Application of Strongly Basic Monodisperse Anion Exchangers in Sorption and Separation of Y(edta)' from Nd (edta)' Complexes

摘要

The rare earth element complexes with EDTA of the Ln(edta)- type exhibit an unusual sequence of affinity for the polystyrene anion exchangers in the H2edta2" from: Sm (III) > Eu (III) > Gd (III) > Nd (HI) > Pr (HI) > Tb (III) > Ce (III) > Dy (111) > La (III) > Ho (III) > Y (III) > Er (III) > Sc (III) > Tm (III) > Yb (III) > Lu(IIl). Taking into account the position of Y(III) and Nd(III) in the affinity series, for the monodisperse, strongly basic anion exchangers Lewatit Monoplus M 500, Lewatit MonoPlus M 600 and Lewatit Monoplus MP 500 the weight (D) and bed (Dv) distribution coefficients of these complexes and also the working (Cn) and the total (C() ion exchange capacities were determined in the aqueous and H2O-polar organic solvents (methanol, ethanol, propanol or acetone) systems Based on these values the purification of Y(III) from Nd(IlI) on these anion exchangers was studied, Application of mixed solvents in the anion exchange of metal complexes has increased considerably the number of possible separations and in most cases distribution coefficients of the above mentioned lanthanide complexes in the mixed systems are larger than those in the aqueous solutions The best result of Y(III) purification from Nd(III) was obtained using monodisperse, strongly basic, gel polystyrene anion exchanger Lewatit MonoPlus M 500 in the 20% (v/v) methanol system.