytical processing. We conducted a sequential separation of Sr, Nd, and Pb, subsequently measured several aliquots of rock reference materials, investigated the reproducibility of this method in Sr–Nd–Pb isotope analyses, and determined the Sr–Nd–Pb isotopic ratios of in-house CRMs using TIMS

Materials and Methods

TIMS Sr–Nd–Pb Isotope Analyses

Results and Discussion