Preconcentration and Purification of Rare Earth Elements in Natural Waters Using Silica-Immobilized 8-Hydroxyquinoline and a Supported Organophosphorus Extractant

Abstract

8-Hydroxyquinoline immobilized on silica gel (silica3HQ) and RE-Spec, a supported organophosphorus extractant, were used to preconcentrate and purify rare earth elements (REEs) from natural waters prior to their determination by isotopedilution inductively coupled plasma mass spectrometry (IDICPMS). Preconcentration onto silica-8HQ is applicable to a wide range of trace metals, making it suitable for multielement ID-ICPMS studies. The silica-8HQ, RE-Spec technique concentrates REEs from 1 L or less of water into 1 mL of salt-free 0.1% nitric acid. The technique is rapid and has high REE yields (>80%) and low REE blanks ( 4 bg of Ba. We report a preconcentration and purification chemistry for the determination of rare earth elements (REEs) in natural waters by isotope-dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The sensitivity and multielement measurement capability of the ICPMS are ideally suited to the determination of dissolved metals, which are present at extremely low concentrations in natural waters. Furthermore, the ability to measure isotopic ratios accurately at the 0.1-1 %