- Email: [email protected]
The ion-exchange behaviour of beryllium ammonium phosphate towards sodium and potassium ions in solution
•" l t l ¢ l [ ~ l l l
SHORT
(I ( IIItrll¢tl ¢|1
t{I
[ Iscvtcr P u b h , t h m g C o m p a n y , Am,~terd,im P r i n t e d m I lit. Nt.lhcrl,md,,
454
COMMUNICATION
T h e i o n - e x c h a n g e behaviour o f beryllium a m m o n i u m phosphate towards sodium and potabsium ions in solution p, K IYER, K R KRISilNAMO(_)II. FitY,md M SANKAP, I)AS ,4 nttlyttc ttl Dtt~P.ton, Bhahha A tomtt Reseto t h Centre, "[i ombav, Bomba ~'-85 (imha)
(Rect:wed 20th J,tnu,try 1972)
The precipitation of b e r y l h u m a m m o n i u m p h o s p h a t e finds a p p h c a t l o n m m a n y p r o c e d u r e s for the d e t e r m i n a t i o n o f b e r y l h u m t - "~ H o w e v e r , it h a s b e e n o b s e r v e d t h a t s o d i u m a n d p o t a s s i u m ions a r e z n c o r p o r a t e d m t h e p r e c i p i t a t e w h e n these Ions a r e p r e s e n t d u r i n g p l e c l p l t a t l o n {'. H e n c e , ~t was o f I n t e r e s t to e x a m i n e w h e t h e r b e r y l h u m a m m o m u m p h o s p h a t e e x c h a n g e d t h e s e i o n s m s o h m o n . T h e r e s u l t s of the s t u d y a r e r e p o r t e d m this p a p e r . T h e ion-exchange b c h a v l o u r of b e r y l h u m a m m o m u m p h o s p h a t e prepared by h o m o g e n e o u s p r e c l p l t a t l o n b y t r l c h l o r o a c e t l c a o d h y d r o l y s i s °'7, a n d a l s o by c o n v e n t l o n a l p r e c i p i t a t i o n 2"3 w a s s t u d i e d b y e l u t s o n e x p e r i m e n t s , w t t h b a t c h e q m h b r a t l o n , e q t H h b r l u m values w e r e n o t a t t a i n e d e v e n alter s h a k i n g f o r 24 h a n d the rate o f e x c h a n g e was slow Expertmental Preparatton
bv homo qeneous prectpttatum. HydrolyMs of trlchioroacetic acid as u s e d p l e v l o u s l y 7, was a d o p t e d f o r this p r e c i p i t a t i o n . Sufficient d l a m m o m u m h y d r o g e n p h o s p h a t e was ~ldded t o give a n mltl.'d P O 4 . Be r a t i o o f 5" 1. T h e p r e c i p i t a t e a f t e r d i g e s t i o n for 2 h o11 a w a t e r b a t h h a d t h e r a t i o o f B e . N H , , P O 4 as 1 "0.6"1 ( T y p e A), w h i l e a n o t h e l s a m p l e , o b t a i n e d a f t e r d t g e s t l o n oveI n i g h t at r o o m t e m p e r a t u r e , g a v e t h e r a t i o I ' 1 1 ( T y p e B) Preparatton h V cont,entionai prectlntatton The method recommended by Hure et al. 2 w a s f o l l o w e d , the s t a r t i n g P O 4 :Be r a t i o b e i n g 5 ' 1. A n a l y s i s o f t h t s p r e c i p i t a t e , a f t e r d i g e s t i o n for 2 h on a w a t e r b a t h , g a v e a ratio o f 1 '1:1 for B e ' N H 4 P O a , h e n c e no overnight digestion was needed. E l u t w n . B e c a u s e o f t h e fine g r a m stze, a p p r e c i a b l e f l o w r a t e s w e r e n o