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Distribution coefficients for twelve elements in oxalic acid medium on a strong anion-exchange resin
Analytica Chimicn Ada El%wicr Publishing Company, Amstcrdxn Printed in The Nct.hcrlPnds
DISTRIBUTION ACiD MEDIUM
COEFFICIENTS ON A STRONG
67
FOR TWELVE ANION-EXCHANGE
ELEMENTS RESIN
IN
OXALIC
Systematic surveys of the behaviour of elements on a strong base anionphosphoric4, exchange resin have been reported for hydrochloric 1, nitri&,hydrofluoric”, sulfuric acid”, and hydrochloric-hydrofluoricap7, nitric-hydrofluoric*vo and sulfurichydrofluoric acid mixtures 0. The adsorption characteristics in the above-mentioned mineral acids are now always applicable to separation techniques,
OF
THE
DISTRII3UTLO3i
COXSTASTS
The adsorbabilities are expressed as weight distribution coefficients, ICI, (axn~~unt per Q dry resin~amount per ml of solution). They can be determined by batch’” or column methods. When column techniques are used, either the clution chromatographic or the break-through method 13914can be applied. Furthermore, for the determination of large distribution coefficients, use can be made of the preloaded column techniquei4ei5. In this study, small Kn values were calculated from the corrected peak elution volume, I/moX. i.e. the volume of eluant required to elute the maximum of the elution band, by the following expression 1s~12 e*(Vm,,/V-i)=K~
(1)
where V =total volume of the column (height x cross-sectional area), ,g=specific volume of the exchanger, and i =void fraction of the column. Small aliquots of so-IOO p1 of the tracer solution containing the ion under T
**
Research associate of the N.F.W.0, Research associate of the I. I. K.W. Arrat.
Claim.
A&r.
42 (rgG8) 67-77
G8
I:. I>ECORTJ?,P.
VAN
DEN
WINKEL,
A.
SPEECKB,
J.
HOSTE
investigation, were adsorl~ecl rJn ttle top of the column, after the resin had been pretreated with the appropriate oxalic acid solution. Columns of cross-sections ranging from a.14 to 0.39 cm2 and of varying heights (5-rz cm) were used, The elution rate was kept between 0.5 and 0.8 ml/cm” min. r%pcnding on tllc ICI, value, the cluatcs were collected in fractions ranging from 4 to ($4 drops with an autom;Ltic transist<,rized fraction collector, The “dead” volume, t11c volume of the column and the volu~ne per drop of eluate were determined I>y weighing. To dctcrn3ine tlic specific volume, e, of the exchanger in oxalic acid medium, a column of ro ml was packed in a graduntccl tube ant1 wastrel successively with 0.75 Ad osalic acid and water. The resin was extruded, air-dried at so-&“, and finally dried in vacuum in the presence of anhydrone to constant weight. Q w‘as found to bc 3.01. The void fraction i of the column was determined as described by KRAUS ct 137Cs cation. A column distribution coefficient al. 14 front VmUx of the non-aclsorbalh2 IJ of 0.39 was obtained. However, batch experiments with ‘37Cs rev&ccl a ICn value for the Cs+ cation of 0.36, According to the relatmn I
where A R=a$tivity in counts per minute of the standard; As=activity in counts of dry resin used (mg) ; and V =volume per minute of the 4-111’1nliquot; gr =weight of tlic solution. The anion exchanger was treated as described by SPEECI~E~~. The resin was washed 3 tilnes .for I 11 with 0.5 N oxalic acid solution. Each time the colloidal particles were removed together with the washing liquid, and the resin was washed several times with distilled water. The oxalatc form of the resin thus obtained was first air-dried at so-Go”, an d nest dried under vacuum over anltydrone to constant weight. About xoo 111g of dried resin was mised with 25 ml of oxalic acid solution of different ~on~entration, containing the metal ions under investigation. After the resin particles had been removed by filtering, 4 ml of the aqueous phase was pipetted into a counting tube and the activity measured against a standard activity.
AKIOh’-EXCHANGE
XK OXALIC
ACID
MEDIA
For all elements, except chromium, equilibrium in Fig. I. For practical reasons the stirring was carried All: experiments were performed at 25”. The distribution coefficients were determined ciently low that the loading of the resin was less than concentrations were sufficiently low not to exceed the
69
was reached rapidly as shown out overnight for at least 17 11. at metal concentrations suffiI*/*. This means that the metal solubility product of the metal
osalates. HD 104
Lu fItI>O.OBM _M Cu (II) Q07M
?03 7”
(Ill) Q50M Zn (II) 0,0!5M
43Y-%ww,i Agitation Fig.
1.
time
~2ttainmcnt
‘li’lii (hours)
of
equilibrium.
trncevs nnd co2222ti92g tcchniq2res For the experiments, the following tracers were used: n@iYa, 4@Sc, b2Cr, 5*Mn, IrlrQCe-l44~r, 17?Lu, 203Hg. *@Co, @dCu, (f%n, ToAs, *@MO, @@mTc, 124mfn, 137Cs, Most of the tracers were obtained by neutron irradiation of appropriate target materials in the BR-I and BK-2 reactors in Mol, operating at fluxes of 4*x011 and IoLQ n/cm@ set respectively. The tracers 64Mn, e@Na, 137Cs and i44Ce were obtained from U.K.A.E.A. (Amersham). All tracers were of sufficient radiochemical purity to be used directly. Since all of the radioisotopes used were y-emitters. the counting of the samples was performed in a well-type NaI(T1) scintillation counter by integral measurements. Where separations were carried out, the purity of the eluates was checked by means of a 40o-channel y-spectrometer. Radioactive
RESULTS
Arsenic, Batch experiments showed Kn values much smaller than xo over the whole molarity range investigated, The values obtained by column experiments are summarized in Table I. Mangamse. Batch, -experiments showed strong adsorption at x0-3 M oxalic acid, the adsorption decreasing rapidly with increasing molarity, and no appreciable adsorption was found for oxalic acid concentrations higher than 0.x M. For oxalic acid concentrations higher than 0.01 M, the experimental conditions were changed,
And.
Cl&n. Actn, 42 fr968) 67-77
I:. ].)I2 CORTIS,
70
I’. VAN
IXZN
WINKEL,
A.
SPBECKE,
J.
HOSTP
i,s. the ratio of the volume of the oxalic acid solution to the weight of dry resin was reduced as indicated in Table II. The adsorbability of Inan~anese(II) thus found, was checked by column experiments over the entire molarity range investigated. Good agreement was found between the Kn values obtained by both techniques. The results, together with the geometrical column volurncs and the V max values, arc shown in Table III.
