Mutual separation of heavy lanthanoid elements and yttrium by high-speed countercurrent chromatography

The mutual separation of heavy lanthanoid elements and yttrium was performed by high-speed countercurrent chromatography (CCC) provided with a multilayer coiled column containing a toluene solution of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester. The rare-earth elements were chromatographically eluted by a mobile phase with a stepwise gradient of the acid concentration. The separation of rare-earth elements including yttrium after continuous-flow enrichment into the stationary phase from a large volume of a sample solution was also accomplished with sufficient resolution.