Publication Date:
2019
Description:
Abstract
The lithium (Li) isotopes of carbonate can serve as important tools for assessing the palaeoclimate and palaeoenvironment. However, carbonate bulk rock samples are commonly mixtures of carbonate and silicate minerals, which require the complete digestion of the carbonate without digesting the silicate. Additionally, the low‐Li content (ng g−1 level) in carbonate provides an additional challenge. Hence, despite their wide applications, only a few carbonates have had their δ7Li values characterised, especially for carbonate reference materials, which hinders comparisons of the Li isotopes obtained in different laboratories and further applications of Li isotopes in geological studies. We aim to provide accurate and precise δ7Li values for commercial carbonate reference materials based on an evaluation of sample leaching and the Li purification method of carbonates, as well as the adoption of soft extraction and 1012 Ω amplifiers to increase the intensity/blank ratio and matrix effect on Li isotopes analysis. The accuracy and precision of the proposed procedure were verified by analysing synthetic carbonate samples and mono‐elemental Li solutions. With the developed method, we provide δ7Li values for eleven carbonate reference materials with a precision of ~ 0.4‰, and the accuracy of the δ7Li values is validated using the standard addition method.
This article is protected by copyright. All rights reserved.
Print ISSN:
1639-4488
Electronic ISSN:
1751-908X
Topics:
Geosciences
Permalink