__--..__-.--.._.--.-
-_---Oxalic
,_-_ .._._.. __......_____~__
-..-
lit,
acid
.-
_^. -.--
-..-__I_
~~1lc~~~l~Y~~t~ot~ (M) _._ . “___._^_.__._-_-__.. --____
Z\‘n vuitce
.-“_..-.-....-___-----. .._.__^._-.----.-
0.001
1.70
0.100
a.oo_J
I.CJJj
0.300
1*3!5 1.10
O.OLO
x.70
0.750
0.90
0.030
1.45
____.,. _______.___ _.__.__._
_,...___._...__ - .-... . .._-._,.----. .._. ‘
._._.
.
.
.
.
..-
.--.._._-..
-
-e--F
._
-
o.ooogG
25
100
too
o.oorg 0.00‘~8 o.oog6
25 25 25
IO0 100 100
85 44
0.0240
25
100
7
10
250 250 250 250 250
22 ci I.5
o.ool)r 0.0230 0.0450 O.Oy)lO
10
10 10
0.1800
10
_________.-.
Ifn
VALUES
22
1.0 0.2
__._.... _-_ _.---._....--. __... . . . .. ,..-.......-_..- --._._
FOR
Osnlic mid coucortrntiorr
MANGANl%SlZ(tI)
FROM
Collr~rlrr
(n/I)
volrrrnc
COLUMN I’
EXI’ERIMKNTS I’,..
32.6
O.GJ
0.0x0
0.75 0.75
6.35 7.15 6.85
0.025
2.fi5
0.025
2.65
G.09
0.050 0.050 0.100
2.67 0.7L 0.71 0.70 0.70
2.32 0.74 0.29 0.29 0.29
0.200
0.500 -___
Am&
Ckirn.
._..--- _-.--..-.-___.
(nil)
It?,,
vazrrcs
(O&l)
0.002
0.010
--.--_
Act@, 42 (xgG8)
_.--.
(,,,g)
(Id)
-_.-
._
acid ~~~ic~~~~~‘~~~~~~ (M)
Ch~tlic
uctf1tc
67-77
100 *7 19 4.8 4.7 I.4 I.7 0.4 0.4 0.4
_
ANION-EXCHANGE
IS
OXALIC
ACID
hfEDIA
71
Cobalt, mercwy, zinc and copper. A portion (I ml) of the respective tracer solution was added to 25 ml of the different oxalic acid solutions and shaken for at least 17 11together with IOO mg of dry resin. The results obtained from these experiments are summarized in Tables IV and V.
f<~
VALUES
IZOK
COU,\tT(Il)
--___
o.ooog6
‘540
O.OOlf) 0.0048 o.oogG 0.024 0.048
1270 770 420 I 26 41
I;,,
ZINC(II)
ICI, vnlrtcs --_-_-_--_ Ztt(Il) CO( If)
Oxalic acid concet8tratiow (fir) .
TAI3LE
AND
x4400 9700 6340 3610 810 230
I’HOhl
MATCII
ESI’ERIMBNTS
Osnlic acid conce7rIraliotb t&f)
-_----
-..
0.072
‘7
0.09.6 0.1.~” O.lc)O
‘5 13 5
0.240 0.290
4 3
lrOK
hIIZKCUKY(IX)
AND
COPPEK(lI)
FROM
UATCII
_----
Oxalic acid comzeutration (M)
0.0460 0.0690 o.og30 0.1400 o.rgoo
Co(lI)
_.-. . _.-_-.%w(??)
.~_____ 100 54 23 12 9 G
v
VALUES
0.00093 0.0018 0.0040 0.0042 0.0230
I\‘Dvalues
I\m vailtcs Ctr(l1) 33100 2x800 I3800 9.100 3130 1250
790 530 280 140
lLXl’ISRIIIlHNTS
---
.- __..._ ML!(I J) 4990 3990 2890
2080 1000 500 330 2Go
136 87
--
.-.-
Oxalic acid couccntrcrtion (fir)
I<,, valtrrs -----_CU(ll)
0.2300 0.2800 0.3200 0.3700
‘30
--.-._-
ifg(Il)
0.4200
59
57 45 37 -
0.46oo 0.4800 0.7200 0.g400
45 38
-
II0 80
Gr
-
2G
--
rcl
At low oxalic acid concentrations, the Kn values increase in the sequence Co(I1) c H&II) c Zn(I1) c Cu(I1). At 0.02 M, the adsorption functions for zinc(I1) and mercury(I1) intersect. The copper(I1) and mercury(I1) curves approach each other at higher molarity. Consequently, the separation of copper and mercury will not be rapid and efficient, as is desirable in activation analysis. From column experiments, carried out at molarities ranging from 0.075 to 0.75 M oxalic acid, Kn values were obtained in good agreement with those obtained from batch experiments. The results are presented in Table VI. iridium and molybdetium. From batch experiments (Table VII) it was found that indium(II1) shows a strong adsorbability. Though indium(II1) might be removed quantitatively with oxalic acid solution of high molarity from an anion-exchange column, this medium is not suited for practical elutions of this element. The Kn values for molybdenum(V1) were estimated as being higher than xo6 Ajtal. Clha.
Ada,
42 (x968)
67-77
F.
72
RI3 COIUE,
I’.
VAN
DEN
WINKEL,
A. SPEECKE,
J. HOSTE
over the whole molarity range. After agitation for 17 11, the tubes were removed from the agitation bath and allowed to stand for 2 days. This time interval was necessary for either the cstablisl~mcnt of the *@MO-ODmTcequilibrium or the decay of the QQmTcdaughter. After this time, aliquots were pipetted and counted. For the whole concentration range, the activities measured fell within the standard deviation o of the background. By taking 2~ as the upper limit of activity, a minimum Ir’a value of 106 was calculatccl.
____~___.______._
. _ - -._._-
_.l_l_._.
O.wiic
cicid
ICn
. _-.._
.____-_-_.-.-.
-_.-_...__...___
-__-.I
34 II -
o.oG25
0.125 0.150 0.2fio
1.7
0.750
I.4 ___.Lr-_--
---
Il’n ---.
I.
VALUIZS
FOR --
. _.... . . ..- -...--_
_” ___^_.___ _.__-_. * _._ ._-._
30 7.6 4.6
3.9
0.300 0.500
,..____._-.-_--_-._
vnirres
XNDIUM(IIS)
_-__
FRO&l
-
120
-
49 28
2.5 ._ ---_-
-
BATCII .-
.-
22 _...-__ ___l-____-_
l3XDI‘5RlMENTS --._i.__
25 ._.. _.__--_-
--
Osalic cbcirl cowcxtratio?, /Ml -. __ _--.--I o.oog6
I\*!, values
7W50
0.290
2910
0.024
Goooo
0.3&p
I@30
0.048 0.072
@400 4 I go0 o.ogG a0870 o.rqo 11740 O.Iz)O 5750 0,240 3990 __-Ic_-_..-.m__--P-_
Oxnlic mid come~ttvstio~t -/&I)
-*_
ICI, vahtcs _______---*
0.380
r550
0.430
1200
0.480 0.720 O*Q40
.____
930 430 340
C~~~o?~~~~~.I3atch experiments showed that the 1G values increase with increasing stirring time. Even after 144 h no constant values were obtained as shown in Fig. 2. The dotted curve was obtained at 0.75 M oxalic acid and represents the K;, values as a function of time. The full lines result from experiments over the whole molarity SC& with shaking times of 6, x7 and 144 h, In column experiments, freshly prepared oxalic acid solutions of chronliunl(III) were added to small columns of Dowex x-X8 resin. On eiution with the appropriate acid molarity, large amounts (60-80~/~) of chromium(II1) immediately passed through the columns, while the remainder was strongly adsorbed. A plausible explanation of these results may be given by assuming that in the original chromium(II1) solution weakly adsorbed chromium-chloro and chromium-chloro-aqua compleses are present. Upon shaking with oxalic acid solutions, the latter may be converted slowly into strongly adsorbed oxalato complexes, Amal.