t a t t a i n e d w i t h c o l u m n s p a c k e d with b e r y l l i u m a m m o n i u m p h o s p h a t e . T h e m a t e r m l w a s therefore s u p p o r t e d o n cellulose p o w d e r ( W h a t m a n c h r o m a t o g r a p h i c g r a d e ) . W h e n c e l l u l o s e w a s m i x e d with b e r y l h u m a m m o n i u m p h o s p h a t e a f t e r p r e c i p i t a t i o n , segreg a t i o n o c c u r r e d m the c o l u m n a f t e r l o a d m g . A m o r e u n i f o r m d i s t r i b u t i o n w a s o b t a i n e d w h e n c e l l u l o s e p o w d e r w a s a d d e d to t h e c l e a r s o l u t i o n b e f o r e p r e c i p i t a t i o n . In g e n e r a l , 1 m m o l e o f b e r y l h u m as BeSO,~ a n d 5 m m o l e s o f d i a m m o m u r n h y d r o g e n p h o s p h a t e w e r e u s e d for t h e p r e p a r a t t o n m t h e p r e s e n c e of 1 g o f cellulose p o w d e r . T h e c o l u m n u s e d w a s 12 c m l o n g a n d o f 8 m m i n t e r n a l d i a m e t e r , p r o v i d e d w i t h a s e p a r a t i n g funnel a t t h e t o p a n d a s t o p c o c k at the b o t t o m t o c o n t r o l t h e flow. Anal Clmn Acta, 60 (1972)
SHORT COMMUNtCATiON
455
A f t e r t h e s l u r r y h a d b e e n t r a n s f e r r e d t o t h e c o l u m n , it w a s w a s h e d f r e e o f phosphate and ammomum ions with distilled water ; 1 M sodium chloride was then p a s s e d t h r o u g h t h e c o l u m n a t t h e r a t e o f 0 . 2 m l m l n - 1 a n d 4 f r a c t i o n s e a c h o f 4 ml were collected. Since the rate of exchange was slow, elutlon was carried out for a p e r i o d o f f o u r d a y s . T h e '~elutlon c u r v e s " s h o w n in F i g . 1 r e p r e s e n t t h e a m o u n t e x c h a n g e d o v e r m g h t a n d e l u t e d o u t o f t h e c o l u m n t h e n e x t d a y ( e x c e p t i n g t h e first day on which elutton was started) The column was washed free of sodium ions and the reverse exchange ofsodtum for ammomum ions was studied with 1 M ammonium chloride as the eluant. A similar elutlon was carried out with 1 M potassium chloride instead of sod]um chloride on a separate column. The ammomum m n c o n c e n t r a t i o n in t h e f r a c t i o n s w a s d e t e r m i n e d s p e c t r o photometrically with Nessler's reagent s and the alkah ions by flame photometry. DI,SC'II,$MOI1
F i g u r e s 1 a n d 2 s h o w t h e e x c h a n g e c u r v e s for N H ~ - N a + and NH~-K + on beryllium ammonium p h o s p h a t e , T a b l e s l ~ m d II s h o w t h e m l l h m o l e s o f i o n s ex010
,
3o
1
CONVENTIONAL PRECIPITATION O 08
m
HOMO~NEOUS PRECIPITATION (TYPE B)
o m
E "-" 0
C~
06 m
% ' 0 0~ Z
0 02
0 00
3 Ist
F~g
"~
5
3 5 2rid cloy FRAC1 ION NO
doy
1 Fxch,mge
curves
00~
m
for NH~-
3 5 l s ! day
1 3 5 2rid dcly F R A C T I O N NO
3 5 3 r d doy
Na 4 exchange
HOMOGENEOUS
CONVENTIONAL PRECIPI TATION
E E o
3 5 3td doy
o 02
UJ Z
0 O0 -1.....1
.
.
.
