An efficient Li dual-column system and high-precision Li isotope measurement of high matrix and low-Li samples by MC-ICP-MS

Abstract

Over the last decade, there has been a growing interest in using lithium (Li) isotopes in marine carbonates to trace chemical weathering and clay formation in the Earth’s history. Yet...

Purification of High Aluminum Content Samples for Rapid and Precise Analysis of Lithium Isotopes

“…1). 1,3,4,11,15,16,18,23,24,[26][27][28][29][30][31][32][33][34][35] However, interferences of the matrix elements on Li in MC-ICP-MS, particularly Al, may cause significant instrumental mass bias. 1,36,37 Thus, it is vital to completely separate Li from the matrix elements.…”

“…Previous studies employed single-column methods with a large height-to-diameter ratio 3,11,14,15,17,24,[26][27][28]31,32 or multiple columns to address Al tailing. 1,3,4,11,15,16,23,24,[26][27][28][29][30][31][32][33][34] Nevertheless, considerable time and steps were required to purify samples in these methods. The single-step method generally requires a large volume of cation-exchange resin (e.g., AG50W-X8 or -X12) and acid, 16,17,26,33,[38][39][40] increasing the risk of contamination.…”

“…In this study, we explored a novel method to remove the influence of Al tailing on the test within the premise of ensuring accuracy and single-column procedure. Compared with the less effective single-long-column methods for high Al samples, where 0.5 mol L -1 HCl was used as eluent, the proposed method, 4,17,26,28,29,33,34 which employed a mixed acid (0.5 mol L -1 HCl + 0.2 mol L -1 HF), 32,41 successfully separated lithium from matrix elements and HFSEs for various geological reference materials (e.g., BCR-2, BHVO-2, AGV-2, BIR-1a, RGM-2, JF-1, SCo-1, GSP-2, GSR-6, and GSR-8). The accuracy and precision of the Li isotope data with this purification procedure were evaluated with the measurements of well-studied geological reference materials, whose δ 7 Li values have been reported by international laboratories.…”