synthesis, ion-exchange behaviour and analytical ... filek. gopal varshney ph.d. analytical...
TRANSCRIPT
SYNTHESIS, ION-EXCHANGE BEHAVIOUR AND ANALYTICAL APPLICATIONS OF SOME INORGANIC
MATERIALS BASED ON TETRAVALENT METALS WITH SPECIAL REFERENCE TO
TITANIUM (IV) AND ZIRCONIUM (IV)
DISSERTATION SUBMITTED TO THE ALIGARH MUSLIM UNIVERSITY. ALIGARH
in part ia l fu l f i lment of the requirements for the award o f the degree of
MASTER OF PHILOSOPHY IN
CHEMISTRY
BY
VIRENDRA KUMAR SAXENA
DEPARTMENT OF CHEMISTRY ALIGARH MUSLIM UNIVERSITY
ALIGARH (INDIA)
1 9 8 4
DSG35 / r
DS635
K. GOPAL VARSHNEY PH.D. ANALYTICAL LABORATORY
CHEMISTRY SECTION
FACULTY OF ENGG. & TECHNOLOGY
ALIGARH MUSLIM UNIVERSITY
ALIGARH-202001
(INDIA)
C E B f X r X C A T K
It Is to emrtttf that tlio work |ir«Miiit«d
in t h i s M.Riil. th«s l s i s an original eontrilratloB
of th« oandiAate «n4 i s «aita1>le for sntmiasion.
/ CG.Vari^nay /
C O N T E N T S
PAGE
AeKN0VIi:Tn!liW.T«T ( 1 )
LIST OF FUBLTCATIUNS (11)
LIST OF TABU.S ( i i i \
LIST OF PIGlifttiS < lv )
CHAPTLH ~ I
XNTROntjCTION 1
HT^FERt NObS 10
SHAPTfcR - I I
S¥NTHi;Sf8 Asm lON-EXCn*'ill(2i KiHAVlOUn OP TfTANIliM(IV>
AnSE?K>SIl.ICAri3 CA1?I0?3 BSCHASClIBj SiPARAflON OF
MI TAL IONS 13
EXfi;aiW:NTAL tk
fllSCUSSlON 3 *
HEFE RENOIR S 3S
CnAI^ER « 111
QUANT IT AT TVI. SEPARATION OF IRON FROM SOMi. MULTIVIT^TN-
MUtTP!lNER.\L FORNICATIONS USTNtt aiaCOKlUN(IV) ABSt.NO-
fflOSPHATl. COLUMNS %0
BXIHRllfeNTAL hi
niSCUSSlON %3
IKFBN^NCBS 46
A C K N O V L E T > O E M E M T
T •xpreaft my ulnoere thanicfi to ^r , !C.O«yartbney for hiii
able gaiffance anrt lcln«1 fiupervialoo an* t o 1*ir, K.T.Nasoen for
providltif; the reaearott f a o i l l t t c a , I also thnnk ^r«. Sanjay
Agarwal anA icanak Varahney for the ir Rraat help ''urtoi thta work,
The kind cooperation provWe«S by ^r» M.S.Rathl, Bolentlat 'n*,
Vadla Tnatttute of Htwalayam Geolo*»y, liehra«1un. If? frateful ly
ROknovl^O^eH in uaing the inatrumental f a c l l l t i e e of the
Tnatltate,
The klnfl, whole-hearted oooperatlon end affeotloa
extended to rm ceaseleaely durtng tb le perlo<i by tuy family
mefibera, frtends and col league a leaves me btg!»ly obliged and
l^ratefol,
Finally, T gratefully acknowledge the finanela1
aeaiatance provided by the Counoll of Soi<*ntifio an^ Tndtistrial
Reeeareh, New T»elhi.
/ V.IC.Saxena /
( 1 )
L I S T 0 F P O B L I C A T I O N S
1 . QUANTITATIVE SEPABATION OF IRON FROM SOME MULTIVITAMIN.
NULTIHINEHAL FORMULATIONS USING 2IRC0NTUM(IV) ARSENOIBOSFHATE
COLUMNS.
Anal .Let t . (Accepted>•
2 , SYNTHESIS ANB ION-« JBCHANCSI HBHAVIOUR OF TITANIUM (IV) ARSE!»-
SILICAIi: CATION ElC!IAN(2Sat ^PARATION OF METAL IONS.
Solvent Extract ion And lon-Sxchange (Co««unlcated).
( 11 )
h i s t O F T A B L E S
TAmi^ X
TABLE TT
TABU:i m
tABm IV
TABI£ V
TABUS VT
TABLE VII
TABLE V I I I
CUNMON COWORCTAL XON^XCHANGERS %
lON-ESCHANCfti CAPACtTY OF TTTANIC«!(TV) AHSLNa-
STLTCATli BY VARYING TB. GuNULKTBATlOH OF TIB
MI3n*:G SOLUTUN 16
lOH^XCnANGl. CAP^VCITY AND HIYSTCAt APS>I:,ARANCE
OP TAS*3 AFPSB mvATINQ TO VABIOUS TLMB IIATUt%:S 18
CHEMICAL STABILITY OF TAS.3 29
KQ V A L U E S OP so^iii ca^nm MCTAL I O H S on TAS.3
IN DiFFBec^rr mntA 5 1
mm BINARY Fi3PAElATlONS INVOLVING Pl»(II) OU
TITANIBM(IV) AflHiNOSILICATU COLCHIS 32
SOm SALILNT PEATUKCS OP TBE KLPASATIUJI OF
p e ( i i > rmn oimn MITAL IOHS I N SOMI syNTimxic
MixTum^s OK oC^AP COLUMNS 44
QOANTITATIVI- SEPARATION OF P e ( l l ) FROM 0TW.8
METAL IONS IN VAfllOlIS MULTIVITAMIN-MULTIMINERAL
FORMULATIONS MARfa Tt.T> IN INT>TA OH o^-ZAP
COLUMNS %5
( ill )
L I S T O F F I G U R E S
PAGE
FIGURE 1 STRUCTURE OF AN lON^XCHANGE RESIN 5
FIGURE 2 BLUTION BEHAVIOUR OF T A S . 3 AT ROOM TEMPERATUHE I9
FIGURE 3 pH TITRATION CURVES FOR TAS.3 USING DIFFERENT
TITRANT SYSTEMS 20
FIGURE k {fi TITRATION CURVES FOR TAS.I7 USING DIFi!ERBNT
TTTRANT SYSTEMS 21
FIGURE 5 THERMOGRAM OF TITANIUM(IV) ARSENOSILICATE 2%
FIGURE 6 INFRAREH SWICTRA OF T . A . S . I N H * FORM 25
FIGURE 7 X-RAY DIFFRACTION PATTERN OF T . A . S . - I 7 26
FIGURE 8 SEPARATION OF P b ( l l ) FROM OTHER METAL IONS
ON TAS.3 COLUMNS 33
( ir )
C H A P T E B - I
XNTBO1I0CTION
1
l0B<-«zeli*ng0 has becone one of the aost important
t«ehnli|u«« In rooent t l i ie . An lon-«xoh«nger nay be defined as
a «tH>«tattO« Containing lout ilhloli can be exchanged with other
iona of the satRe e lectr ic charge anfll aupplled from an external
aource. As t h i s definition i s too wide for practical purposee,
an ion-exchanger for use as an analytical tool i s defined as a
solid oontainini; a oationlc or anionic species supplied fro« an
external solut ion. An ion-exchanger may be eith<^r organic or
inorganic in nature. For excfitple, T»owcx-50 i s an organic ion-
exchange resin vhlob consis ts of a highly cross-linked sulfonated
polystyrene polymer net woifc» If free sulfonic acid groups are
present, the resin i s said to be in H form. When i t i s immersed
in an aiineous medium i t behares as a strong acid end the sulfonic
acid groups are completely dissociated. Hie acidity of the
aqueous medium within the resin structure i s approximately 5N, Tf
i t i s treated with alkali the acid i s neutralised and the exchanger
conirerted to the appropriate cat ionic form. A similar exchange of
cations w i l l take place between the resin in one oati(Niic form
and another cation in solutitm. The process may be represented
by the following equatitm, where R ' represents the poljraer net work
and A and B are cat ions .
