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四氟化铂PtF4 美国化学会ACS文献


solutions containing traces of metals can be passed through columns at high flow rate (100 ml per minute). To obtain reproducibility of results, chromatography on celluloses should be completed without interruptions and with the same flow rate; when it can be completed in 1 hour the influence of the temperature can be neglected. Possibilities also exist in organic chromatography, Celluloses with adsorbed metals are ligands for organic compounds such as amines, and some work on the separation of amines by ligand exchange on cellulosic supports treated with nickel has been attempted (15).
(15) K. Shimomura, L. Dickson, and H. F. Walton, Anal. Chim. Acta, 37, 102 (1967).

The information obtained during the present study is the necessary preliminary data required for further studying the chemical bonds of the metals collected on celluloses, either by infrared spectroscopy (16) or by recoil-less resonance fluorescence (Mossbauer effect). RECEIVED review May 5,1967. Accepted August 29,1967. for Study performed under Research Grant A-2507 (1 967) awarded by the National Research Council of Canada to R. A. A. Muzzarelli.
(16) R. G. Zhbankov, “Infrared Spectra of Cellulose and its Derivatives,’’ Congress Bureau-Plenum Press, New York, 1966.

Separation of Metal Ions on Stannic Phosphate tannic Tungstate Papers
Specific Separations of Au(lll), Hg(ll), Pt(lV), Mg(ll), Mo(VI), and Se(lV)
Mohsin Qureshi, Iqbal Akhtar and K. N. Mathur Chemical Laboratories, Department of Chemistry, Aligarh Muslim University, Aligarh, U P . , India

Mixed solvents have been effectively used to obtain analytically difficult separations of cations by chromatography on stannic phosphate and stannic tungstate papers. The separations achieved include:

(I)
(11)

Au+3, Sb+3, Sb+j, Pd+2, Hg+2, Pt+4, Asf3, K+, Rb+, Cs+, Mg+2, Z Y + ~Mo+~, , U02-2, Ag+, and Se+4 from numerous metal ions. A1+3-BetZ-Fe+3= Ti+LV+LFe+3; K-r-Cs+; Au+L Pd +Lpt+4; C +2-Cd -2; ; Sb+3-Sb+5; Ca+Z-Ba +2. Mg TZ-Sr+Z-Ba +2; UC)z+2-V~LMo+6; Ag +-Pt+LAu +3; Ag ---TI +-I n +3; Ce+3-Ce+4; Hg,+LHg +2; Pt+LAu +3lr+4; Pd+LAu+3; l ~ + ~ .

nonaqueous solvent systems on stannic phosphate (S.P.) and 4 6 metal ions in 45 solvent systems on stannic tungstate (S.T.) papers. As a result, a number of useful and interesting separations have been developed, and the earlier method for the preparation of stannic phosphate papers has been modified. EXPERIMENTAL

Apparatus. Glass jars, 20 by 5 cm, were used to develop paper strips 14 by 3 cm. Whatman No. 1 paper was used throughout the studies. Electrophoresis studies were performed on a horizontal type apparatus of Eastern Laboratory Instruments (India).
(1) G. Alberti, F. Dobici, and G. Grassini, J . Chromatog., 8, 103 (1962). (2) G. Alberti and G. Grassini, Zbid.,4, 83 (1960). (3) Zbid., p. 423. (4) M. Lederer, V. Moscatelli, and C. Padiglione, Zbid., 10, 456 (1961). (5) M. J. Nuiies Da Costa and M. A. S. Jeronimo, Zbid., 5, 456 (1961). (6) M. N. Sastri and A. P. Rao. Zbid.,9,250 (1962). (7) M. J. Nunes Da Costa and M. A. §. Jeronimo, Zbid., 5, 546 (1961). (8) Ying Bo Hai, Acta. Chim. Sinica,31,266 (1965). (9) G. Grassini and C . Padiglione, J . Chromatog., 13, 561 (1964). (10) M. J. Nunes Da Costa and M. A. S. Jeronimo, Zbid.,14, 555 (1964). (11) J. Krtil and V. Kourim, J . Inorg. Nucl. Chem., 12,367 (1960). (12) H. Schroeder,J. Chromatog., 4, 361 (1961). (13) §hi-Nien Shen, Zhu-Jiin Zhang, and Wuei-Ven Chang., Hua Hsuch Hsuch Pao, 30, 21 (1964). (14) Zhu-Jiin Zhang. Ying Bo-Hai, Tong-Zhen Bang, and ShihHien Shen, Acta. Chim. Sinica,31, 218 (1965). (15) M. Qureshi and S. Z. Qureshi, J . Chromatog., 22, 198 (1966). (16) J. Sherma, Talanta, 9,775 (1962). (17) J. Sherma and C. W. Cline, Ibid.,10, 787 (1963). CHEW, 690 (1964). 36, (18) J. Sherma, ANAL. (19) J. Sherma and C . W. Cline, Anal. Chim. Acta, 30, 139-47 (1964).