Clrittz.A&.
42 (1968) 67-77
ANLON-EXCHANGE
IN OXALIC
ACID
MEDIA
73
Scandium. Results from batch experiments are presented in Table values are given for molarities lower than O.OI~ as the ICI, values are too the specific activity of the 4asc tracer too low for accurate results. Column experiments gave results (Table IX) in good agreement results obtained from batch experiments. Cevizrnt a& Zrttcti~wt. Tl~e results of batch and column experiments in Table S.
,~
VIII. high
No and
with
the
are given
.;::~~~,~~~~~~
lo-’
lo-”
lo-2
IO“ -1 Mol. oxalic acid
0.1
1
10
100
Fib’.
2. Kn
TABLE KD
values
claron~ium(Ifll) as n function of oxalic ncid concentration
for
FOR
SCAWDIU&f(lII)
Oxalic
acid co?tcetttratiotb liV.J ---___..-_-__
KD valrre
o.orgz 0.0384 0.0577
28600
FROM
35x0
0.1923 0.2404
680
DhTCii l%XPERIMIZNTS ---_.-
nnd of time.
_----
Oxalic acid co~lce?t~~~~~#~t (fif) -_----_._. p..“._.-
Ku W&U
0.2885
355
0.4327 0.5709 0.7209 0.9423
118OO Gz20
0.0772
Ifn
time in hours
.: . VIII
VALUE3
TADLIZ
-Agitation
170 IO8
80 50
460 IS
VALUES
Oxulic acid f lV1)
FOR
SCANDIUnl~IlI)
A nlotcnt adsorbed
0.200
0.011
o.Goo
0.060
0,QOO
0.016
PROM
of SC (pg)
iOtUhlN
HXPBRIMENTS
Coitbntit fcm3) 0.483 0.483 a.483
volunte
KD value
079
*
From Fig. 3, a #S-value (ratio of the two KD values) of 8 was calculated for an oxalic acid concentration of 0.5 M. From Uris it may be concluded that cerium and lutetium can be separated in this medium (see below). Furthermore, it may be expected that the rare earths can be separated into groups each including three successive elements. Anicl,
Cltim.
Acta,
42 (1968)
67-77
74 I<,,
VALUlCS
x;oic
caRxunr(rlx)
AND
LUTIZTIUhI(IlI)
1:ROnl
11ATCII
AND
COLUMN
EXl’ERInlIINTS
..-..--..-
.-_-_~--.-.
mid
O.rulic
_.---.-_--_--.-A---
Lll(lIl)
CC(lll)
_.._^..__.._ --.-
--
ucid co~~corlrirlion Osdic
K,, vul11es
(hi)
.- .- -. .
11-n
1111l11cs
.-_--_-
Ce(lJ1)
-
Lll(IIl)
-
_...-
.-. -.
/~UICll
0*000c)(J
ZO~JOO
-
O.OOlC,
I5fKJO 12goo 9230 7110 I x.p 53’2 3HCJ
-.. _-_ _.._. ._5 2 5”” I RHO0 07.p
o.oop
0.005H 0.0077 0.01gz 0.0:QL#
0.057Cl
185 5” 29
(J
‘I
‘3 II 10 - ._
Cdlt~,lll o.oc,o
-
,105 36 _-
0.200 0.300
O.‘lSO
_. . . . __.___- .
_-. .-. ..__-.._..._ -...
_-
I2 -
0.500
558 zoo
5.6
0.750
__ __ _.. .
04 -+8
..
7
Volume of eluate tractions ot 0.72
Pig. 3. Kn cxpcrinwnts.
values
Fig. 4. Scpnmtion cm’J.
ns a 111nction
of oxalic
of nx~~q~ncsc(lI)
acid
concentration.
front coppcr(I1).
Column
l coluinn height
ml
cxpcrirncnts,
.I..+ cm,
cross-section
0
batch
0.136
Separatiom When ion-exchange separations are applied to practical determinations of trace elements in neutron activation analysis, it is desirable that: in) the element under investigation should be recovered quantitatively in the eluate; (b) the volume of eluate should be small (20 ml) so that a high counting efficiency can be achieved; (c) the cross-contamination of the eluted bands must. be negligible: arid (d) a short Amd.
Chim.
Rcln,
42
(xgG8)
67-77
ANION-EXCHAN&
IS
OXALIC
ACID
MEDIA
75
separation time is required for the determination of elements giving rise to shortliving isotopes. In the separation of rnanganese(II) from coppcr(l1) (Fig. 41, the yield was roe% for both elements, while the elution volumes were 5 ml for manganese(I1) and about x5 ml for copper(I1). The elution of copper(I1) may also be performed with a mixture of 0.75 M oxalic acid and 5 O/ ,,, thiourea; under these conditions the elution band of copper( I I) becomes sharper. Checking both eluates by means of the multichannel analyser revealed absolute purity of both fractions. The separation was accomplished in about 2.5 11. In Fig. 5, the quantitative separation of sodium, manganese and zinc is represented. The volume in which the tracers were originally present, was 300 ~1, Soclium was eluted with 6 ml of 0.01 M oxalic acid. The volume in which the total 5JMn activity was present amounted to about I,3 ml of 0.150 M oxalic acid. Finally, zinc was recovered quantitatively in 15 ml of 0.75 M oxalic acid. The total separation was carried out in about 3 11 but the manganese fraction was recovered in about 1.5 h which represents less than one half-life of the WMn isotope obtainecl by the (n,?) reaction, on irradiating the only natural isotope of manganese.
volume of eluate
lractions
ot wzrnl
Voktme
Fig. 5. Separation of sodium(I), mangancsc(Il) height I x.0 cm, cross-section 0.15 cm=. Fig. G. Separation of ~~s(Ill)[+~u(l)], pretreated with 0.005 ICI oxalic acid. elutcd. Column iwight 12.9 cm, diameter
and zinc(I1).
effluent
l total pcrccntagc
in ml clutcd. Column
?dn(Ii), Co(IX), Zn(i1) nncl Cu(~I)[~~I~(iI)]. pcrccntagc clutccl per fraction; ---- total 0.704 cm.
