Selective separation of elements and radioisotopes by ion exchange chromatography

[摘要] ENGLISH ABSTRACT: The equilibrium distribution coefficients of 32 metal ions [Al(llI), As(V), CdïIl),Ce(III), Ce(IV), Co(n), Cr(III), Cu(II), Fe(III), Ga(III), Ge(IV), !n(III), La(III), Mn(II),Mo(VI), Nb(V), Ni(II), Pr(III), Sb(V), Sc(III), Se(IV), Sn(IV), Ta(V), Tb(III), Te(IV),Ti(IV), Vev), W(VI), Y(III), Yb(III), Zn(lI) and Zr(IV)] on a cation exchanger (Bio-Rad® AG50W-X8) and an anion exchanger (Bio-Rad® AG1-X8) in varying oxalicacid - sulphuric acid mixtures were successfully determined. The equilibriumdistribution coefficients of these selected metal ions were determined in both 0.05 Mand 0.25 M oxalic acid at various concentrations of sulphuric acid (0.005 M, 0.05 M,0.10 M, 0.25 M, 0.50 M, 1.00 M, 1.50 M and 2.00 M). Attempts to explain thesorption behaviour of the selected metal ions were made by using MINEQL+, aspeciation modelling program, and the speciation systems for AI(III), Cd(II), Co(II)and Zn(lI) in varying oxalic acid - sulphuric acid mixtures were determined. Twocomponent [Zr(IV)-La(III); AI(III)-La(III); Ga(IlI)-Zn(II); As(V)-Zn(II); Cu(II)-Ce(IV); Ga(III)-Ce(IV); Ge(IV)-Ce(III); Mo(VI)- Y(III); Nb(V)- Y(III); Ga(III)-Co(II);As(V)-Co(lI) and Fe(III)-Mn(II)] and three component [Fe(III)-Ga(III)-Zn(lI) andZr(IV)-Ta(V)-Yb(III)] mixtures on a 10 ml or 13 ml cation exchange resin in a varietyof oxalic acid - sulphuric acid mixtures were successfully separated. Two component[As(V)-Zr(IV); Co(II)-Fe(III); Ni(II)-Co(lI) and Ni(II)-Fe(III)] and three component[Ni(II)-As(V)-Se(IV); AI(III)-Zn(II)-Ge(IV) and As(V)-Cu(II)-Ge(IV)] mixtures on a10 ml or 13 ml anion exchange resin in a variety of oxalic acid - sulphuric acidmixtures were also successfully separated and studied. It was also shown how someof the elution curves developed above could easily be adapted for radiochemicalseparations.Usin~ the relevant data from the above study, a separation for 68Gefrom a Ga20 targetwas developed according to a method based on acid dissolution of the target andchromatography on an anion exchange resin (Bio-Rad® AG1-X8). The separated68Geshowed high radionuclidic purity and an acceptable chemical purity.

[发布机构] Stellenbosch University