Adsorption and Preconcentration of Pd(II), Pt(IV), and Rh(III) using Anion‐Exchange Solid‐Phase Extraction Cartridges (SPE)

We would like to dedicate this paper to Prof. Manuel Aguilar in recognition of his long and distinguished contribution to the field of Solvent Extraction research.

Abstract

Abstract: The use of commercially available solid phase extraction (SPE) anion‐exchange cartridges for the separation and preconcentration of Pd(II), Pt(IV) and Rh(III) in chloride aqueous samples is described and characterised. Platinum Group Metals (PGMs) form anionic species in aqueous chloride solutions permitting their adsorption via an ion‐exchange mechanism by commercially available sorbents containing quaternary ammonium substituents or protonated aminopropyl groups. The difficulties associated with the extraction processes, interference of chloride ions in the case of Pd and Pt, and the low extraction efficiency in the case of Rh, are overcome modifying the metal speciation in the source solution by adding thiocyanate and tin chloride. These refined processes give quantitative metal adsorptions. The use of acidic thiourea solutions allows the quantitative recovery of Pd, Pt, and Rh in the case of the Isolute‐SAX cartridge. High preconcentration factors were obtained with Isolute‐NH2 and sodium chloride to elute Pd and Pt, and sodium phosphate solutions for Rh elution.

We would like to dedicate this paper to Prof. Manuel Aguilar in recognition of his long and distinguished contribution to the field of Solvent Extraction research.

Keywords:

• Palladium
• platinum
• rhodium
• solid‐phase extraction

ACKNOWLEDGEMENTS

This study was financed in part by the MEC (Spanish Ministry for Education and Science), project CTQQ2005‐09430‐C05‐03.

Notes

We would like to dedicate this paper to Prof. Manuel Aguilar in recognition of his long and distinguished contribution to the field of Solvent Extraction research.