3 5 Is! doy
I-7 1
. 3 5 2nd d a y
~
, I
3
5
3rd doy
2
Exchange
curves
for NH,~-K
Anal Cllml. Acts, 6 0 ( 1 9 7 2 )
3 5 day
3 5 2rid d a y F R A C T I O N NO
F R A C T I O N NO
Fig
1st
+ exchange
1
3 5 3¢d day
456
Stt ORT COM M UN ICATION
c h a n g e d each day It is clear that m o s t o f the e x c h a n g e o c c u r r e d w h e n the e l u a n t w a s m c o n t a c t w i t h the p r e c i p i t a t e o v e r n i g h t F o r the p r e c i p i t a t e s o b t a i n e d f r o m h o m o g e n e o u s s o l u t i o n , T y p e B e x c h a n g e d m o r e r a p i d l y w i t h s o d i u m t h a n T y p e A, a n d b o t h o f t h e m e x c h a n g e d faster t h a n the c o n v e n t i o n a l l y p r e c i p i t a t e d salt. T h e e x c h a n g e o f s o d m m m T y p e B w a s reversible a n d s t o l c h l o m e t n c w i t h i n e x p e m m e n t a i error In the case o f p o t a s M u m , the extent o f e x c h a n g e w a s m u c h less a n d the reverse e x c h a n g e w a s s l o w e r t h a n that o f s o d i u m T h e s e o b s e r v a t i o n s m d i c a t e that the b e r y l h u m a m m o m u m phosphate obt a i n e d b y h o m o g e n e o u s p r e c i p i t a t i o n is m u c h m i n e a m e n a b l e to t h e e x c h a n g e o f a l k a h m e t a l ions t h a n that o b t a i n e d b y c o n v e n t i o n a l p r e c i p m t t l o n T h e differences b e t w e e n these t w o types o f p r e c l p m l t e m a y be a t t r i b u t e d to v a r i o u s p a r a m e t e r s , s u c h as p o r e .size, crystal c o n f i g u r a t i o n , e t e , g o v e r n i n g the e x c h a n g e T h e sigml'Jcant difference o b s e r v e d na the c a s e o f b e r y l l i u m a m m o m u m p h o s p h a t e o b t a i n e d by h y d r o l y s i s but c o n t a i n i n g s t o i c h l o m c t n c a n d s u b - s t o l c h l o m e t r l c a m o u n t s o f a m m o nmrn ions, indicates that the h y d r o g e n b o u n d to the B e P O , , - m a t r i x h a s a s i g m f i c a n t effect. TABI I I N I l e . N,! L X C I I A N G E A N D
N,I-NtI., i'.XCtlANGF.
ON ltFRYLLIUM
AMMONIUM
F'll O",I'tlA
It
("I lie v,iltlek glVela dlC lil inlllOlC~,) it'( tl h v d r o l V',1% lll/Jlthfld .
.
.
.
.
.
C'()III'('III I o l l t l l
pit'( IpIIUIIoII
.
7 Vpe A Nil2
Ist d a y 2nd day 3rd day 4th d a y
.
.
.
eluted
0 125 0 131 0 156 0096
Tot,,l .
Fvpe B
0 508 .
.
.
TABLE
.
.
.
.
.
.
.
N,t ~ elute,l
Nil2
0 141 0 123 0023 0023
0 0 0 0
0 "~10
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
eluted
Na'
cluted
NIl., ~ eluted
Nu'
114 308 II 1 1~0
(1533 0092 0038 I)021
0046 0 184 0(198 0072
0070 I)047 0(.119 0015
0 663
0 684
0 400
O !5I
.
II
NtI.,--K EXCHANGE A N D K NI-I.~ I ' X C H A N G E (The v a l u c s ( w e n arc m m m o l c s )
.
.
.
BI:RYLLIUM
.
.
.
AMMONIUM
I~ilOSPllA'IE
(. ollI c'tltlon~ll pt c,e t p l t a t l o l l
Type A .