R"*A* • B* ' ' ' H~B* • A*
Tbe structure of the polymer net work of an ioB-ezchanfer
r«slii Is ^own In figarc^l. The anions present In the solutions
do not take part in the exohanjEe process to an appreciable extent
since consideration of Donnan equilibrium and the insolubi l i ty
of th^ exchanger anions shows that the anion in solutiim oaa aot
enter the net worlc. An ion--exohanger may be a strong or a weak
depending upon the nature of the groups possessing the exchangeable
ions in the matrix. Further, i t nay be a cation exchanger or an
anion exchanger. TablooT summariaes some of the ooisnonly known
ion exchange res ins . Organic resins have great u t i l i t y in
analytical chemistry as thoy can be used for achieving sonw very
d i f f icu l t separations. The most striking examples being the
separation of rare earths* different valency s tates of a neta l ,
amino acids, and sugars. The reasons of the ir wide spread
analytical applicotions are as follows}
(1) The high ohemiocl and rr^chaniocl s t a b i l i t y .
(2) Bigh ion-exchange capacity.
(3) High exchange rates .
(h) Poss ib i l i ty of selecting the fixed ionic groups and the
degree of cross linking of the matrix.
However, the main drawback has been their ins tab i l i ty at high
temperatures and under the environment of strong radiations.
For th i s reason an interest was revived in the study of inorganic
ion exchangers as they are superior to the organic resins in their
thermal s tab i l i t y and resistance to ionising radiations. For
example, s e o l i t e s oan be used as catalysts for gas reactions at
temperatures well above the range in i^toh the resins mre s table .
3
^ ^^lXv\1^ uiCh flKi-d chiiirfi?^
(^ C o u n t e r ions
.r-\ \Z) C 0 - i 0 n s
FIG. 1 STRUCTURE OF AN ION-EXCHANGE RES!
(SCHEMATICS)
a 5
3
m
S
O o
s o o
CO
o « « o
fi
>4
t a
0
2
I
i
m u B
JO
o u §
ex • • 1
i f \ 4 KN
* *
6 «H
5 B
^ ^
p 0
• in •
o\ •
•«•
• CM
QD •
*
•
1
» r\
vo •
vo
• K>
l f \ •
o\
0
VD •
01
m 0
o\ •
yt
• 0 0
es n •0 B (0
B •S 0 «
• 0
0 •-4 a 0
e « s » 0 |Q
•0 S a tH UD B M
• •e •>
• 0 0
•> •H
a g « 0i«
• 0
0
«0 IB « 1 h 0* p4 CO 0 1-t 6 fl) ja 0
§ *-< •
8 O * M
O • W Q ID CD
-. - * S i g a o u n o 0*
(0
o CO 4 * er S t -B P i l
JB U » Q o Xi CE! &« O
§ ^ 1
H
0
P-(
h
^
5
^
M « » e 0
tf\ Cs> 01
t <e ¥ i 0
69
KN VO
1 0
« 4* ^ »-• 0 8
g H
«
ti r-* u « .0
i!
lf\ 'H CM
•s «B ^ 0
o o
o »
1-4 o a
• 1 ^
B
» B
•**
K O At
2 S o o I f ? *?
S 8
*-• t O ^ K B B H • 44 O ^
• «• »•
u &> 8 O
a o
5
w B «4
B Ji O B
l M « iN
C4 « I (M • a <B •
B.O • U fi O
4 BJi O B
<C I 8 CB
S.O « h fi O
ei
V6 tt% • • a tr\
0 •
K\
0 •
1 ^ m
o 0 0 <B (D « n •o 8 a g « «
• 0 0 H CO 0 «H
e 0
6 g fi
u «B CD (3
m «o C CD
e € «
o o
«9 O
o u CD tt CO
n 8 CO
§ ^
o o
« • 4» •»
« « CP
• fi <
a M
I
I
o-^ ^- ' •^ CM
1? i-<
0
8 CD
s B
»
o fin
T
«>
I B.
CD M
* o .U 6 CO - H
5 » CO
5
Tli« laorsanlo Ion txehangcr gel* offer adTantagoo In the
deoontaalnatlon of cooling water In nuelear reaetora irhere both
the tetnperature and radtatione ler^l are high, Furtheraore,
oryatalllne ion exchangers with regular frame work atruoturea
often show higher s e l e c t i v l t l e e than materials with irregular
gel struoturea.
Synthetic inorganic ion exchangers have earned the ir
position in the f ie ld of Analytical Chemistry during the last
two decades, Amphlett ( i ) and Clearfield (2) mey he regarded
as the pioneers of the f ie ld who have init iated and developed
the field to the present day s tatus . On the hasls of their
struotare and chemical nature these materials can he c lass i f i ed
into the following s ix groupsf
( i ) Insoluble acid sa l t s of polyvalent metals.
(2) Hydrous oxides of polyvalent metals,
(3) Salts of heteropoly ac ids ,
(%) Insoluble hexaoyanoferrates(II).
(5) Miscellaneous inorganic exchangers e , g , merearbide s a l t s
and potaasium polyphosphate,
(6) Synthetic aluminoailicates.
Although the materials of all the above categories find
important applications (5-5)t our main emphasis will be on the
insoluble acid salts of polyvalent metals, as they possess much
satisfactory pn>parties which are produced by combining generally
the oxides of group III, IT, V and VI of the periodic table, A
large oowbinations of such materials have been prepared by mixing
6
phosphorlQ, ars*Blo, m>ly1»dlo, tunf^stto, antlaontc and vanaAlo
aolda with sireoaluai, tltanltim^ t i n , tliorliw» oerluiB» iron,
ohronltM, ntobtum, tantalun, bla»uth, nickel , cobalt a t e .
AfnongBt the large aumher of Inorganic Ion exohfingerm
alrconluwi fibospfiate Is probably th© wost ex^»aptlve^y studied
tBatcrtal so far both In the aworphoua and oiyatal l lne formn.
