Determination of rare earth elements and yttrium in rocks by inductively coupled plasma atomic emission spectrometry after separation by organic solvent extraction

Abstract

Solvent extraction with trioctylphosphine oxide was used for the separation of rare earth elements (REE) and yttrium (Y) from geological samples decomposed by HF plus H₂SO₄ followed by alkaline fusion of the dry residue. The REE and Y were then measured by inductively coupled plasma atomic emission spectrometry after back-extraction into dilute HCl. Scandium, which is not back-extracted, can be measured in the organic phase. The separation procedure is more expeditious than ion-exchange chromatography.