ON
lll'dlr~lvsts method
TCA
Type B .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Nll.~ eluted
K + eluted
NII,~ eluted
K + eluted
NH.~ eluted
1st d a y 2nd day 3rd day 4th day
0047 0044 0 020 0 038
0050 0038 0 009 0013
0 0 0 0
037 041 021 010
0032 0012 0 003 0002
0 0 0 0
Total
0 147
0 110
0 109
0049
0022
Anul
,,lut,,,l
Chtm Acta, 60 ( 1 9 7 2 )
005 005 003 009
K + eluted
0 0 0 0
008 002 002 O01
0013
SHORT COMMUNICATION
457
T h e exchange pattern o b s e r v e d m this study defimtely shows that alkah metal i o n s h a v e a d e t r i m e n t a l effect o n t h e g r a v l m e t n c r e s u l t s o b t a i n e d b y i g n i t i n g t h e p r e c i p i t a t e to B e 2 P 2 0 7 . R e p r e c l p l t a t t o n has been r e c o m m e n d e d m the case of c o n v e n t i o n a l p r e c i p i t a t i o n , to m i n i m i z e c o n t a m i n a t i o n b y the a l k a h Ion f r o m the flux ( N a 2 C O 3, N a F , etc ) u s e d to o p e n u p t h e ore s a m p l e s O t h e r w m e , the i g m t e d r e M d u e h a s the a p p e a r a n c e o f a fused m a s s a n d s h o w s t h e p r e s e n c e o f s o d i u m '~'t° T h e c o m p a r a t i v e e a s e w i t h w h i c h s o d i u m xon,, e x c h a n g e f o r a m m o n i u m i o n s in t h e h o m o g e n e o u s l y precspltated c o m p o u n d explains why s]mdar interference was not o b s e r v e d w h e n p r e c i p i t a t i o n w a s c a r n e d o u t m the p r e s e n c e o f s o d s u m i o n s 7. T h e i n t e r f e r e n c e o f p o t a s s m m i o n s w a s o b s e r v e d in b o t h c a s e s w h e n p r e c i p i t a t i o n o f b e r y l h u m a m m o m u m p h o s p h a t e w a s d o n e in t h e p r e s e n c e o f p o t a s s i u m ions 7 , this c o r r e s p o n d s t o t h e e x c h a n g e p a t t e r n s h o w n in T a b l e II a n d F~g. 2 W h d e It is d i f f i c u l t to r e p l a c e a m m o n m m w t t h p o t a s s i u m sons o n b e r y l h u m a m m o n t u m p h o s p h a t e , ~t ~s r e l a t i v e l y e a s y t o p s e p a r e a c o m p o u n d o f t h e t y p e B e K , H ~ _ ,~PO,~ ( w h e r e x ~s as h~gh a s 0 8) b y t n c h l o r o a c e t l c acid h y d r o l y M s 7 H e n c e , t h e s m a l l e r u p t a k e o f p o t a s s i u m ~on o b s e r v e d h e r e d o e s n o t n e c e s s a r i l y i n d i c a t e a l o w e r p r e f e r e n c e for t h i s son, b u t m a y b e a t t r i b u t e d to a s l o w r a t e o f e x c h a n g e so t h a t e q u d t b r ~ u m ~s n o t readily attained R I11- I : I ~ I ' N (
1
R AIroldt. ,Itm C l u m , 44 (1954) 127 J l l u r c . M K r e m c r a n d k LeBcqutcrcr. Anal Claim A~ta. 7(1952) 37 M S a n k a r l)a,, ,tnd V T Ath,tv,tle. /ltlal ¢'hun Actu, 12 (1955)6 M Stmdares,tn a n d M S a n k a r l')a,,. Anal, st. 80 (1955) 696 A J P a t k a r , m d M S Varde. lt~dta,.I C h e p ~ , 2 ( 1 9 6 6 ) 123 K I~. Krl,,l'mamoortlay. M S~ "[hesls. B o m b a y Untverslty, 1966 K I~, KrP, h n a m o o r t h y , t n d R K l y e r . / l u a l Chtm Aeta. 47(1969) 333 S Ii Y u e n a n d A G PolI,Lrd, J Set l . o o d A q r t c . 3 ( 1 9 5 2 ) 4 4 1 G It Smith. u n p u b h , , h e d o b s e r v a t i o n t l I) A Fvcrcsl. Chemlstr~ o/ Bep vlhum, I:l,,cvler, A m s t e r d a m , 1964. p 119 10 A J Patk,tr. per,,onal commtml~,atlon from thl~ h t b o r a t o r y I 2 3 4 5 6 7 g 9
