Group separation of rare earth elements by liquid-liquid extraction for the neutron activation analysis of silicate rocks

Rare earth elements are isolated as a group from neutron activated rock samples by a new radiochemical procedure based on extraction with thenoyltrifluoracetone/phenanthroline in CHCl₃. The procedure consists of three extraction steps, obviates the use of anactive carriers and gives practically quantitative chemical yields, thereby avoiding fractionation of the individual rare earths. Details of the dissolution, chemical separations and counting procedure are given togther with an analysis of BCR-1.