Column pcrcentagc
The separation of five elements, As(III), Mn(II), Co(H), Zn(Il) and Cu(II), in pure oxalic acid is shown in Fig, 6. From the adsorption curves shown in Fig. 3, it is obvious that sodium might be eluted together with arsenic(II1) in the first fraction, while mercury(I1) wilt he present in the copper(I1) eluate. The experimental conditions are summarized in Table XI. The geometrical column volume for these experiments was equal to 5.02 ml. The resin was pretreated with 0.005 M oxalic acid. The tracers were added in fractions of IOO ~1 of 0.005 M acid and adsorbed at a rate of I drop per min (0.0505 ml/min). The elution was performed at a flow rate of 0.30 ml/min ( =0.77 ml/min ems). The column sizes are critical for the separation of manganese(I1) from dobalt(I1). For practical purposes (determination of short-lived isotopes by short irradiaAunt. CIIiltt. Ada, qa (rg68) 67-77
F. DE
76
COHTT:,
I’. VAN
DEN
WINKEL,
A.
SPEECKB,
J. HOSTE
tion at hi& neutron fluxes), the clution of cobalt(I1) may be omitted, while thiourea may be added to the 0.75 M oxalic acid solution after zinc(I1) has been eluted. Mercury and copper may the,1 be counted by simple pulse-height discrimination. ‘For the separation of ccrium(II1) andlutetium(III), amixture of these elements was adsorbed in 0.50 M oxalic acid on a column of o.92 ml; ceriurn(II1) was eluted first with 20 ml of 0.50 M oxalic acid, whereaftcr lutctium(II1) was removed with about the same volume of 0.75 M oxalic acid. The elution curves are shown in Fig .7.
ISXl’XI.RILIBNTAL CONDITIONS FOR T1115 SISI’ARATION WIT11 OXALIC ACID AS ELUANT _.__~.___ . . ...__ .__. -___. --_... l~Ll?r?rl*~lt
Cwricr
tcrrrorrut
O.viblic
-.-.--
-------
7
Mll(II)
Co(ll) Zll(Il) ClI(II)
55
Fume
eluted
(M/
(fraction
I’olurrrc rccovcvy ._--.
._----
hIll(
L I),
_._.-_____. fov
cO(l
t),
ih(I
1)
AND
cU(lI)
__-_ ._...__-___
q~~icnlilulivc
(WI/ ..___
..._--.--
8.1
0.10
13.0
0.10
40.5 17.8
0.75 0.75
20
I),
_. ._. _...._
0.10
2
h(lt
mid
cowxwthwlimt
(PSl --_-_-AY(rII)
OF
40.5
of 7.35ml)
Fig. 7. Scpnratiou of ccrium(ll1)
from lutctium(II1).
Column volume 0.92 cni3.
Grateful acknowledgement is made to the “Nationaal Fonds voor Wetenschappelijk Onderzoek” and to the “Interuniversitair Instituut voor Kcrnwetenschappen” for financial support. Thanks are also due to Mr. L. MEES for technical assistance. SUMMARY
The distribution coefficients were determined for twelve elements, namely As(III), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), Mn(II), H&II), Mo(VI), Sc(II1) and Zn(II), on a strong base anion exchanger in pure oxalic acid solutions. The KD curves are given. A scheme was developed for the chrornatographic separation of five elements, namely As(III), Mn(II), Co(II), Zn(I1) and Cu(I1). Ce(II1) can be separated from Lu(II1). Aural.
Chht.
Acta,
42
(IgGS)
67-77
AXION-EXCHAEGE
Ih’
OXALIC
ACID
77
MEI)lA
On a d&.crminc5 les coefficients de partage pour 12 dlhents, notamment As(III), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), Mn(II), Hg(II), Mo(VI), Sc(II1) et %n(II), sur un &liangcur d’anions fortement basique, en milieu acide oxaliclue pur. Lcs courbcs Kn sont dorm&s. Un schha est proposal pour la s6paration chrornatogralhiquc de cinq 4l&ncnts, notamment As(III), Mh(II), Co(II), %n(II) et Cu(I1). 1.42c&ium(IIt) pcut dtrc s4parh d’avec le lut&ium(III).
Die Vertcilungskoeffizientcn folgcnder I,0 Elernentc ;Ln cinem &ark basischcn Anionenaustauscher in reinen Oxalsliure-L6sungcn wurden bcstimmt : A~(11 I), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), lMn(II), Hg(II), IMo(VI), Sc(II1) und Zn( II). Die KwlCurven wcrden angegeben. Es wurde ein Schema zur chromatograplrischen Trennung von As(III), Mn(II), Co(II), %n(It) und Cu(I1) entwickelt. Cc(II1) kann von Lu(II1) getrcnnt werden.
3 J. 1’. CLARIS..-I tcnl. Chow., 32 (xc)c,o) 5x0. .*I rtiotr E.uc/ta~rgc Sttrdics irt Fltosj3lroric J. PASCUAL AND h. :\. 1)ELtlCCIlI. 4 13. c. 1:RKILlNG. Acid Solutions, I~cscnrcl~ nnd Dcvcloprncnt, ‘Tcchn. I<+. USNIIDl,-‘L’R-231-NS oSr-oar. ..Jcta Chotr. Scntrd., rg (rgG5) G70. 5 I.. I>ANIKLSON, C> J. 1’. FARIS, Pitts6trrglt Coitf. on Atrrcl. Cltmt. curd Applied Sfic.clroscopy, Feb. x962. 7 I’. NELSON, I<. ;\I. I
L.
10 ;\.
I)ANII
Tnutuul I I I<. h. 12
E.
in cliloro-osalttut
C/rem.
I-IOSTK.
Stand.,
milieu
1859.
2
(1959) 33’; met .4rtiottttifwissr~lanr. &I. Lq. %~X?YI;ItS, J.
I-iORNE, I<. ti. kfOLhl AND I<. TIIOMI’ICINS AND s. \v. hlAYEI<; TRBMILLON, LES Sd#mrafions par
r3 1% 19%.
rg (x965)
?‘Uhlfr4,
f.
Its
/fttZ.
CilC:,N.
Rbsirrcs
r\. SPE~CKE, Sclteidit~g WLU Niobium Ihctorantstlwsis, C;hcnt, 1959. P/lyS. SOC.,
C/MWl., 6s)
Ecltattgctrses
61
(1957)
cn
1661.
(X9.)7) 2855). d’lous, Gauthicrs-Villnrs,
Paris,
Proc. [..-I. E./l. Co,?/. ott Radioisotopes i,t the I<. A. ICRAUS, M. 0. 1’IIlLIPS AND 1;. NELSON, Vol. 3, I.A.E.A., Vicnnn, 1962, p, 387. Whys. Sciemxs arrd Itrdttstry. z9G0, Copotlrrcgett, x5 I?. NELSOS, T. ~IURASE AND 1;. 11. I
_4md. C/tint.