On tbe baelfi of ebemloal analysin Baetale baa easlgned a atruo<
tnre^ tbown belows
HgPOj.O
Zr 0
on
n^voyo OB
Sr 0 ^Z— .HgO
HgHlj.O HgPOJ.0
P 0
OH
Tts manifold applloatlcma (2) l l luatrate well Ita
li»portanG« as an ion exchanger. Tor example, i t has been
ut i l i sed for the purification of coolant water in oloaed cycle
nuclear reactor ayetews, in which the teesperature of water i e
approximately 3CK) C and the preteure ia about 100 at* . Another
important uae of amorphoue alroonium phoaphate baa been in the
portable renal dialyeia ayatema. Urea, which ia the compound
dialyaed from the blood atream in the greateat quantity by
a r t i f i c i a l fcidneya ia not readily aorbed by common aorbente.
In order to remove i t from the dialyaatea, i t ia hydrolyaed to
ammooiiMi carbonate by the ensyme ureaae. The dialyaate ia then
7
pasMd 0T»r • eoluMB oontainlni! aotlrated oharooal and xireoaiUM-
phoaphata. Xlreonlam phoaf^ate takaa up anmonlttar Ion or forwa
tntaroalatad eompoand with MH.« Other organic oontaalnanta ar«
Borhad by the activated oarhon. Production of apherlCPl part i c l e s ,
precipitation of a l l l ca gel on to the zlroonlum phoaphate and
production of fluroethylene (fluroplaat) coatlni; are nome of the
further atte<npt8 to Improve the atabl l l ty of slrconlun phoaphate
for Its %rlder use In lon-exohange technology* This material has
also found application In water aoftenlng prooenees. ft haa also
been used In gas chromatography for the separation of atsines on
i t s columns using NH as the mobile phase. Similarly, ohloro-
hydrooarbone and oeroaptans haye been e f fec t ive ly separated on
crystal l ine potassium asirconium phosphate. Becent applications
of zirconium phosphate include i t s cata lyt ic behaviour* Use of
inorganic ion exchangers as membranes i s important from the
industrial point of view* They would permit a higher temperature
to be used and a greater eff ic iency to be attained as compared
to the organic resins* Exchange membranes have been made from
hydrous thorium and slroonium oxides which have been found useful
for demlneralisatlon of saline water* Another interesting
application of inorganic ion-exchangers has been their use as
antloorrosive additives, tabody and Ronay prepared a thin sheet
of exchanger which, when placed around a s tee l tube inserted in
the earth, acts as a protector*
Since titanium resembles xlrconlum in i t s ebemical
behaviour the ion axobaBgers based on t h i s metal have also
8
rtotir^d attention. Some of the Important Materials of th i s
type whioh have shown good ion exchanica behaviour and analytical
appiioationii are tltanittai-silloate (6)* titanitm i^iosphate (7<-8),
hydrous titaniuli dioxide (9'*12), titanium vanadate (13)t t itaniun
hydroxide (i4<»17) and t i taniun tungstoarsenate (16)•
Heoently double Belts have received attention as ion
exchangers. They have shown a more pronising ion-exchange
behaviour. Zirooniuis phosi^osilicete i s pnibably the f i r s t of
t h i s c l a s s which has been used for the isolat ion of plutoniun
(19-21)• Similarly titanium phosphoeilicate has been used (22)
for the separation of radionucletde. Quite a good nunber of
double s a l t s have been prepared in these laboratories based on
Sn(lV), Th(IV), Ce(TV), Cr ( l l t ) and Zr(TV) which have shown sowe
interesting ion-exchenge properties (23-^1)# Amongst them Zr(IV)
arsenostl icate and Zr(TV) arsenoi^osphate have i l lurtrated the ir
applications in the analysis of rooks, a l loys , end pharmaceuticals.
They have also shown a good chemical, thermal and radiation
s tab i l i ty (42) ,
Although the fieli^ of inorganic iou'-exchnngers has seen
a tremendous development in the recent past, one of the most
baffling problems has been to produce a real ly reproducible and
and stable material. Furthermore, i t i s important to select a
material useful for the solution of some real problems. Our
recent approach to u t i l i s e inorganic ion exchangers In the analysis
of pharmaoeatical products has made them more promising. The
9
pr»««Bt wofic i« In ooDtlnuntion of oor sucb an t f f o r t , A oew
ion «xohanK« nat tr la l baaed on t ltaniun, arsenic and s i l icon
has iMen prepared and i t s ion exchange properties 8ti:^ied a«
eoMmi^sed in Ohapter-TT. Since t h i s material needs sons wore
studies before i t s utiliasation in the analytical f ield can be
made, another naterial of the aatie c lass v i s . zirooniini(IV)
arsenoi^osphate has been selected for the analysis of s«KHe
drui; formulations, Chapterollf summarisses such a study.
10
MEFBgHCBS
i r 0»9.A«phletty ^looxsanlo Ion Eacoliaaxerti", ElMYisr, London
(196*).
2 . A,Clearflel« (Ed,), "Inorganic Ion Sxctiange Matertalf",
cue Press Inc . , Boos ttaton, Florida (1982).
3, H.f.Valton, Anal.C!i«m«, ^ , 15R (19^)*
%, y.Pelcarolc and V.Vesely, Talanta, ig , 219 (1972),
5 . V.Pskarek and V.Vosoly, Taianta, 1^, 1245 (1972),
6. G.T.nesal, B.H.Baxl, Indian J.Teohnol,, 16(5) , 20^-6 (1978).
7. Yu.B^nolmatov, R.T.Fogodin, Neorgan lonoobmen Materialy,
(2 ) , 86-8 (1980).
8» Yu.A.Ajana'ev, N.B.Savanofe, L.T.Aashipa, SP STL 512 Ichp - 1»82,
(1982).
9 . Taiceyosbl Sasaki, Tu.Koiaatsu, Yoshinori Fajikl , Sep.Sci.
Teohnol, i 8 ( l ) , A9~58 (1983).
10. T.M.Valentine, R.A.J.Sanbell, Nuol.Chen.Waste Manage,
2(2) , 125-30 (1981).
11. T.N.PerektaoshSTa, L.M«Sharygin,T.O.MaIykh, Radiokfiimiya,
2*(3), 295-8 (1982).
12. li.A.BersehkoTa, A.A.GuasalroYS, To.A.Baliyrenko, Neoi^an.
Tonool>Men Materially, (£) , 72-6 (I98O).
13* Myong Rwa-Kin, T.K.Su.U, TT Sang Kia, Punsok HWahak,
(3) , 15-21 (1979).
1%. M.t>.«etenekov, Y.A.Yasileirskii, Yu.Y.Egora, T.A.Nedobukh,
RadlokhiMlya, 24(%), 419-2* (1982).
11
15* B,p«Nlkol*skll, E.D.Makarova, F.A.Bellnskaya, L.N.TolkaohaTa,
N«orgaii,fonoo1)iii«n Matertaly, (2 ) , 26«>51 (1980),
16. B.P.Nlk«l*Bkii, fi.P.MakaroTa, F.A.Belinakaya, L.N.Talkaoheva,
Ibid, (2 ) , 51-72 (1980).