Anal Chm~ Actu, 6 0 ( 1 9 7 2 )
SHORT
(I ( IIItrll¢tl ¢|1
t{I
[ Iscvtcr P u b h , t h m g C o m p a n y , Am,~terd,im P r i n t e d m I lit. Nt.lhcrl,md,,
454
COMMUNICATION
T h e i o n - e x c h a n g e behaviour o f beryllium a m m o n i u m phosphate towards sodium and potabsium ions in solution p, K IYER, K R KRISilNAMO(_)II. FitY,md M SANKAP, I)AS ,4 nttlyttc ttl Dtt~P.ton, Bhahha A tomtt Reseto t h Centre, "[i ombav, Bomba ~'-85 (imha)
(Rect:wed 20th J,tnu,try 1972)
The precipitation of b e r y l h u m a m m o n i u m p h o s p h a t e finds a p p h c a t l o n m m a n y p r o c e d u r e s for the d e t e r m i n a t i o n o f b e r y l h u m t - "~ H o w e v e r , it h a s b e e n o b s e r v e d t h a t s o d i u m a n d p o t a s s i u m ions a r e z n c o r p o r a t e d m t h e p r e c i p i t a t e w h e n these Ions a r e p r e s e n t d u r i n g p l e c l p l t a t l o n {'. H e n c e , ~t was o f I n t e r e s t to e x a m i n e w h e t h e r b e r y l h u m a m m o m u m p h o s p h a t e e x c h a n g e d t h e s e i o n s m s o h m o n . T h e r e s u l t s of the s t u d y a r e r e p o r t e d m this p a p e r . T h e ion-exchange b c h a v l o u r of b e r y l h u m a m m o m u m p h o s p h a t e prepared by h o m o g e n e o u s p r e c l p l t a t l o n b y t r l c h l o r o a c e t l c a o d h y d r o l y s i s °'7, a n d a l s o by c o n v e n t l o n a l p r e c i p i t a t i o n 2"3 w a s s t u d i e d b y e l u t s o n e x p e r i m e n t s , w t t h b a t c h e q m h b r a t l o n , e q t H h b r l u m values w e r e n o t a t t a i n e d e v e n alter s h a k i n g f o r 24 h a n d the rate o f e x c h a n g e was slow Expertmental Preparatton
bv homo qeneous prectpttatum. HydrolyMs of trlchioroacetic acid as u s e d p l e v l o u s l y 7, was a d o p t e d f o r this p r e c i p i t a t i o n . Sufficient d l a m m o m u m h y d r o g e n p h o s p h a t e was ~ldded t o give a n mltl.'d P O 4 . Be r a t i o o f 5" 1. T h e p r e c i p i t a t e a f t e r d i g e s t i o n for 2 h o11 a w a t e r b a t h h a d t h e r a t i o o f B e . N H , , P O 4 as 1 "0.6"1 ( T y p e A), w h i l e a n o t h e l s a m p l e , o b t a i n e d a f t e r d t g e s t l o n oveI n i g h t at r o o m t e m p e r a t u r e , g a v e t h e r a t i o I ' 1 1 ( T y p e B) Preparatton h V cont,entionai prectlntatton The method recommended by Hure et al. 2 w a s f o l l o w e d , the s t a r t i n g P O 4 :Be r a t i o b e i n g 5 ' 1. A n a l y s i s o f t h t s p r e c i p i t a t e , a f t e r d i g e s t i o n for 2 h on a w a t e r b a t h , g a v e a ratio o f 1 '1:1 for B e ' N H 4 P O a , h e n c e no overnight digestion was needed. E l u t w n . B e c a u s e o f t h e fine g r a m stze, a p p r e c i a b l e f l o w r a t e s w e r e n o t a t t a i n e d w i t h c o l u m n s p a c k e d with b e r y l l i u m a m m o n i u m p h o s p h a t e . T h e m a t e r m l w a s therefore s u p p o r t e d o n cellulose p o w d e r ( W h a t m a n c h r o m a t o g r a p h i c g r a d e ) . W h e n c e l l u l o s e w a s m i x e d with b e r y l h u m a m m o n i u m p h o s p h a t e a f t e r p r e c i p i t a t i o n , segreg a t i o n o c c u r r e d m the c o l u m n a f t e r l o a d m g . A m o r e u n i f o r m d i s t r i b u t i o n w a s o b t a i n e d w h e n c e l l u l o s e p o w d e r w a s a d d e d to t h e c l e a r s o l u t i o n b e f o r e p r e c i p i t a t i o n . In g e n e r a l , 1 m m o l e o f b e r y l h u m as BeSO,~ a n d 5 m m o l e s o f d i a m m o m u r n h y d r o g e n p h o s p h a t e w e r e u s e d for t h e p r e p a r a t t o n m t h e p r e s e n c e of 1 g o f cellulose p o w d e r . T h e c o l u m n u s e d w a s 12 c m l o n g a n d o f 8 m m i n t e r n a l d i a m e t e r , p r o v i d e d w i t h a s e p a r a t i n g funnel a t t h e t o p a n d a s t o p c o c k at the b o t t o m t o c o n t r o l t h e flow. Anal Clmn Acta, 60 (1972)
SHORT COMMUNtCATiON
455
A f t e r t h e s l u r r y h a d b e e n t r a n s f e r r e d t o t h e c o l u m n , it w a s w a s h e d f r e e o f phosphate and ammomum ions with distilled water ; 1 M sodium chloride was then p a s s e d t h r o u g h t h e c o l u m n a t t h e r a t e o f 0 . 2 m l m l n - 1 a n d 4 f r a c t i o n s e a c h o f 4 ml were collected. Since the rate of exchange was slow, elutlon was carried out for a p e r i o d o f f o u r d a y s . T h e '~elutlon c u r v e s " s h o w n in F i g . 1 r e p r e s e n t t h e a m o u n t e x c h a n g e d o v e r m g h t a n d e l u t e d o u t o f t h e c o l u m n t h e n e x t d a y ( e x c e p t i n g t h e first day on which elutton was started) The column was washed free of sodium ions and the reverse exchange ofsodtum for ammomum ions was studied with 1 M ammonium chloride as the eluant. A similar elutlon was carried out with 1 M potassium chloride instead of sod]um chloride on a separate column. The ammomum m n c o n c e n t r a t i o n in t h e f r a c t i o n s w a s d e t e r m i n e d s p e c t r o photometrically with Nessler's reagent s and the alkah ions by flame photometry. DI,SC'II,$MOI1
F i g u r e s 1 a n d 2 s h o w t h e e x c h a n g e c u r v e s for N H ~ - N a + and NH~-K + on beryllium ammonium p h o s p h a t e , T a b l e s l ~ m d II s h o w t h e m l l h m o l e s o f i o n s ex010
,
3o
1
CONVENTIONAL PRECIPITATION O 08
m
HOMO~NEOUS PRECIPITATION (TYPE B)
o m
E "-" 0
C~
06 m
% ' 0 0~ Z
0 02
0 00
3 Ist
F~g
"~
5
3 5 2rid cloy FRAC1 ION NO
doy
1 Fxch,mge
curves
00~
m
for NH~-
3 5 l s ! day
1 3 5 2rid dcly F R A C T I O N NO
3 5 3 r d doy
Na 4 exchange
HOMOGENEOUS
CONVENTIONAL PRECIPI TATION
E E o
3 5 3td doy
o 02
UJ Z
0 O0 -1.....1
.
.
.
