SEPARATION OF LANTHANIDE SERIES ELEMENTS IN MARINE FE-MN CRUSTS BY ION-EXCHANGE CHROMATOGRAPHY AND DETERMINATION BY ICP/AES

A method is described for the separation of lanthanide series elements (REE) from major matrix components of deep-sea ferromanganese crusts using cation-exchange chromatography. The samples are digested in concentrated mineral acids, evaporated to near dryness, and redissolved in 0.5 N HCl. Solutions are passed through Bio-Rad AG50W-X8 strong cation-exchange resin in the H+ form. Major (Fe and Mn) and minor constituents (Al, Co, Cu, Ni, Ca, and Mg) are eluted with 1.7 or 2.0 N HCl; the REE are then eluted from the resin with 4.0 or 6.0 N HCl. Only Ba is not separated and coelutes from the resin with the REE. The method quantitatively separates the lanthanides from most matrix constituents and greatly facilitates their rapid sequential analysis by ICP/AES. The method has been shown to yield accurate and precise analyses of ferromanganese minerals for their REE content in the U.S. Geological Survey standard Fe-Mn nodule A-1 and has been applied to Fe-Mn crusts from our collection. © 1990, Taylor & Francis Group, LLC. All rights reserved.