17» F.A.BellnPkaya, E,t»,Makarova, Tnnoylobmen lonor^etrlya,
i f 33-9 (1976)•
18, Jagdish Prasad Rawat, Vieaood Akhter Khan, Anii.Chin*,
62 (9-10), 525-32 (1979),
19* n.Nauffiaan, Kernanergie, 6, 173 (1963)*
20, K.y.Barsukova and O.N.nadionoTa, Badtokhlmiya, 14, 225
(1972),
21, R.Ootae, P.Sohenken* W,T)ole8legen, L,H,Baet6le and Mn< hont,
J.Inorg.Nuol.Chen,, 2§t 665 (1974),
22, S,J,Na(nrl, D.HuyB and L.H.Baetale, ib id , , ^J, 4317 (1971).
23, S.G.Varebney and A.A.fChan, Talonta, 2^, 528 (1978),
24, K,G,Tarshney and A.A.Kban, J.Inorg. & Huol.Chea,, 41 , 241
(1979).
25* K,G,Tarsbney, S,Nabeed, A,A,Khan, S,N,Taadon and C,B,Gupta,
Cbroaatograpbla, 12, 413 (1979).
26, K.G.Tarabney and A.Pranadaa, J,Liq,Cbroaatogr*, 4 , 1245
(1981).
27, K.G.Var^ney and A.Prenadaa, Ibid, , f , 915 (1981).
28, K.G.Yarabney and A.Pranadat, Indian J,Cb«n,, ^ , 841 (1981),
29, K,6,Tari^a«y and A,preiMidaa, 8«pn,Sol, & Tech,, 16, 793
(1981),
30, K,G,Varabn«y, A.A,Kliaa and A.Praaadaa, Annall Dl Chl«loa,
579 (1981).
12
31 . K.6.T«r«iineyf U.Sharna, S.Ranl and A.Premaaas, Sapn.Sei, A
Tech., 12(3)• 1527-43 (1982).
32. K.O.Tarshney, S.Agrawal and K.Varehney, Ib id . , 18(1), 59-72
(1983).
33 . K.O.Taridiney, S.Agrawel, K.Varshney, U.Sharma and S.Ranl,
Badloohem.RadlonaI.Lett., ^ ( 3 ) » 141-46 (1983)*
34. IC.O.Varehney, S.Agrawal & S.Varshney, Anal.Lett. , 16(B9),
685-92 (1983).
35. K.O.Varshney, K.Vftreliney and S.Agrawal, Sepn.Sol. & Yeoh.,
18(10), 905-15 (1983).
36. K.G.Varshney, S.Anwar and S.Z.Qureelil, Anal.Lett . ,
16, 1093 (1983).
37. K.O.Varshney, S.Agraval and K.Varshqey, Ib id . , 16(A17)
(1983).
38. K.G.Varshney, A.A.lQban, A.Meheehwerl, S.Anwar and U.Sharma,
fnd.J.Tech., 22, 99-103 (1984).
39. K.O.Tarshney, S.Agrawal and IC.Vareliney, J.Llq.Chromatogr.,
2 , 201 (1984).
40 . K.O.Tarshney, Uma aiarma and S.Ranl, J.Tnd.Chen.Soo.,
61(3), 220-24 (1984).
41 . K.G.Varshney, San jay Agrawal, Kanak Varahney and S.Anvar,
J.Llq.Chromatogr. (Tn Press) .
42. X.G.yarrtiney, S.Agrawal, K.Varshney, U.Sharma and S.Ranl,
J.Radloanal.Nuol.Chen., 8£(2) , 299-308 (1984).
C H A P T E R . IT
SYNTHCSTS AN1> lON-EXCHANOfc; DLHAVIQUR OF
TITAtilOM(TV) ARSENOSILICATE CATION ESCllANGERt
SEPARATION OF METAL IONS
13
INTHQIIUCTIOW
Tltanlttm and slroonlum based Inorganlo lon-axohangera
hare shown t b e i r aaaljrttcal iiiipoi*toBC« In many ways, Zr(T?)
and Ti(TV) arsanophosphates have been used in the a n a l y s i s of
cer ta in a l l o y s and rooks ( 1 ) . Also t i tanium tuni;8toarsenate
has been used (2) for the separation of Pb(TT) from Mg(TT),
Zn(Tt) , Mn(TT) and Ca(TT), Certain other double s a l t s based
on t i tanium have received at tent ion as inorganic ion-exchangers
such as phosphos i l ioate , taolybdoiSiosphate, tungstophosphate and
vane^ophoepbate (3-6) • Howeirer, as the l i t e r a t u r e sbowti
arsenoeil icates arc the least studied materials. Only siroonium
and t in based arsenoeil icates hove been reported (7*8) eo far,
although, the single arsenate and s i l i c a t e sa l t s have shown
ear l ier (9tlO) a much promising ion-exchange behaviour. Tn
view.of th i s titaniumoarsenostliCQte has been taken up in t h i s
study to evaluate i t s ion exchange behaviour and analytical
potential . The following pages summarize the results of such
an e f for t .
14
EXPERIMENTAL
Tit an Ian tetrachloride used in t h i s study was a product
of Flulca A6, Chemishe Fabrlk CH~9470 Buohs, while solium
metasll lcate and nrsenlo acid were ohtalned from H.TI,11,Poole
(England)• All the other reagents and chewtoels wore of
Analar grade,
TnstrmeentG used for the various studies are given belowf
SI, Studies Btade fnstruisent used and i t s Hodel/Make
1, fifl seasureraents fl! meter. Model LT-10, Clico (India).
2 , Infra»red absorption Becktnan IR-'SO spectrophotoineter,
3 , X-ray diffraction Philips x-ray diffraction unit with a Ctt-Koc target ,
4 , T.G.A, Themobalanoe Consisting of a Cohn RG Electrobalance (Model 2050) and a nichrone wound res i s t ive furnace,
SYNTHESIS OF THfc lOW-EXCHANGE MATbRlAL
Different samples of titanium arsenosi l icate were
prepared by the following methodt
Aqueous solutions of titanium tetrachloride arsenic acid,
sodium s i l i c a t e and RNO. (IM) were mixed in equal volumes with
15
eonstant s t trr lng . The gel obtained was kept at room temperature
(30 C) over night anrt f i l t ered , washed with demlnerallzed water
<nMV), and dried at %0 in an a ir oren. The dried product was
cracked in IWW t o obtain granules which were converted into the
H form with IM HNO.. A few samples were also prepared by
refluxlng the mother liquor obtained by the abore method in
4M H5I0- for 100 h. Table-II suwstariaes the sal ient features of
the various samples prepared under varying conditions.
IQN SCHANCaS CAPACITY ( l . e . O . ) iiiir-- I III I •• " ' - - - i • II III I • ii i i I i i i i i n l i—1 *•!