.4&a,
.+z (1gG8)
67-77
DISTRIBUTION ACiD MEDIUM
COEFFICIENTS ON A STRONG
67
FOR TWELVE ANION-EXCHANGE
ELEMENTS RESIN
IN
OXALIC
Systematic surveys of the behaviour of elements on a strong base anionphosphoric4, exchange resin have been reported for hydrochloric 1, nitri&,hydrofluoric”, sulfuric acid”, and hydrochloric-hydrofluoricap7, nitric-hydrofluoric*vo and sulfurichydrofluoric acid mixtures 0. The adsorption characteristics in the above-mentioned mineral acids are now always applicable to separation techniques,
OF
THE
DISTRII3UTLO3i
COXSTASTS
The adsorbabilities are expressed as weight distribution coefficients, ICI, (axn~~unt per Q dry resin~amount per ml of solution). They can be determined by batch’” or column methods. When column techniques are used, either the clution chromatographic or the break-through method 13914can be applied. Furthermore, for the determination of large distribution coefficients, use can be made of the preloaded column techniquei4ei5. In this study, small Kn values were calculated from the corrected peak elution volume, I/moX. i.e. the volume of eluant required to elute the maximum of the elution band, by the following expression 1s~12 e*(Vm,,/V-i)=K~
(1)
where V =total volume of the column (height x cross-sectional area), ,g=specific volume of the exchanger, and i =void fraction of the column. Small aliquots of so-IOO p1 of the tracer solution containing the ion under T
**
Research associate of the N.F.W.0, Research associate of the I. I. K.W. Arrat.
Claim.
A&r.
42 (rgG8) 67-77
G8
I:. I>ECORTJ?,P.
VAN
DEN
WINKEL,
A.
SPEECKB,
J.
HOSTE
investigation, were adsorl~ecl rJn ttle top of the column, after the resin had been pretreated with the appropriate oxalic acid solution. Columns of cross-sections ranging from a.14 to 0.39 cm2 and of varying heights (5-rz cm) were used, The elution rate was kept between 0.5 and 0.8 ml/cm” min. r%pcnding on tllc ICI, value, the cluatcs were collected in fractions ranging from 4 to ($4 drops with an autom;Ltic transist<,rized fraction collector, The “dead” volume, t11c volume of the column and the volu~ne per drop of eluate were determined I>y weighing. To dctcrn3ine tlic specific volume, e, of the exchanger in oxalic acid medium, a column of ro ml was packed in a graduntccl tube ant1 wastrel successively with 0.75 Ad osalic acid and water. The resin was extruded, air-dried at so-&“, and finally dried in vacuum in the presence of anhydrone to constant weight. Q w‘as found to bc 3.01. The void fraction i of the column was determined as described by KRAUS ct 137Cs cation. A column distribution coefficient al. 14 front VmUx of the non-aclsorbalh2 IJ of 0.39 was obtained. However, batch experiments with ‘37Cs rev&ccl a ICn value for the Cs+ cation of 0.36, According to the relatmn I
where A R=a$tivity in counts per minute of the standard; As=activity in counts of dry resin used (mg) ; and V =volume per minute of the 4-111’1nliquot; gr =weight of tlic solution. The anion exchanger was treated as described by SPEECI~E~~. The resin was washed 3 tilnes .for I 11 with 0.5 N oxalic acid solution. Each time the colloidal particles were removed together with the washing liquid, and the resin was washed several times with distilled water. The oxalatc form of the resin thus obtained was first air-dried at so-Go”, an d nest dried under vacuum over anltydrone to constant weight. About xoo 111g of dried resin was mised with 25 ml of oxalic acid solution of different ~on~entration, containing the metal ions under investigation. After the resin particles had been removed by filtering, 4 ml of the aqueous phase was pipetted into a counting tube and the activity measured against a standard activity.
AKIOh’-EXCHANGE
XK OXALIC
ACID
MEDIA
For all elements, except chromium, equilibrium in Fig. I. For practical reasons the stirring was carried All: experiments were performed at 25”. The distribution coefficients were determined ciently low that the loading of the resin was less than concentrations were sufficiently low not to exceed the
69
was reached rapidly as shown out overnight for at least 17 11. at metal concentrations suffiI*/*. This means that the metal solubility product of the metal
osalates. HD 104
Lu fItI>O.OBM _M Cu (II) Q07M
?03 7”
(Ill) Q50M Zn (II) 0,0!5M
43Y-%ww,i Agitation Fig.
1.
time
~2ttainmcnt
‘li’lii (hours)
of
equilibrium.
trncevs nnd co2222ti92g tcchniq2res For the experiments, the following tracers were used: n@iYa, 4@Sc, b2Cr, 5*Mn, IrlrQCe-l44~r, 17?Lu, 203Hg. *@Co, @dCu, (f%n, ToAs, *@MO, @@mTc, 124mfn, 137Cs, Most of the tracers were obtained by neutron irradiation of appropriate target materials in the BR-I and BK-2 reactors in Mol, operating at fluxes of 4*x011 and IoLQ n/cm@ set respectively. The tracers 64Mn, e@Na, 137Cs and i44Ce were obtained from U.K.A.E.A. (Amersham). All tracers were of sufficient radiochemical purity to be used directly. Since all of the radioisotopes used were y-emitters. the counting of the samples was performed in a well-type NaI(T1) scintillation counter by integral measurements. Where separations were carried out, the purity of the eluates was checked by means of a 40o-channel y-spectrometer. Radioactive
RESULTS
Arsenic, Batch experiments showed Kn values much smaller than xo over the whole molarity range investigated, The values obtained by column experiments are summarized in Table I. Mangamse. Batch, -experiments showed strong adsorption at x0-3 M oxalic acid, the adsorption decreasing rapidly with increasing molarity, and no appreciable adsorption was found for oxalic acid concentrations higher than 0.x M. For oxalic acid concentrations higher than 0.01 M, the experimental conditions were changed,
And.
Cl&n. Actn, 42 fr968) 67-77
I:. ].)I2 CORTIS,
70
I’. VAN
IXZN
WINKEL,
A.
SPBECKE,
J.
HOSTP
i,s. the ratio of the volume of the oxalic acid solution to the weight of dry resin was reduced as indicated in Table II. The adsorbability of Inan~anese(II) thus found, was checked by column experiments over the entire molarity range investigated. Good agreement was found between the Kn values obtained by both techniques. The results, together with the geometrical column volurncs and the V max values, arc shown in Table III.
__--..__-.--.._.--.-
-_---Oxalic
,_-_ .._._.. __......_____~__
-..-
lit,
acid
.-
_^. -.--
-..-__I_
~~1lc~~~l~Y~~t~ot~ (M) _._ . “___._^_.__._-_-__.. --____
Z\‘n vuitce
.-“_..-.-....-___-----. .._.__^._-.----.-
0.001
1.70
0.100
a.oo_J
I.CJJj
0.300
1*3!5 1.10
O.OLO
x.70
0.750
0.90
0.030
1.45
____.,. _______.___ _.__.__._
_,...___._...__ - .-... . .._-._,.----. .._. ‘
._._.
