Distribution coefficients of 60 elements on TODGA resin: Application to Ca, Lu, Hf, U and Th isotope geochemistry

Ali Pourmand, Nicolas Dauphas

Research output: Contribution to journalArticle

85 Scopus citations

Abstract

Batch equilibration experiments are conducted to measure the distribution coefficients (Kd) of a large number of elements in nitric, nitric plus hydrofluoric, and hydrochloric acids on Eichrom TODGA extraction chromatography resin. The Kds are used to devise a multi-element extraction scheme for high-precision elemental and isotopic analyses of Ca, Hf, Lu, Th and U in geological materials, using high-purity lithium metaborate (LiBO2) flux fusion that allows rapid digestion of even the most refractory materials. The fusion melt, dissolved in nitric acid, is directly loaded to a TODGA cartridge on a vacuum chamber for elemental separation. An Ln-Spec cartridge is used in tandem with TODGA for Lu purification. The entire procedure, from flux digestion to preparation for isotopic analysis, can be completed in a day. The accuracy of the proposed technique is tested by measuring the concentrations of Ca (standard bracketing), Hf, Lu, Th and U (isotope dilution), and the isotopic composition of Hf in geostandards (USNM3529, BCR-2, BHVO-1, AGV-1 and AGV-2). All measurements are in excellent agreement with recommended literature values, demonstrating the effectiveness of the proposed analytical procedure and the versatility of TODGA resin.

Original languageEnglish (US)
Pages (from-to)741-753
Number of pages13
JournalTalanta
Volume81
Issue number3
DOIs
StatePublished - May 15 2010
Externally publishedYes

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Keywords

  • Distribution coefficient
  • Extraction chromatography
  • Flux fusion
  • Lu-Hf
  • TODGA
  • U-Th

ASJC Scopus subject areas

  • Analytical Chemistry

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