The ion-exchange oepacity was detensined by the oolumn
process taking 1 giR of the satnple (H form) in a glass tube
( i , d . ' ^ 1 cm), f itted with the glass wool at i t s bottoa. A
solution of IM NaNO, (%00 ml) was passed through the coluom
maintaining a flow rate of'-^10-12 drops/min. and the effluent
was t i trated with a standard UaOH solut ion. The Na^^xchange
capacities (mllllequlvalents per dry gran) of different samples
are given in Table-TI.
Bepending upon the highor ion-«xchange capacity and
apparent chemical s tab i l i ty sample TAS-3 was selected for the
detailed s tudies .
THERMAL STABILITY
Several 1 gm portions of the sanple TAS-3 were heated
at different temperatures in a muffle furnace for 1 hr each and
the l . e . c* was determined as usual after cooling them to the
16
TABLE « n
IOII lCHANq& CAPACITY OF Ti(IV^ ARSBKQSILICATE SAMPLES FHEPAmP
IT YABTINC THB CQNCKiJTHATION qP tms; MIHIM^ SOMTTtOKS
Sample No* Mixing oonoentratlon of the oomponente I . e . e . 1 i (meq/dry gw)
Volttne Ratio of mixing
TAS - 1
TAS > 2
TAS - 3
TAS - k
TAS • 5
TAS - C TAS - 7
Volttne Ratio of Mixing
TAS > 8
TAS - 9
TAS - 10
TAS - 11
TAS . 12
TAS - 13
TAS - tk
TAS - 15
TAS - 16
Volane Ratio of Mixing
TAS - 17*
\
1
{
1 t
Tl
O.IM
0.2M
O.IM
0.^
1,0M
0.2M
0.5« 1 t
Tl
O.IM
oaM O.IN
O.IM
0,2N
0.2M
0.6M
0.8N
l.OM
1 t
Tl
©•3K
1 S
HAS
0.5M
O.IM
0.2M
O.IM
O.IM
0.^
0.5M
1
NaAs
O.IM
0.2M
0.5M
l.OM
0.5M
0.5M
0.5M
0.5M
0.5M
1
nAa
0.3M
1
Nasi
O.IM
O.IM
O.IM
O.IK
O.IM
O.IM
0.5H t 1
NaSl
O.lM O.IM
O.IM
O.IM
O.IM
O.IM
O.IM
O.IM
O.IM
f 1
Nasi
0.3M
1.15 1.12
1.26
1.23
0.81
1.18
1.01
1.05
1.15
1.20
1.02
1.06
0.99
0.89
0.90
0.83
0.00
Tl « TltaalttM t e t r a o h l o r l d e , HAs • Arsenic s o l d , NaAs « Dl sodlua arsenate , NaSl • Sodlua s i l i c a t e .
Reflttsed for 100 hours .
17
roon ttt«f»*r«tttr«. Table-TII tumiarlxet tbe re su l t s ,
ELPTIOK tHAYIOUR
To finA out the •lutioti bebavtour, IN NaNO. solution was
paeaed through a colunsi oontalning 1 gin of the exohanger in
H^ form anA the effluent was collected in the fractions of 10 ml.
These fraetioDS were t i trated against a standard NaOR solution
to determine the B eluted out. The histograms are shown in
figure•2.
pE TITBATIONS
They were performed by the isethod of Topp and Pepper
(11) as followst
500 mg of exchanger (B form) was taken In each of the several conical flasks to which were added equimolar solutions
of metal chlorides and the ir corresponding hydroxidee in different
•olume rat ios , tbe final volume being 50 ml. The jM values of the
solutions were recordei' after keeping them over night for e q u i l i
bration and were plotted against the mi l l l equivalents of OH"
added. Figures 3 and h summarize the pB t i trat ion curves for
the SMiples TAS-3 and TAS-17 respectively.
COMPOSITION
Composition of the samples TAS-3 and TAS-i? was determined
by the standard methods (12,13) es described belowt
18
O
M
»: a
o
<
o to
I •>
O <B
c m & 4* e 6 m
1 <
CO
i i o
I o
o H
S
<
« M C (9
•J "
w4 (B CP i ti-V ffi «B i
c
a ja
e
I
e
ft 4* B
8 1 o
s CO
p.
\ 0
• <•>*
s •
o OB • O
fi •
o
in o •
o
u Si
19
O o < tn I
(/)
<c H o CSC
"o O « j X UJ
o
- J UJ
6
e 9
e 9
P « t t t ) « j ^ H i ° t«|oui (U
20
" ^
A NaOH / NaCl
O KOH / KCl
LiOH / LiCl
OS 1,0 1.5 2 O
m mo les 0 f OH added
2.5
FIG 3 f H TITRATION CURVES FOR TA.S DIFFERENT TITRANT SYSTEMS
•3 USING
21
3 -
4 NaOH /NaCl
O KOH / KCl
© LiOH / L iC l
J_ J., O S
. _ i 2 O 2 S l O t. 5
m mo I f <s of OH added
FIG.4 PH T I T R A T I O N C U R V E S FOR TA5-I7 USING DIFFERENT TITRANT SYSTEMS
22
1>«tT»twtlon »f Titmluw and Si l icon
To an aecuratoly weighed amount (100, 200 and 500 ng)
of the frawdered savitple irae added a small amoant (10-15 «il) of
eonoJIgSO^ and the alzture was evaporated to dryness on a steam
bath. The treatment was repeated with additional oono.HgSO^,
The residue was taken ap In 5 nl ooncH^SOji and 200 • ! of t'ffV,
digested to dissolve the soluble sa l t s and f i l t ered , washed and
Ignited. The Ignition product was weighed to give the tota l
weight w^ of oxides (TlOg * S10n)« tt was then treated with
a mixture of OP and n^S^^ followed by evaporation npto dryness.
The residue was Ignited and weighed to give the weight (w.) of
TlOg. The difference i»j-W2 6*^^* the weight of SlOg,
T>eterwlnatlon of Arsenic
An accurately weighed amount of the powdered sample was
dissolved In a minimum amount of oonc.RgSO;!. After dilution to
about 100 ml with vm titanium was precipitated with a freshly
prepared aqueous solution of oupferron (65(), f i l tered on a
Whatman No. k2 f i l t e r paper. The f i l t ra te was boiled with Rlf0«
and a few drops of 30^ H Og to oxidize the organic matter. After
cooling I t , 1 ml of T)*fV and 5 ml of conc.nCl (both previously
boiled and cooled) were added followed by addition of 2 ml of
411 KT. The solution was kept for 10 min in a stoppered flask
and t i trated against O.OlN sodium thiosul|rfiate after adding
5 ml of i01( starch solution •
23
THBRMOOKAYIMETRTC AWALTSIS
Pigtti« 5 thows tiM peroent weight l o s s occurred in ttie
eawplea TA8.3 and TAS-l? on heating then upto 1200 C*
IWFRA^KP gTUPTES
t . R , atuflles were perfonne^^ osine; the KBr p e l l e t rnethofl.
