Separation and determination of rare earth elements by Dowex 2-X8 resin using sodium trimetaphosphate as elution agent.

The distribution coefficients of rare earth elements and thorium with Dowex 2-X8, 200-400 mesh, a strongly basic anion-exchange resin, have been determined regarding four different concentrations of sodium trimetaphosphate (3 x 10(-3), 5 x 10(-3), 7 x 10(-3) and 0.01 M). The separation of the rare earths and thorium obtained from an Australian monazite has been investigated by anion-exchange chromatography with sodium trimetaphosphate concentration gradient on a Dowex 2-X8 ion-exchange columns. The order of elution of the elements was the reverse of the order of elution of the same elements on Dowex 1 resin. The elution was investigated using 5 mg and 250 mg samples. In the separation of 5 mg samples, all elements were separated in 29 min. It has been seen that the elution peaks are narrow, tailing effects are very small, Dy and Y are well separated. Qualitative and quantitative determinations were realized by spectrofluorometry.