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Selective separation of elements and radioisotopes by ion exchange chromatography

Thesis (PhD)--Stellenbosch University, 2002. / 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 oxalic
acid - sulphuric acid mixtures were successfully determined. The equilibrium
distribution coefficients of these selected metal ions were determined in both 0.05 M
and 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 the
sorption behaviour of the selected metal ions were made by using MINEQL+, a
speciation 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. Two
component [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) and
Zr(IV)-Ta(V)-Yb(III)] mixtures on a 10 ml or 13 ml cation exchange resin in a variety
of 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 a
10 ml or 13 ml anion exchange resin in a variety of oxalic acid - sulphuric acid
mixtures were also successfully separated and studied. It was also shown how some
of the elution curves developed above could easily be adapted for radiochemical
separations.
Usin~ the relevant data from the above study, a separation for 68Gefrom a Ga20 target
was developed according to a method based on acid dissolution of the target and
chromatography on an anion exchange resin (Bio-Rad® AG1-X8). The separated
68Geshowed high radionuclidic purity and an acceptable chemical purity. / AFRIKAANSE OPSOMMING: Die ewewigsverdelingskoëffisiënte van 32 metaalione [Al(III), As(V), Cd(II), Ce(III),
Ce(IV), Co(II), Cr(III), Cu(II), Fe(III), Ga(III), Ge(IV), In(III), La(III), Mn(ll), Mo(VI),
Nb(V), Ni(ll), Pr(Ill), Sb(V), Sc(III), Se(IV), Sn(IV), Ta(V), Th(Ill), Te(IV), Ti(IV),
vrv; W(VI), Y(III), Yb(III), Zn(lI) en Zr(IV)] op 'n katioonruiler (Bio-Rad®
AG50W-X8) en 'n anioonruiler (Bio-Rad® AG1-X8) in veranderende oksaalsuurswaelsuurmengsels
is met welslae bepaal. Die ewewigsverdelingskoëffisiënte van
hierdie geselekteerde elemente is in beide 0.05 Men 0.25 M oksaalsuur by verskeie
konsentrasies swaelsuur (0.005 M, 0.05 M, 0.10 M, 0.25 M, 0.50 M, 1.00 M, 1.50 M
en 2.00 M) bepaal. Daar is gepoog om die sorpsiegedrag van die geselekteerde
metaalione te verklaar deur die gebruik van MINEQL+, 'n spesiëringmodelleringsprogram,
en die spesiëringsisteme vir AI(III), Cd(II), Co(II) en Zn(lI) in
veranderende oksaalsuur-swaelsuurmengsels is bepaal. Tweekomponent [Zr(IV)-
La(III); AI(III)-La(II!); Ga(III)-Zn(Il); As(V)-Zn(II); Cu(II)-Ce(IV); Ga(III)-Ce(IV);
Ge(IV)-Ce(Il!); Mo(VI)- Y(III); Nb(V)- Y(ll!); Ga(Ill)-Co(Il); As(V)-Co(lI) en Fe(III)-
Mn(II)] en driekomponent [Fe(III)-Ga(III)-Zn(ll) en Zr(IV)- Ta(V)- Yb(III)] mengsels
op 'n 10 ml of 13 ml katioonruilhars in 'n verskeidenheid oksaalsuurswaelsuurmengsels
is met welslae geskei. Tweekomponent [As(V)-Zr(IV); Co(II)-
Fe(III); Ni(Il)-Co(lI) en Ni(II)-Fe(III)] en driekomponent [Ni(II)-As(V)-Se(IV);
AI(III)-Zn(Il)-Ge(IV) en As(V)-Cu(II)-Ge(IV)] mengsels op 'n 10 ml of 13 ml
anioonruilhars in 'n verskeidenheid oksaalsuur-swaelsuurmengsels is ook met welslae
geskei en bestudeer. Daar is ook aangetoon hoe sommige van die elueringskrommes
wat hierbo ontwikkel is, maklik vir radiochemiese skeidings aangepas sou kon word.
Deur gebruik te maak van die relevante data uit die studie hierbo, is 'n skeiding vir
68Geuit 'n Ga20-teiken ontwikkel volgens 'n metode gebaseer op suurdissolusie van
die teiken en chromatografie op 'n anioonruilhars (Bio-Rad® AG1-X8). Die geskeide
68Gehet hoë radionukliedsuiwerheid en 'n aanvaarbare chemiese suiwerheid getoon.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53046
Date12 1900
CreatorsNaidoo, Clive
ContributorsVan der Walt, T. N., Raubenheimer, H. G., Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science.
PublisherStellenbosch : Stellenbosch University
Source SetsSouth African National ETD Portal
Languageen_ZA
Detected LanguageEnglish
TypeThesis
Format225 pages : illustrations
RightsStellenbosch University

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