Figure 6 lAiowa the c o ^ a r a t l v e 1 , 8 . spectra of aemples TAS- 3
anfl TAS-17.
X RAY STUy>ICS
Figure 7 ebovi^ the x-ray d i f f r a c t i o n patterns of sample
TAS-17* Howevor no remai^ablc peck was ohtained for sample TAS-3.
CHE fTCAL STAB7LITY
The chemical s t a b i l i t y In various so lvents was detemined
for the sample TAS-3 as fo l lows!
250 lOg port ions of the sample were kept with 23 ml each
of the various s o l v e n t s for 2k hrs with intermittent frttaking.
3 ml of the supernatant l iquid was evaporated t o dryness and
redlsso lved in 23 ml of t)MV, Titanium, arsenic and s i l i c o n were
then determined separate ly by the standard methods given bel«wt
(a) WTERMINATIUN OF TITAHTUM
3 ml of the sample so lut ion which i s in equil ibrium with
t i tanium a r s e n o s l l l o a t e waa mixed with 0 . 3 «1 of a 30)K HjOLtolutioa
24
O 2 0 0 4 0 0 & 0 0 ® 0 0 1000
T»mp«ratur9 ( C )
12 0 0
riG. 5 THERMOGRAM OF TITA^JiUM 15V)ARSEN0S1L!CATE
25
c
c
'r-
& 0
<o
ao
4 0 0 0 SOOO HOOO 15 0 0 lOOO
Wav!? number (Cm~^ 3
3 OO 2 5 O
FIG.6 INFRARED SPECTRA OF T.A.S.IW H FORI
26
m <
PI
J L^.^ i L 1 <tt lA o
o> n
m fM
fV
P--
m
»
ij>
^ • • ^
6»
o» O • > —
© ns
1
<
U-O Z Ci LU H f
< O.
2 O
u «^ cr:
o
>-<
1 X
6 u.
^ ) i i u « ; y |
27
and th« Toluae was nade 25 nl by addinx 10% eulphurlo aold in a
•oluaetrlo flask* The absorbanoe of the ooloar de^eloped was
neasured at h±0 nil against the reagent blank (14) .
<b) BBTERMINATION OF ARSENIC
I t was done by the nolybdenum blue method (15)* The
reagent solution was prepared by nising 10 nl of solution A
(1 gm amaoniun nolybdate dissolved in 100 nl of 5N H SO. ) with
1 ml of solution B (0.150 gm hydrazine sulphate dissolved in
100 ml of t MW) and diluting the mixture to 100 ml. It was
prepared fresh dai ly , 10 ral of t h i s reagent were added to the
sample solution (5 n l ) and the mixture was heated on a steam bath
for 15 minutes. After cooling, i t was transferred to a 25 ml
volumetric flask and diluted upto the mark with the reagent
solution. Tb*} absoxbance was taken at 850 n^ against the reagent
blank.
(C) PETEHMIWATION OF SILICON
5 ml of the sainple solutioa was mixed with 0.5 nl of 101(
annonium nolybdate and 0.1 nl of 50% H„S0^. The solution was
diluted upto 25 ml in a volunetrlc flask. The absorbanee was
taken at %20 n|i against the reagent blank (16) .
Table IV sumariases the solubi l i ty of the material in
various solvents . ~ -._
•••- ••* . . • i . ' ^
TABLE.IV
mmiCAL STABILITY OF TITANIUM ARSbNOSILTCATO. (TAS.3)
28
S o l u t i o n s (25 n l )
IH HNOj
SM HNO.
m BNO5
IM RgSO^
2M HCl
4M HCl
IM BCIO^
2?! HCIO^
IM CH.COOn
l*f nCOOB
0.05W NaOH
O.IOM NaOH
O.IOV KOR
IW KNO5
m NH^NO-
IM NaNO.
Affloui
T l
DA
I»A
BA
BA
TA
DA
1 .40
2 . 0 3
0 . 0 0
0 . 0 0
0 . 0 0
0 . 0 0
0 . 3 1
0 . 3 1
0 . 0 0
0 . 3 1
i t dl88oliW(9 In
a An
flA
BA
BA
!»A
nA
T»A
0.00
0.60
0.48
0.59
0.91
0.92
0.97
0.00
0.00
0.00
WR 1 "'
SI
DA
l>A
?»A
T)A
DA
DA
0.00
0.00
0.00
0.00
0.06
0.30
0.10
0.00
0.11
0.12
T»A Dl«solTt/l appreciably.
29
PISTBIBOTIOW OTimiSS
Blstrlliation stadlss were perforwed on sample TA8-3 for
liiffeiwn't «ot«l ioas to •arloiis iiolira»i^« an followftt
290 mg of the exchanger beade In H form were equillhrated
with the selected solvents (25 n l ) e i ther by shaking for 3«-4 h
or by keeping at room temperature for 24 h. The i n i t i a l metal
ooROf^ntration in the solution was so adjusted that i t may not
exceed y% of the to ta l ion-exchange capacity of the material and
the determinations were carried out •olumetrloally using EnrA
as a t i t rant (17) .
The S^ values as suramarized in Table—T were obtained
by the formula
d • "7" * I (w^/s)
I m I n i t i a l amount of the metal ion in the solution phase,
F m Final amount of the metal ion in the solution phase.
Y •> Volume of the solution (ml).
A « Amount of exchanger (gm).
SEPARATION ACHIEIfEII
The 6o-iOO mesh sized part ic les of the sample TA8-3 (2 gm)
30
iB th« B^ foFM w«re paok«0 In a glata tabe liaTiaK ao Intamal
dlaMeter of ^^0.6 on and f i t ted with the filaaa wool at Ita bottOM,
7h« ooluwtt v i i Viahed thoroughly with tmv and the analsrte aolution
was loaded on i t , maintaining a flow rate of "^2-3 dropa/nln.
All the metal lone except Pb(lt) were eluted out In O.OIM HNO.«
Pb(TX) was then leached oat with m NH-W,, The flow rate for
elutlon was kept 10-12 drops/win. The effluent were t i trated
for the ir metal Ion contents using B TA as a t i t rant . The salient
features of the separation are shown In Table ft and Figure 8«
31
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• • • * • • • • s * * ^ *
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s^ 4> < )<% S S & 8 Oi
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PISCUSSION
A n«w Inorg^nlo ion exchanger tltanlttn(tY) ar»eno«llloate
hat haan ayntliattsatf and atndied for i ta ion aisohanga profH»rtiaa,
The aNorphoua phaae of th i s vaterial (TAS-3) ahowa an appraeiahle
ion exchange oapaoity (1.26 meq/gai) nnd a good thermal a t a h i l i t y .
However, i ta crystal l ine phaae (TAS-17) ahows sero ion exchange
capacity, ft may Tie doe to the reason that on refluxing the
material for 100 hours the protogenio groups are los t and an
uncharged matrix i s fonned. In t h i s respect titanium arseno-
s i l ioa te d i f fers from other materials of th i s c lass in general.