.
.
.
.
..-
.--.._._-..
-
-e--F
._
-
o.ooogG
25
100
too
o.oorg 0.00‘~8 o.oog6
25 25 25
IO0 100 100
85 44
0.0240
25
100
7
10
250 250 250 250 250
22 ci I.5
o.ool)r 0.0230 0.0450 O.Oy)lO
10
10 10
0.1800
10
_________.-.
Ifn
VALUES
22
1.0 0.2
__._.... _-_ _.---._....--. __... . . . .. ,..-.......-_..- --._._
FOR
Osnlic mid coucortrntiorr
MANGANl%SlZ(tI)
FROM
Collr~rlrr
(n/I)
volrrrnc
COLUMN I’
EXI’ERIMKNTS I’,..
32.6
O.GJ
0.0x0
0.75 0.75
6.35 7.15 6.85
0.025
2.fi5
0.025
2.65
G.09
0.050 0.050 0.100
2.67 0.7L 0.71 0.70 0.70
2.32 0.74 0.29 0.29 0.29
0.200
0.500 -___
Am&
Ckirn.
._..--- _-.--..-.-___.
(nil)
It?,,
vazrrcs
(O&l)
0.002
0.010
--.--_
Act@, 42 (xgG8)
_.--.
(,,,g)
(Id)
-_.-
._
acid ~~~ic~~~~~‘~~~~~~ (M)
Ch~tlic
uctf1tc
67-77
100 *7 19 4.8 4.7 I.4 I.7 0.4 0.4 0.4
_
ANION-EXCHANGE
IS
OXALIC
ACID
hfEDIA
71
Cobalt, mercwy, zinc and copper. A portion (I ml) of the respective tracer solution was added to 25 ml of the different oxalic acid solutions and shaken for at least 17 11together with IOO mg of dry resin. The results obtained from these experiments are summarized in Tables IV and V.
f<~
VALUES
IZOK
COU,\tT(Il)
--___
o.ooog6
‘540
O.OOlf) 0.0048 o.oogG 0.024 0.048
1270 770 420 I 26 41
I;,,
ZINC(II)
ICI, vnlrtcs --_-_-_--_ Ztt(Il) CO( If)
Oxalic acid concet8tratiow (fir) .
TAI3LE
AND
x4400 9700 6340 3610 810 230
I’HOhl
MATCII
ESI’ERIMBNTS
Osnlic acid conce7rIraliotb t&f)
-_----
-..
0.072
‘7
0.09.6 0.1.~” O.lc)O
‘5 13 5
0.240 0.290
4 3
lrOK
hIIZKCUKY(IX)
AND
COPPEK(lI)
FROM
UATCII
_----
Oxalic acid comzeutration (M)
0.0460 0.0690 o.og30 0.1400 o.rgoo
Co(lI)
_.-. . _.-_-.%w(??)
.~_____ 100 54 23 12 9 G
v
VALUES
0.00093 0.0018 0.0040 0.0042 0.0230
I\‘Dvalues
I\m vailtcs Ctr(l1) 33100 2x800 I3800 9.100 3130 1250
790 530 280 140
lLXl’ISRIIIlHNTS
---
.- __..._ ML!(I J) 4990 3990 2890
2080 1000 500 330 2Go
136 87
--
.-.-
Oxalic acid couccntrcrtion (fir)
I<,, valtrrs -----_CU(ll)
0.2300 0.2800 0.3200 0.3700
‘30
--.-._-
ifg(Il)
0.4200
59
57 45 37 -
0.46oo 0.4800 0.7200 0.g400
45 38
-
II0 80
Gr
-
2G
--
rcl
At low oxalic acid concentrations, the Kn values increase in the sequence Co(I1) c H&II) c Zn(I1) c Cu(I1). At 0.02 M, the adsorption functions for zinc(I1) and mercury(I1) intersect. The copper(I1) and mercury(I1) curves approach each other at higher molarity. Consequently, the separation of copper and mercury will not be rapid and efficient, as is desirable in activation analysis. From column experiments, carried out at molarities ranging from 0.075 to 0.75 M oxalic acid, Kn values were obtained in good agreement with those obtained from batch experiments. The results are presented in Table VI. iridium and molybdetium. From batch experiments (Table VII) it was found that indium(II1) shows a strong adsorbability. Though indium(II1) might be removed quantitatively with oxalic acid solution of high molarity from an anion-exchange column, this medium is not suited for practical elutions of this element. The Kn values for molybdenum(V1) were estimated as being higher than xo6 Ajtal. Clha.
Ada,
42 (x968)
67-77
F.
72
RI3 COIUE,
I’.
VAN
DEN
WINKEL,
A. SPEECKE,
J. HOSTE
over the whole molarity range. After agitation for 17 11, the tubes were removed from the agitation bath and allowed to stand for 2 days. This time interval was necessary for either the cstablisl~mcnt of the *@MO-ODmTcequilibrium or the decay of the QQmTcdaughter. After this time, aliquots were pipetted and counted. For the whole concentration range, the activities measured fell within the standard deviation o of the background. By taking 2~ as the upper limit of activity, a minimum Ir’a value of 106 was calculatccl.
____~___.______._
. _ - -._._-
_.l_l_._.
O.wiic
cicid
ICn
. _-.._
.____-_-_.-.-.
-_.-_...__...___
-__-.I
34 II -
o.oG25
0.125 0.150 0.2fio
1.7
0.750
I.4 ___.Lr-_--
---
Il’n ---.
I.
VALUIZS
FOR --
. _.... . . ..- -...--_
_” ___^_.___ _.__-_. * _._ ._-._
30 7.6 4.6
3.9
0.300 0.500
,..____._-.-_--_-._
vnirres
XNDIUM(IIS)
_-__
FRO&l
-
120
-
49 28
2.5 ._ ---_-
-
BATCII .-
.-
22 _...-__ ___l-____-_
l3XDI‘5RlMENTS --._i.__
25 ._.. _.__--_-
--
Osalic cbcirl cowcxtratio?, /Ml -. __ _--.--I o.oog6
I\*!, values
7W50
0.290
2910
0.024
Goooo
0.3&p
I@30
0.048 0.072
@400 4 I go0 o.ogG a0870 o.rqo 11740 O.Iz)O 5750 0,240 3990 __-Ic_-_..-.m__--P-_
Oxnlic mid come~ttvstio~t -/&I)
-*_
ICI, vahtcs _______---*
0.380
r550
0.430
1200
0.480 0.720 O*Q40
.____
930 430 340
C~~~o?~~~~~.I3atch experiments showed that the 1G values increase with increasing stirring time. Even after 144 h no constant values were obtained as shown in Fig. 2. The dotted curve was obtained at 0.75 M oxalic acid and represents the K;, values as a function of time. The full lines result from experiments over the whole molarity SC& with shaking times of 6, x7 and 144 h, In column experiments, freshly prepared oxalic acid solutions of chronliunl(III) were added to small columns of Dowex x-X8 resin. On eiution with the appropriate acid molarity, large amounts (60-80~/~) of chromium(II1) immediately passed through the columns, while the remainder was strongly adsorbed. A plausible explanation of these results may be given by assuming that in the original chromium(II1) solution weakly adsorbed chromium-chloro and chromium-chloro-aqua compleses are present. Upon shaking with oxalic acid solutions, the latter may be converted slowly into strongly adsorbed oxalato complexes, Amal.