3 5 Is! doy
I-7 1
. 3 5 2nd d a y
~
, I
3
5
3rd doy
2
Exchange
curves
for NH,~-K
Anal Cllml. Acts, 6 0 ( 1 9 7 2 )
3 5 day
3 5 2rid d a y F R A C T I O N NO
F R A C T I O N NO
Fig
1st
+ exchange
1
3 5 3¢d day
456
Stt ORT COM M UN ICATION
c h a n g e d each day It is clear that m o s t o f the e x c h a n g e o c c u r r e d w h e n the e l u a n t w a s m c o n t a c t w i t h the p r e c i p i t a t e o v e r n i g h t F o r the p r e c i p i t a t e s o b t a i n e d f r o m h o m o g e n e o u s s o l u t i o n , T y p e B e x c h a n g e d m o r e r a p i d l y w i t h s o d i u m t h a n T y p e A, a n d b o t h o f t h e m e x c h a n g e d faster t h a n the c o n v e n t i o n a l l y p r e c i p i t a t e d salt. T h e e x c h a n g e o f s o d m m m T y p e B w a s reversible a n d s t o l c h l o m e t n c w i t h i n e x p e m m e n t a i error In the case o f p o t a s M u m , the extent o f e x c h a n g e w a s m u c h less a n d the reverse e x c h a n g e w a s s l o w e r t h a n that o f s o d i u m T h e s e o b s e r v a t i o n s m d i c a t e that the b e r y l h u m a m m o m u m phosphate obt a i n e d b y h o m o g e n e o u s p r e c i p i t a t i o n is m u c h m i n e a m e n a b l e to t h e e x c h a n g e o f a l k a h m e t a l ions t h a n that o b t a i n e d b y c o n v e n t i o n a l p r e c i p m t t l o n T h e differences b e t w e e n these t w o types o f p r e c l p m l t e m a y be a t t r i b u t e d to v a r i o u s p a r a m e t e r s , s u c h as p o r e .size, crystal c o n f i g u r a t i o n , e t e , g o v e r n i n g the e x c h a n g e T h e sigml'Jcant difference o b s e r v e d na the c a s e o f b e r y l l i u m a m m o m u m p h o s p h a t e o b t a i n e d by h y d r o l y s i s but c o n t a i n i n g s t o i c h l o m c t n c a n d s u b - s t o l c h l o m e t r l c a m o u n t s o f a m m o nmrn ions, indicates that the h y d r o g e n b o u n d to the B e P O , , - m a t r i x h a s a s i g m f i c a n t effect. TABI I I N I l e . N,! L X C I I A N G E A N D
N,I-NtI., i'.XCtlANGF.
ON ltFRYLLIUM
AMMONIUM
F'll O",I'tlA
It
("I lie v,iltlek glVela dlC lil inlllOlC~,) it'( tl h v d r o l V',1% lll/Jlthfld .
.
.
.
.
.
C'()III'('III I o l l t l l
pit'( IpIIUIIoII
.
7 Vpe A Nil2
Ist d a y 2nd day 3rd day 4th d a y
.
.
.
eluted
0 125 0 131 0 156 0096
Tot,,l .
Fvpe B
0 508 .
.
.
TABLE
.
.
.
.
.
.
.
N,t ~ elute,l
Nil2
0 141 0 123 0023 0023
0 0 0 0
0 "~10
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
eluted
Na'
cluted
NIl., ~ eluted
Nu'
114 308 II 1 1~0
(1533 0092 0038 I)021
0046 0 184 0(198 0072
0070 I)047 0(.119 0015
0 663
0 684
0 400
O !5I
.
II
NtI.,--K EXCHANGE A N D K NI-I.~ I ' X C H A N G E (The v a l u c s ( w e n arc m m m o l c s )
.
.
.
BI:RYLLIUM
.
.
.
AMMONIUM
I~ilOSPllA'IE
(. ollI c'tltlon~ll pt c,e t p l t a t l o l l
Type A .