PAPERS IMPREGNATED with inorganic ion exchangers give cleaner and faster cation separations than untreated papers. The separations now depend not only on partition, but also on selectivities shown by the ion exchangers for various cations. Chromatography has therefore been performed on papers impregnated with zirconium phosphate (1-6), selenite (7), ammonium phosphomolybdate (3, 8), and tungstate (9-14). Papers impregnated with stannic phosphate (15) have also been used recently for some preliminary chromatographic work. Previous studies suffer from two limitations: (a) only pure inorganic solvents have been exclusively studied. Mixed solvent systems, which have shown very attractive possibilities on ion exchange columns, have not been adequately tested on ion exchange papers. (b) Numerous metal ions have not been chromatographed in a large number of solvent systems and hence the useful number of separations developed is not large. As far as we are aware, few separations of one cation from numerous metal ions using inorganic ion exchange papers have been reported in the literature, although Sherma and coworkers (16-19) have reported a number of specific separations on papers impregnated with organic ion exchangers. The present work was, therefore, undertaken to study systematically the behavior of 44 metal ions in 28 aqueous and
9 766
0

ANALYTICAL CHEMISTRY

~~~

Table I.

Separation of One Cation from Numerous Metal Ions on Stannic Phosphate Papers

Cation separated Auf3 ( I . 00) from 39 metal ions Sb+3 (0.90) from 35 metal ions Sb+6 (1 .OO) from 37 metal ions Pd+2 (0.25) from 39 metal ions Hgf2 (0.89) from 34 metal ions Pt+?(0.93) from 38 metal ions As+3 (0.46) or (0.71-0.22)from 36 metal ions Cs, Rb and K. (0.61, 0.62, & 0.65 respectively) from 35 metal ions

Solvent system n-Butanol-HC1-10 % NHK1 (7 :2 :1) n-Butanol-HC1-10 % NH4C1 (7:2 :1) n-Butanol-HNOs (8 :2) n-Butanol-HN03-H~O (8:l:l) 2N HC1-4N NaCl(1: 1)
0.05N NaCl-O.05N HC1 (1:l) 0.05- NaC1-O.05N HC1 (1:l) IN HNOa-2M (NH&HPO4 (1:l)

Ions likely to interfere Hgzf2,Hg+z, CU+',Sbfs, Sb+6,Zn+Z,Sn+l CU+, Hgz", Hg+', Sbf3, Sb+6,Zn+2, CdL2,and Ga+3 Hgz+2, A u + ~Mo", , and Sn+2 Hg+z, BifaB P 4 , P and probably Asf3 Mo+@, Pdt2, Cu+, Hgz+2,Zn+2, B F , Ag+, and Tl+ M o + ~Pdf2, A u + ~ , , and SeT4 K+, Se+4, Pd+2,M O + ~ , Au-3, Sb+t, and Hg+z Pd+2 Mo+@ Se+l aLd V+6
, 1

Time
3-3.5 hr 3-3.5 hr 2 . 5 hr and 5 . 5 hr for 15 cm 2.5-3 hr and 5-6 hr for 15 cm 35-40 rnin and 50 rnin for 16 cm 20-25 min and 45-50 rnin for 15 cm 20-25 min and 45-50 rnin for 15 cm 30-35 rnin and 50 rnin for 15 cm

Reagents, Chemicals and solvents were either E. Merck (Darmstadt) or British Drug House Analytical grade reagents. Table 1 . Separation of One Cation from Numerous Metal 1 Stannic chloride pentahydrate was a polland product. Ions on Stannic Tungstate Papers as Predicted by Rr values PHOSPHATE. Preparation of Ion Exchange Papers. STANNIC Metal ion Ions which A 0.50M solution of stannic chloride pentahydrate and a separated Solvent system interfere Time 1.OOM solution of diammonium hydrogen phosphate were prepared in water. Paper strips were first dipped in stannic Mg+a(0.78)from 1N Ammonium Ptf4, PdY2, Au+3, 20 min chloride solution for 3 seconds. Excess reagent was removed 37 cations formate K+, Rb+, Cs+, by placing the strips on a filter sheet for a little while. The and Ca+Z strips were then passed through diammonium hydrogen K+ (0.76) from 1N Ammonium PP4,Pdf2, A u + ~ 20 rnin phosphate for 5 seconds. The excess solution was similarly 37 cations formate Mg+Z,Rb+, Cs+, drained off and the strips were then dried at room temperaand CaS2 ture. After about 1-2 hours they were washed with water Rb+ (0.72) from 1N Ammonium W4,Pd+z, AuSa, 20 min twice. The wash water had a pH 5. The strips were again 37 cations formate Mg+2, K-, Csf, dried at room temperature and were used as such. and Caf2 STANNIC TUNGSTATE. 