Clrittz.A&.
42 (1968) 67-77
ANLON-EXCHANGE
IN OXALIC
ACID
MEDIA
73
Scandium. Results from batch experiments are presented in Table values are given for molarities lower than O.OI~ as the ICI, values are too the specific activity of the 4asc tracer too low for accurate results. Column experiments gave results (Table IX) in good agreement results obtained from batch experiments. Cevizrnt a& Zrttcti~wt. Tl~e results of batch and column experiments in Table S.
,~
VIII. high
No and
with
the
are given
.;::~~~,~~~~~~
lo-’
lo-”
lo-2
IO“ -1 Mol. oxalic acid
0.1
1
10
100
Fib’.
2. Kn
TABLE KD
values
claron~ium(Ifll) as n function of oxalic ncid concentration
for
FOR
SCAWDIU&f(lII)
Oxalic
acid co?tcetttratiotb liV.J ---___..-_-__
KD valrre
o.orgz 0.0384 0.0577
28600
FROM
35x0
0.1923 0.2404
680
DhTCii l%XPERIMIZNTS ---_.-
nnd of time.
_----
Oxalic acid co~lce?t~~~~~#~t (fif) -_----_._. p..“._.-
Ku W&U
0.2885
355
0.4327 0.5709 0.7209 0.9423
118OO Gz20
0.0772
Ifn
time in hours
.: . VIII
VALUE3
TADLIZ
-Agitation
170 IO8
80 50
460 IS
VALUES
Oxulic acid f lV1)
FOR
SCANDIUnl~IlI)
A nlotcnt adsorbed
0.200
0.011
o.Goo
0.060
0,QOO
0.016
PROM
of SC (pg)
iOtUhlN
HXPBRIMENTS
Coitbntit fcm3) 0.483 0.483 a.483
volunte
KD value
079
*
From Fig. 3, a #S-value (ratio of the two KD values) of 8 was calculated for an oxalic acid concentration of 0.5 M. From Uris it may be concluded that cerium and lutetium can be separated in this medium (see below). Furthermore, it may be expected that the rare earths can be separated into groups each including three successive elements. Anicl,
Cltim.
Acta,
42 (1968)
67-77
74 I<,,
VALUlCS
x;oic
caRxunr(rlx)
AND
LUTIZTIUhI(IlI)
1:ROnl
11ATCII
AND
COLUMN
EXl’ERInlIINTS
..-..--..-
.-_-_~--.-.
mid
O.rulic
_.---.-_--_--.-A---
Lll(lIl)
CC(lll)
_.._^..__.._ --.-
--
ucid co~~corlrirlion Osdic
K,, vul11es
(hi)
.- .- -. .
11-n
1111l11cs
.-_--_-
Ce(lJ1)
-
Lll(IIl)
-
_...-
.-. -.
/~UICll
0*000c)(J
ZO~JOO
-
O.OOlC,
I5fKJO 12goo 9230 7110 I x.p 53’2 3HCJ
-.. _-_ _.._. ._5 2 5”” I RHO0 07.p
o.oop
0.005H 0.0077 0.01gz 0.0:QL#
0.057Cl
185 5” 29
(J
‘I
‘3 II 10 - ._
Cdlt~,lll o.oc,o
-
,105 36 _-
0.200 0.300
O.‘lSO
_. . . . __.___- .
_-. .-. ..__-.._..._ -...
_-
I2 -
0.500
558 zoo
5.6
0.750
__ __ _.. .
04 -+8
..
7
Volume of eluate tractions ot 0.72
Pig. 3. Kn cxpcrinwnts.
values
Fig. 4. Scpnmtion cm’J.
ns a 111nction
of oxalic
of nx~~q~ncsc(lI)
acid
concentration.
front coppcr(I1).
Column
l coluinn height
ml
cxpcrirncnts,
.I..+ cm,
cross-section
0
batch
0.136
Separatiom When ion-exchange separations are applied to practical determinations of trace elements in neutron activation analysis, it is desirable that: in) the element under investigation should be recovered quantitatively in the eluate; (b) the volume of eluate should be small (20 ml) so that a high counting efficiency can be achieved; (c) the cross-contamination of the eluted bands must. be negligible: arid (d) a short Amd.
Chim.
Rcln,
42
(xgG8)
67-77
ANION-EXCHAN&
IS
OXALIC
ACID
MEDIA
75
separation time is required for the determination of elements giving rise to shortliving isotopes. In the separation of rnanganese(II) from coppcr(l1) (Fig. 41, the yield was roe% for both elements, while the elution volumes were 5 ml for manganese(I1) and about x5 ml for copper(I1). The elution of copper(I1) may also be performed with a mixture of 0.75 M oxalic acid and 5 O/ ,,, thiourea; under these conditions the elution band of copper( I I) becomes sharper. Checking both eluates by means of the multichannel analyser revealed absolute purity of both fractions. The separation was accomplished in about 2.5 11. In Fig. 5, the quantitative separation of sodium, manganese and zinc is represented. The volume in which the tracers were originally present, was 300 ~1, Soclium was eluted with 6 ml of 0.01 M oxalic acid. The volume in which the total 5JMn activity was present amounted to about I,3 ml of 0.150 M oxalic acid. Finally, zinc was recovered quantitatively in 15 ml of 0.75 M oxalic acid. The total separation was carried out in about 3 11 but the manganese fraction was recovered in about 1.5 h which represents less than one half-life of the WMn isotope obtainecl by the (n,?) reaction, on irradiating the only natural isotope of manganese.
volume of eluate
lractions
ot wzrnl
Voktme
Fig. 5. Separation of sodium(I), mangancsc(Il) height I x.0 cm, cross-section 0.15 cm=. Fig. G. Separation of ~~s(Ill)[+~u(l)], pretreated with 0.005 ICI oxalic acid. elutcd. Column iwight 12.9 cm, diameter
and zinc(I1).
effluent
l total pcrccntagc
in ml clutcd. Column
?dn(Ii), Co(IX), Zn(i1) nncl Cu(~I)[~~I~(iI)]. pcrccntagc clutccl per fraction; ---- total 0.704 cm.
