Combined chemical separation of Lu, Hf, Rb, Sr, Sm and Nd from a single rock digest and precise and accurate isotope determinations of Lu-Hf, Rb-Sr and Sm-Nd isotope systems using Multi-Collector ICP-MS and TIMS

A combined procedure for separating Lu, Hf, Rb, Sr, Sm and Nd from a single sample digestion is presented in this paper. The procedure consists of the following four steps: (1) sample dissolution in a mixture of concentrated HF-HNO3-HClO4; (2) Lu and Hf separation from the Rb, Sr, LMREE and other matrix elements by HF-free extraction chromatography: (3) Rb, Sr and LMREE separation from other matrix elements using a cation-exchange resin; (4) Sm and Nd separation from others LMREE by extraction chromatography. Analytical feasibility, flexibility and reproducibility of Rb-Sr. Sm-Nd and Lu-Hf isotope systems are demonstrated for international standard solutions and Certified Reference Materials (CRMs). Results show good agreement with previously reported values by isotope dilution methods, indicating the technique has fewer problems in respect to well-known sample inhomogeneity of natural geological materials and demonstrating its potential application to the study of limited and precious terrestrial rocks or minerals (like peridotite, kimberlite and xenoliths) and extra-terrestrial samples (like lunar rock and meteorites). (C) 2009 Elsevier B.V. All rights reserved.