The lithium isotope composition of international rock standards

We present the results of analysis of the Li isotope composition of open oc ean seawater, nine international rock standards and a Cl chondrite. In addi tion, we suggest some modifications of the chemical preparation techniques for analysis of lithium isotopes in low concentration samples that give pre cise isotope ratios by thermal ionisation mass spectrometry (TIMs). The aim of this study is to provide a benchmark for ensuring the reliability of Li isotope data between different laboratories by TIMS and other isotope rati o techniques, including multi collector-inductively coupled plasma-mass spe ctrometry and ion probe. (C) 2000 Elsevier Science B.V. All rights reserved .