Column pcrcentagc
The separation of five elements, As(III), Mn(II), Co(H), Zn(Il) and Cu(II), in pure oxalic acid is shown in Fig, 6. From the adsorption curves shown in Fig. 3, it is obvious that sodium might be eluted together with arsenic(II1) in the first fraction, while mercury(I1) wilt he present in the copper(I1) eluate. The experimental conditions are summarized in Table XI. The geometrical column volume for these experiments was equal to 5.02 ml. The resin was pretreated with 0.005 M oxalic acid. The tracers were added in fractions of IOO ~1 of 0.005 M acid and adsorbed at a rate of I drop per min (0.0505 ml/min). The elution was performed at a flow rate of 0.30 ml/min ( =0.77 ml/min ems). The column sizes are critical for the separation of manganese(I1) from dobalt(I1). For practical purposes (determination of short-lived isotopes by short irradiaAunt. CIIiltt. Ada, qa (rg68) 67-77
F. DE
76
COHTT:,
I’. VAN
DEN
WINKEL,
A.
SPEECKB,
J. HOSTE
tion at hi& neutron fluxes), the clution of cobalt(I1) may be omitted, while thiourea may be added to the 0.75 M oxalic acid solution after zinc(I1) has been eluted. Mercury and copper may the,1 be counted by simple pulse-height discrimination. ‘For the separation of ccrium(II1) andlutetium(III), amixture of these elements was adsorbed in 0.50 M oxalic acid on a column of o.92 ml; ceriurn(II1) was eluted first with 20 ml of 0.50 M oxalic acid, whereaftcr lutctium(II1) was removed with about the same volume of 0.75 M oxalic acid. The elution curves are shown in Fig .7.
ISXl’XI.RILIBNTAL CONDITIONS FOR T1115 SISI’ARATION WIT11 OXALIC ACID AS ELUANT _.__~.___ . . ...__ .__. -___. --_... l~Ll?r?rl*~lt
Cwricr
tcrrrorrut
O.viblic
-.-.--
-------
7
Mll(II)
Co(ll) Zll(Il) ClI(II)
55
Fume
eluted
(M/
(fraction
I’olurrrc rccovcvy ._--.
._----
hIll(
L I),
_._.-_____. fov
cO(l
t),
ih(I
1)
AND
cU(lI)
__-_ ._...__-___
q~~icnlilulivc
(WI/ ..___
..._--.--
8.1
0.10
13.0
0.10
40.5 17.8
0.75 0.75
20
I),
_. ._. _...._
0.10
2
h(lt
mid
cowxwthwlimt
(PSl --_-_-AY(rII)
OF
40.5
of 7.35ml)
Fig. 7. Scpnratiou of ccrium(ll1)
from lutctium(II1).
Column volume 0.92 cni3.
Grateful acknowledgement is made to the “Nationaal Fonds voor Wetenschappelijk Onderzoek” and to the “Interuniversitair Instituut voor Kcrnwetenschappen” for financial support. Thanks are also due to Mr. L. MEES for technical assistance. SUMMARY
The distribution coefficients were determined for twelve elements, namely As(III), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), Mn(II), H&II), Mo(VI), Sc(II1) and Zn(II), on a strong base anion exchanger in pure oxalic acid solutions. The KD curves are given. A scheme was developed for the chrornatographic separation of five elements, namely As(III), Mn(II), Co(II), Zn(I1) and Cu(I1). Ce(II1) can be separated from Lu(II1). Aural.
Chht.
Acta,
42
(IgGS)
67-77
AXION-EXCHAEGE
Ih’
OXALIC
ACID
77
MEI)lA
On a d&.crminc5 les coefficients de partage pour 12 dlhents, notamment As(III), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), Mn(II), Hg(II), Mo(VI), Sc(II1) et %n(II), sur un &liangcur d’anions fortement basique, en milieu acide oxaliclue pur. Lcs courbcs Kn sont dorm&s. Un schha est proposal pour la s6paration chrornatogralhiquc de cinq 4l&ncnts, notamment As(III), Mh(II), Co(II), %n(II) et Cu(I1). 1.42c&ium(IIt) pcut dtrc s4parh d’avec le lut&ium(III).
Die Vertcilungskoeffizientcn folgcnder I,0 Elernentc ;Ln cinem &ark basischcn Anionenaustauscher in reinen Oxalsliure-L6sungcn wurden bcstimmt : A~(11 I), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), lMn(II), Hg(II), IMo(VI), Sc(II1) und Zn( II). Die KwlCurven wcrden angegeben. Es wurde ein Schema zur chromatograplrischen Trennung von As(III), Mn(II), Co(II), %n(It) und Cu(I1) entwickelt. Cc(II1) kann von Lu(II1) getrcnnt werden.
3 J. 1’. CLARIS..-I tcnl. Chow., 32 (xc)c,o) 5x0. .*I rtiotr E.uc/ta~rgc Sttrdics irt Fltosj3lroric J. PASCUAL AND h. :\. 1)ELtlCCIlI. 4 13. c. 1:RKILlNG. Acid Solutions, I~cscnrcl~ nnd Dcvcloprncnt, ‘Tcchn. I<+. USNIIDl,-‘L’R-231-NS oSr-oar. ..Jcta Chotr. Scntrd., rg (rgG5) G70. 5 I.. I>ANIKLSON, C> J. 1’. FARIS, Pitts6trrglt Coitf. on Atrrcl. Cltmt. curd Applied Sfic.clroscopy, Feb. x962. 7 I’. NELSON, I<. ;\I. I
L.
10 ;\.
I)ANII
Tnutuul I I I<. h. 12
E.
in cliloro-osalttut
C/rem.
I-IOSTK.
Stand.,
milieu
1859.
2
(1959) 33’; met .4rtiottttifwissr~lanr. &I. Lq. %~X?YI;ItS, J.
I-iORNE, I<. ti. kfOLhl AND I<. TIIOMI’ICINS AND s. \v. hlAYEI<; TRBMILLON, LES Sd#mrafions par
r3 1% 19%.
rg (x965)
?‘Uhlfr4,
f.
Its
/fttZ.
CilC:,N.
Rbsirrcs
r\. SPE~CKE, Sclteidit~g WLU Niobium Ihctorantstlwsis, C;hcnt, 1959. P/lyS. SOC.,
C/MWl., 6s)
Ecltattgctrses
61
(1957)
cn
1661.
(X9.)7) 2855). d’lous, Gauthicrs-Villnrs,
Paris,
Proc. [..-I. E./l. Co,?/. ott Radioisotopes i,t the I<. A. ICRAUS, M. 0. 1’IIlLIPS AND 1;. NELSON, Vol. 3, I.A.E.A., Vicnnn, 1962, p, 387. Whys. Sciemxs arrd Itrdttstry. z9G0, Copotlrrcgett, x5 I?. NELSOS, T. ~IURASE AND 1;. 11. I
_4md. C/tint.
.4&a,
.+z (1gG8)
67-77