For exsTople zirooniun i^osphate has been reported to gain i t s
ion-exchange behaviour after crys ta l l i zat ion , Sini larly i t
has been obserred in case of zirconium arsenophosphate (18) that
on refluxing for lOO hours in 4M RNO. It becomes crystal l ine with
an itsprovement in i t s ion exchange capacity. The x-ray diffraction
pattern (Figure 7) of TAS-17 shows several peaks with the following
d-Talaest
9.3015, 7 a 3 2 0 , *.9238, *.5715, 3.5309, 3.3984, 3.1839»
3.0153, 2.8465» 2.6882, 2.5902.
As Table-TTT shows, titanium arsenosil icate retains 571(
of i t s ion-exehange oapaoity even on heating upto 400 C lAiowlng
a remarkable thermal s t a b i l i t y . However beyond 400 C i t loses
i t s iiHi exchange capacity abruptly. The material, therefore,
promiaes i t s use at high temperatures.
35
HI* pH t i trat ion ounres (rigures 3 and 4) Indleate that
while the aworphous naterlal (TAS-3) releasee the R ioaa
ai^preolAbly* the erystal l toe «at«rial (TA8*i7) Ao«« BOt. This
hehaviottr i s in aocordanoe to the ir Ion exchange capaolt ies .
Furtbermoi^, 'rAS-3 shovs a very high rate of exchange for Li* as
compared to Na and K at the i n i t i a l stage, to general the
pR t i t ra t ion carves indicate a bifanctlonal behaviour of t h i s
acid s a l t .
The infra*red spectra of t ltania«(IV) arsenosll icate
both enorphoos and crys ta l l ine , are shown in Figure 6. They ~1 indicate the peaks around 500» 900, 1^0 and 3500 en . The
peaks in the x-ray patteni of TAS-17 are more d is t inct and
sharper than in that of TAS-3 peiiiaps due to i t s crystal l ine
nature. The above mentioned peaks oonfira the presence of
metal hydroxide, arsenates, s i l i c a t e s and water Molecules. The •1 peak at 1600 cm also represents the weakly bonded protogenic
groups responsible for the ion exchange eapaoity.
Figttre-5 ehows the therwograms of TAS- 3 and TAS-17.
As i t i s c lear from these curves TAS-3 experiences a more weight
loss on heating upto 1200 C as compared to TAS-17. Also, i t s
weight remains constant from 200 to 700 C. But TAS-17 has one
more step during th i s range. Since TAS-3 i s having a gel
character i t contains more water molecules than TAS-17 which i s
crys ta l l ine . And hov|Eie« higher loss in I t s weight can be
visual ised. The i n i t i a l weight loss vpto 200 C i s due to the
36
lo t* Of • x t t m a l water aoloottlos. Further l o s t at the higher
teiiperature Indioatee eon<1entatloii»
Figure 2 showt the e lot lon hehaTlour of TAS»3 In^lleatiiie
alwost a complete elotlon of the H lone In the f lrat 150 • !
of the ef f luent ,
Tahle>TV tumtnarlzee the retulte of the s tah l l l t y study
of tltanlum(TV) arsenoellloate In varlout to lventt . It Is
observed that the eubetanoe le not very stable In strong aold
media partloularly BNO., ^9^4 "Q^ ' CSl. However In HCIO , It
seems to be quite stable anil also In organic aolds# Alkalies
and sa l t s lltce SNO«t I ^NO* and Na!iO« do not dissolve the
substance to an appreciable extent .
A study of the distr ibution-coeff ic ients (Table-IV) on
tltanluiR(IV) arsenosllloate points out I t s extra ordinary
se lec t iv i ty for Fb(TI), On the basis of such a study separation
of Pb(TT) froiB several metal Ions has been t r i e d . As Table-VT
and Fig, 8 Indicate the exchanger can successfully be employed
for the separation of Pb(TI) from numerous metal Ions, The
results obtalne*^ are aoourate as the error range Is very low.
The advantage of the method Is that the separations oan be effected
on a email column containing only ^^2 gm of the exchanger and
using common and Inexpensive solvents l ike UNO. and NII.NO_, Also
the method Is rapid and the same column can be used several times
without a lose of I t s ef f lc lenoy. Lead Is one of the chief
37
pollatiBg •a ter ia la found In aquatle anA enYlronaantal asratems,
Tta ranoval and separation la , therafore, of great algnlfleanea
and tltanlun araenoailloate offera Ita u t i l i t y In auoh a eaaa.
The oliamlefll analyala of the salt reveal a the nolar
oo«npo8ttlon of TAS-3 aa 2t5s5 (TltAatSl) and that of TAS-17 aa
2tlt4t (TlsAsfSl), It oonflma the view that on refluxlng, the
protogenlo groups are lost generally attached v l th the arsenate
and s i l i c a t e groups thus resulting In the lost; of the oat Ion
ejEOhange properties of the nater la l . This point, however, needs
further Investigations based on the structural studies, before a
definite conclusion i s drawn In t h i s regnrd.
38
1 , K.6.Yar8liney» S.Afsrawal, ICYarsbney, A.Prtmadaa, M.S.Rattai,
P.P.Khanna, Talanta, 2 0 ( 1 2 ) , 955-8 Cl983)#
2 . J.P.Rawat, M.A.Khaii, Ann,Clii«,, 62.t 525-32 (1979) .
3« S.J.NaqTly T).noy8 an(f L.H.Baetsla, J.Xnorg.Nucl.Chem.,
2 1 , %317 (1971) .
4 . C.Czllioloy, L . S z l r t e s and L.Zslnka, Radio Cliem.lfadioanal*
L e t t , , 8 , 11 (1971) .
5 . J.P.Rawat and R.A.Khan, Ind.J.Chen. , IgA, 925 (1980) .
6 . N.jr.Singh and S.N.Tandon, Ibid, Ig^t * 1 * (1980) .
7 . IC.Q.Varahney, S.Agrawal and K.Varehney, Sep.Sol .Teohnol . ,
1 8 ( 1 ) , 59 (1983) .
8 . IC.G.Vareihney, A.A.Khan, A.Maheeh^arl, S.Anwar and U.Stiarma,
Ind.J .Teoh. , 22, 99-103 (1984) .
9 . M.Qureshl and S.A.Nabl, J.Tnorg.Nucl.Chem., 22 , 571 (1967) .
10, G.T.WeMl, t».R.Baxl, Tnd.J.Teotinol., 1 6 ( 5 ) , 204-6 (1978) ,
11 , N,E.Topp and fC,W,Pepper, J ,Chc«,Soc, , 3299 ( I949 ) .
12 , N,n.Faniian, "Standard Methods of Chemloal Analyala**, VT Edn. ,
Vol , 1 , fl,Yan Nostrand Company, I n c . , Princeton, Tfow Jersey
(1963) .
13 , A.T.Togel, "Textbook of Quantitative Inorganic Analyela",
TT rev.Edn, Clay (The Chancer P r e s s ) , Bungay (1978) ,
14, P,l>,Snell and G,T,Snel l , Color lvetr lo Methods of Analys i s" ,
IIT Bdn. , Yol . IT, p. 438, B-Yan Nostrand Company, I n c . ,
Princeton, !fsw York (1959) .