8.8% stannic chloride pentaA Cs" (0.61) from 1N Ammonium P P , Pd+z,A U + ~ , 20 rnin hydrate and 3.3 solution of sodium tungstate were prepared Mg+2,K+, Rb+, 36 cations for mat e and Ca+2 in distilled water. Paper strips were first passed through Zr+4(0.06) from Butanol f 50% Ag+, Hg2+2,BiL3, 2 hr stannic chloride solution for 3 to 5 seconds. The excess 25 cations "03 (1 :1) AS+^, Sb+', Cot', stannic chloride was removed by placing the strips on a filter Fef2,Fet3, Sei'', paper sheet. The strips were then dipped in hot sodium tungMo+@, Pt+4. Te+4, state solution for 5 seconds and the excess was drained off. Auia, Baf2,Thi-4, These strips were dried at 40"-45" C in an oven and then W 4 , RuA3, and washed with distilled water in order to remove any excess of Ir+4 the reagents. The strips were again dried at 40"-45" C and AuT3 (0.95) from Butanol 50% Hg+2 and U02+* 2 hr were used as such. 42 cations HNOa(7:3) TEST SOLUTIONS. 0.1M Solutions of chlorides, nitrates, or Hg+2(0.86) from Butanol 5 0 z A U +and UOzt2 ~ 2 hr sulfates of most of the cations were prepared in O.1M solution 42 cations " 1 (7:3) 0 of the corresponding acids. 0.1 solution of platinum was P P 4(0.96) from 0.1MAmmoMo+@, Se+4, U02+2 20 rnin prepared using platinum wire and dissolving it in aqua regia 42 cations nium carbonate and diluting. 0.1M Antimony and bismuth chlorides were Mo+~ (0.94) from 0.1M AmmoPt+4,Sef4,UOzf2 20 rnin prepared in 30% v/v and 3.7M HC1 solutions. 1 Solutions 42 cations nium carbonof gold and gallium chlorides were prepared in 4 M HCI ate solution. 1 % Niobium pentachloride was prepared in 10% UOZ+~ (0.52) Butanol 50% Ptf4,Pdi2, B P 3 , 2 hr tartaric acid. 0.1 M Sodium tungstate, sodium molybdate, Bef2,and AuA3 from 39 cations H N 0 3 (7:3) potassium chloride, cesium sulfate, and rubidium chloride Ag+ (0.90) from Pyridine 3- 1N H ~ Z + ~ , Cd+2, 75 rnin Hg+z, were prepared in distilled water. Selenium dioxide was dis32 cations acetic acid CU+~, NP2, Cr+a9 solved in water and made aIkaline with 1N KOH solution. (1:l) Zn+2, UOz+z, 0.1M tellurium solution was prepared by heating tellurium Pd+2, A d a , and metal in concentrated HN03 till the residue becomes white Ru+~ and then dissolving in 1N KOH. Ceric sulfate was prepared Set4 (0.92) from 0.1M AmmoAg+, Alfa, Cr+3, 20 min in 3.6N HaSO4. A 0.2M solution of stannous chloride was 33 cations nium tartrate Ce+a, Ce+4, M o + ~ , in 4M NH40H Ga+3, Z r 4 , K+, made in 6 N HC1. A 1 titanium solution was prepared by Rb+, Cs+, and dissolving titanic chloride in 12N HCl. Mercuric nitrate Pt+4 solution was prepared in 0.5147 nitric acid while Asz03 and Be(N03)2were dissolved in 12 HN03. A 0.1M solution of

+ +

+

VOL. 39,

NO. 14, DECEMBER 1967

8

1767