ON
lll'dlr~lvsts method
TCA
Type B .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Nll.~ eluted
K + eluted
NII,~ eluted
K + eluted
NH.~ eluted
1st d a y 2nd day 3rd day 4th day
0047 0044 0 020 0 038
0050 0038 0 009 0013
0 0 0 0
037 041 021 010
0032 0012 0 003 0002
0 0 0 0
Total
0 147
0 110
0 109
0049
0022
Anul
,,lut,,,l
Chtm Acta, 60 ( 1 9 7 2 )
005 005 003 009
K + eluted
0 0 0 0
008 002 002 O01
0013
SHORT COMMUNICATION
457
T h e exchange pattern o b s e r v e d m this study defimtely shows that alkah metal i o n s h a v e a d e t r i m e n t a l effect o n t h e g r a v l m e t n c r e s u l t s o b t a i n e d b y i g n i t i n g t h e p r e c i p i t a t e to B e 2 P 2 0 7 . R e p r e c l p l t a t t o n has been r e c o m m e n d e d m the case of c o n v e n t i o n a l p r e c i p i t a t i o n , to m i n i m i z e c o n t a m i n a t i o n b y the a l k a h Ion f r o m the flux ( N a 2 C O 3, N a F , etc ) u s e d to o p e n u p t h e ore s a m p l e s O t h e r w m e , the i g m t e d r e M d u e h a s the a p p e a r a n c e o f a fused m a s s a n d s h o w s t h e p r e s e n c e o f s o d i u m '~'t° T h e c o m p a r a t i v e e a s e w i t h w h i c h s o d i u m xon,, e x c h a n g e f o r a m m o n i u m i o n s in t h e h o m o g e n e o u s l y precspltated c o m p o u n d explains why s]mdar interference was not o b s e r v e d w h e n p r e c i p i t a t i o n w a s c a r n e d o u t m the p r e s e n c e o f s o d s u m i o n s 7. T h e i n t e r f e r e n c e o f p o t a s s m m i o n s w a s o b s e r v e d in b o t h c a s e s w h e n p r e c i p i t a t i o n o f b e r y l h u m a m m o m u m p h o s p h a t e w a s d o n e in t h e p r e s e n c e o f p o t a s s i u m ions 7 , this c o r r e s p o n d s t o t h e e x c h a n g e p a t t e r n s h o w n in T a b l e II a n d F~g. 2 W h d e It is d i f f i c u l t to r e p l a c e a m m o n m m w t t h p o t a s s i u m sons o n b e r y l h u m a m m o n t u m p h o s p h a t e , ~t ~s r e l a t i v e l y e a s y t o p s e p a r e a c o m p o u n d o f t h e t y p e B e K , H ~ _ ,~PO,~ ( w h e r e x ~s as h~gh a s 0 8) b y t n c h l o r o a c e t l c acid h y d r o l y M s 7 H e n c e , t h e s m a l l e r u p t a k e o f p o t a s s i u m ~on o b s e r v e d h e r e d o e s n o t n e c e s s a r i l y i n d i c a t e a l o w e r p r e f e r e n c e for t h i s son, b u t m a y b e a t t r i b u t e d to a s l o w r a t e o f e x c h a n g e so t h a t e q u d t b r ~ u m ~s n o t readily attained R I11- I : I ~ I ' N (
1
R AIroldt. ,Itm C l u m , 44 (1954) 127 J l l u r c . M K r e m c r a n d k LeBcqutcrcr. Anal Claim A~ta. 7(1952) 37 M S a n k a r l)a,, ,tnd V T Ath,tv,tle. /ltlal ¢'hun Actu, 12 (1955)6 M Stmdares,tn a n d M S a n k a r l')a,,. Anal, st. 80 (1955) 696 A J P a t k a r , m d M S Varde. lt~dta,.I C h e p ~ , 2 ( 1 9 6 6 ) 123 K I~. Krl,,l'mamoortlay. M S~ "[hesls. B o m b a y Untverslty, 1966 K I~, KrP, h n a m o o r t h y , t n d R K l y e r . / l u a l Chtm Aeta. 47(1969) 333 S Ii Y u e n a n d A G PolI,Lrd, J Set l . o o d A q r t c . 3 ( 1 9 5 2 ) 4 4 1 G It Smith. u n p u b h , , h e d o b s e r v a t i o n t l I) A Fvcrcsl. Chemlstr~ o/ Bep vlhum, I:l,,cvler, A m s t e r d a m , 1964. p 119 10 A J Patk,tr. per,,onal commtml~,atlon from thl~ h t b o r a t o r y I 2 3 4 5 6 7 g 9
Anal Chm~ Actu, 6 0 ( 1 9 7 2 )