A straightforward separation scheme for the concomitant isolation of Lu, Hf, Sm,and Nd prior to isotope ratio and isotope dilution measurements following sampledecomposition by Lithium metaborate fusion or Hydrofluoric acid dissolution

• Published in: Geochemical journal Vol. 52
• Main Authors: Beranoaguirre, Aratz, Pin, Christian, Sánchez-Lorda, M.E., Pronost, Julie, de Madinabeitia, S. García, David, Karine, Gil-Ibarguchi, J.I.
• Format: Journal Article
• Language: English
• Published: The Geochemical Society of Japan 2018
• Subjects: Earth Sciences; Geochemistry; Sciences of the Universe; Lu-Hf; chromatography; silicates; Sm-Nd; isotope dilution-mass spectrometry
• ISSN: 0016-7002
• DOI: 10.2343/geochemj.2.0535

A robust method is described allowing the sequential separation of Hf and the lanthanides from matrix elements ofsilicate rocks or minerals. This is based on a single chromatographic column filled with the conventional cation-exchangeDowexAG50W-X8 resin, and hydrochloric, nitric and sulfuric acids as eluting agents. Samples can be processed followingthe same column protocol, irrespective whether they were decomposed by high temperature fusion with LiBO2 (ensuringa thorough sample/tracer isotopic equilibration in the molten glass, in case the isotope dilution method is used), or byhydrofluoric acid dissolution. The hafnium fraction separated in this way is ready for isotope ratio measurements by MCICP-MS, while the REEs are further processed by extraction chromatography for isolating Nd, Sm, and Lu, in view ofTIMS and MC-ICP-MS analyses. The precision and accuracy of the method were evaluated by repeat analyses of fourgeological Reference Materials covering a range of silicate rock compositions.