39
15. B.B.Sand«ll, "Colorinmtrlo DaterainatIon of Traces of Netala**,
Vol. I l l t P» 282, Inter Science publlaherfi, H»w York (1959)•
16. F.W.Snell and C.T.Snell, "ColorIwetrio Methoffs of Analytrla**,
•ol» IIAt p« <J99» ''^.•an Nostrand Company, Inc . , Princeton,
New Jersey (1959)»
17. C.N.Rellley, R.W.Schmlrt an«1 Pawzys, J.Chem.Educ., ^6, 555
(1959).
18. Berardl l l i , P.C.Galll, A.Lagenestra, M.A.MasKnool and
K.G.Varahney, J.Cheia.8oo. naltons Transactions (In Press) .
G H A P T E B - I I I
QUANT ITATIW SEPAflATlON OP IRON FROM SOME
MOLTIVITAMIN-HULTIMINERAL FQHMDLATIONS
USING ZIRCONICM(IV) ARSBNOPHOSHUtE COLUMNS
40
B«t«mlBatloii of nifMral • lenente In oomMretal
{thamaoeuttoals lias bean a eab.l«ot «f seiraral Invaatlgatlona
using different analytical teobnlfiuaff (1-S)« In wost of the
aatermlnation methods, severe Interferences are oaased due to
presence of certain tons 8n< separations are thus necessary
prior to the tfeteralnatlon* Korkisoh et a l , reported (9) that
in the determination of netal ions in nultivitainin preparations
by atomic absorption spectrophotometry, iron interferes seriously
which was separated on Bowex 1X8 anion exchange re a in prior to
the determination* This chapter snomariKes a taethod to separate
iron frors other taetal lone in some mttltivltamin-iBUltliiiinerel
fortBulations using zirconiuto(XT) areenophof<phate as a cation
exchanger, which hee ear l i er shown (10) good ion-exohange
ch a rac t e r 1 st Ic s •
41
BXFBRIMEliTAL
gACEHTS ASP CHEMICALS
The stroonyl chlorld* and trltodium orthophotphate nmd
In th i s study were the B«^,H, (Eogland) products whlls disodlnn
arsenate was an E.Merck ('Darmstadt) product. Other reagents and
ohenlcals vere of analsrtloel grade.
SYNTHESTS OF TOE lON«EXCnANGB MATERIAL
Zlroonlais(IV) arsenophosphate was prepared hy the method
reported earl ier (10) as followst
Aqueous eolutlone (0«05 N) of zlroonyl chloride, dlsodlum
arsenate and trlsodlum orthophoepheto were mixed In equal volurees
and the pB of the nlxture was flsEed In the range O*! by adding
n i t r i c acid with ccmstant s t irr ing . The gel thus obtained was kept
at room temperature (30 C) OTemlght and f i l tered , washed with
demlnerallxed water (DMV), and dried at 40 C In an a ir ovea. The
drle'^ product was cracked In IWW to obtain granules which were
converted Into the R form with IM HN0»« It was heated at SMX) C
for 1 hour before using for column operations as the phase (<<->SAp)
obtained by th i s treatment Is hlp^hly selectlire for Iron (lO).
SEPARATIONS
Synthetic Mixtures
Two grams of the 6o«»100 mesh slsed part ic les of the exchanger
42
(cX,*IAP) in B^ form w«r» U8«d for eoluim oporatlonf In « glass
tubo having an intamal dlaiaetar of --'O.S oa, Tha oolamn wan
waahaA thoz^ughly with WX and tha Mixture ( i n l ) waa loaded on i t ,
Maintaining a flow rata of '-^O.l ml/nin. Tha alution of the natal
ions other than Fa(TT) was done hy O.OlM HNDj. Fa(11) was than
elutad out with %M HNO. with the alMultaneoua regeneration of the
column. The rate of flow for the elution wa« kept'^^l nil/«in«
The netal ions in the effluents were d«»temined qaantitatlTely by
ET»TA t i trat ion exoe{>t S(T)i, which was detertnined floiBe>photomet~
r l c a l l y . The sal ient features of the separation of Pe(TT) fro«
other metol ions in aoiae sjmthetio mixtures are susmarized in
Table-VTI.
Capaules and Tablats
One capsule/tablet was boiled with 3 ml of oono. HCl and
50 nl of IMW vaa added. After f i l t er ing through a Vhatnan No« %
f i l t e r paper the solution was nade upto 100 nl with DMV, One nl
of thia solution was evaporated to almost dryness and the raaidue
was taken in ^^ 1 nl of T)^« It was than loaded on the eolunn of
the ion exchanger by the saiM» procedure as described for the
synthetic nixturaa. All the netal ions except iron were elutad
out with O.OIM HNO- (nax.vol. required ~ 150 n l ) . Iron was f ina l ly
removed with 4M HMO- (nax.vol, raquired ^ 5 0 nl) and datamined
quantitatively by EDTA t i trat ion at ffl 4 and ualng Cu-pAN indicator.
The raaulta are sunnarisad In Table-VTIT.
43
PISCPSSION
nM Miln feature of th«8« studies has been the separation
of Iron from other minerals In some multlirltamln-multlmineral
fomulatlons on an Inorganic ion exohanirer* fhe iMthod i s
applicable to the synthetic mixturee (Table-TII) ee well as to
the dntft samples (Table-VITT) and i s based on the high se l ec t iv i ty
of zirconiuiR(IV) areenophospliate for iron. As the results show
the method appeara t o be accurate and precise with a coeff icient
of variance <. 2 . It has i l lustrated the use of zirconlu»<IV)
arsenophosphate in the analysis of pharmaceutical products.
44
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46
BBFBIIKNCES
1* M«l,A«Cooper, J.Ballaatine and A,l)«Woolfron, J.Fham,
Pharmaool., 21,* *05 (1979).
2 . B.StankoTlo, M.l^uganAsle end M.Jeliklo, Ptaamaxle, ^S.* ^^^
(1977).
3 . flanlel J .J ,Sul l ivan, Aasoc, off Anal.Chem,, 22., 1156 (1976).
4 . Hanlel J.J.Sullliran, ABBOC, aff Anal.Chem,, 60, 1350 (1977).
5. S.W,Bl«liara anfl P.M.El-SammRn, Mloroohefli.J., 22, 4*2 (1977).
6. F.Pellcrln and J.P.Ctoulle, Ana.Pharm.Pr,, 21 , 189 (1977).
7. Penttl O.Koaonea, Anne<^arle Saloaen anrf Annalllsa Klevmlnen,
Flnn.Cben.Latt., 4., 136 (1978).
8 . S,A,Ii)l«R:inawy, M.T,Wala«h, M.r.Abon-Bakr and T.Z.Blala,
J.Virag nea., 2» 151 (1975).
9 . J.Korklsch and H.Hucbner, yilcroobliit.Acta, £ , 311 (1976).
10. K.G.Varshney, fC.Varahnay and S.Agrawal, Sep.Sol.TaotiBol.,
18, 905 (1983).