SbCls was prepared by oxidizing 0.2M SbC13solution in 30% HCl with concentrated HC1 and KC103. For Cu+, solution of C 2 2 was taken in an alcohol dioxane mixture containu1 ing some KI added for stabilization. Detectors. Yellow ammonium sulfide solution was used to detect Ag+, Pb+Z, Hg2+2,Hg+2, T1-, BP3, Cd-2, As+3, Sb+3, and Pd+2. A fresh solution of sodium cobaltinitrite was used to detect K+, RbT, and Cs-'. La+3, Ce-3, Ce+?, Y+3, Ga+3, Ca+2,In+3, %rT4,Th+4, and N b ~ were detected 5 with 0.1% alcoholic alizarine red S solution. Au+3, Pt+4, were located with the help of Se+4, TeT4, M o + ~ ,and SnCCHCl reagent. and Be+2 were detected with 1% alcoholic aluminon solution. Diphenyl carbazide detected Fe+3, U02+2, VA4,CuAz,and Ti+4 Mn+2, Z r 2 , and Cr'3. ~ were detected withK?Fe(CN)s. NP2,and C O +were detected with dimethyl glyoxime and a-nitroso-8-naphthol. BaT2and Sr+2were located with the help of 5x water solution of sodium rhodizonate. Mg+2 was detected with quinalizarine. Ru+~ was detected by dipping the strips in 2N HCl solution of thiouria and heating. Rhodamine B was used to detect Sb+5. Rubeanic acid was used to detect Cu+l. Cd+2 was located with the help of cadion 2B. Procedure. Thin glass capillaries were used to spot the test solutions. The chromatograms were conditioned for 10

to 15 minutes and then the solvent was allowed t o ascend 11 cm on paper unless otherwise mentioned. The time of development has been specified with each solvent. For compact zones only RP value is given which is usually a mean of two
values. In case there is some spreading of the zones, the front ( R L ) and rear limits (XT)of the zones are given in parentheses. Thus Fef3 (0.62) means a compact spot of Fe+3 with an R p of 0.62 and Pt+? (0.20-0.00) means that the Pt+? spot tails and its RL is 0.20 and Rr is 0.00.
RESULTS

A very large number of separations have been developed on stannic phosphate and stannic tungstate papers, The separations have been described under two heads : separation of one cation from numerous metal ions and separations practically achieved on the two types of papers. Separation of One Cation from Numerous Metal Ions. The selectivity shown by these ion exchangers is so great that in the many cases one metal ion can be separated from numerous metal ions. However we describe here in Tables I and I1 only a few of the possible separations for which experimental support has been obtained.

Table 1 1 Separations Practically Achieved on Stannic Phosphate Papers 1.

Solvent system n-Butanol-HC110% NHaCl (7:2 :1)

n-Butanol-HC1 (7:3)

n-Butanol-WC1 (8:2)

Separations achieved Time Au-3 (l,OO)-Pd+z (0.70-0.53)3-3.5 hr Pt+4 (0.16-0.00) ALI-~ . OO)-V5 (0.24) (1 3-3.5 hr Al+S (0,20-0,OO)-Zn+2 (0.90-0.70) 3-3.5 hr Pb+Z (0,27-0.00)-Zn+2 (0.90-0.70) 3-3.5 hr 3-3.5 hr CU+' (0,34)-Cd +Z (0.75) 3-3.5 hr Sb+8( 0 .90)-Fe+3 (0.35-0.22) As+3 (0.46-0.34) 3-3.5 hr cu+z (0.34) 3-3.5 hr Ag" (0.40-0.00) 3-3.5 hr Pb+' (0.40-0.00) 3-3.5 hr Snt2 (0.40-0.00) 3-3.5 hr Al+3(O107)-Be+2(0.38)-Fe+3(0.81) 3-3.5 hr Al+3(0,07)-C0"~(0,46)-Fe+3(0.84) 3-3.5 hr Tl+ (0.07)-Cu-2 ( 0 .48)-Hgf2 (0.78) 3-3.5 hr Pb"2(0.01)-Cu+2(0.48)-Hg+Z(0.78) hr 3-3.5 Ti+' (0,02)-UO~+~. 8 ( 4) 0 3-3,5 hr Fef3 (0.82) Ti-4 (O~O2)-Vr4 (0.49)-FeL3(0.83) 3-3.5 hr Ni+2(0.13)-C0+~(0.45)-Fe+~(O.83) hr 3-3.5 Mn-2 ( 0 .21)-CuL2 (0.49)3-3.5 hr Fei3 (0.84) N F 2 (O.12)-CuC2 (0.49)3-3.5 hr Fe+3 (0,90) Pb+' (O.O~)-CU+~ (0.49)3-3.5 hr Fef3 (0.90) PbC2 ( 0 .02)-Zr2 (0.77) 3-3.5 hr Thf4(0.01)-V+5 (0.43-0.17)' 3-3.5 hr M o + (0.58-SFblue) Vf6 (0.43~ 3-3.5 hr 0.17) Pt-4 ( 0 .15-o.o0)-~e+3(0.613.25 hr 0,30)-A~+~ (1.00) Mn+2(O.ll)-Zn+z (0.87)3.25 hr UO2+2 (0.46) T1+ ( 0 ,04)-Cufp ( 0 .40)-Hg+2 (0.90) 3.25 hr Mn+2 ( 0 .10)-Zn+Z(0.86) 3.25 hr Fe+S( 0 .62)-Al+3(0.05) 3.25 hr K+ ( 0 .02)-MoL6( 0 . 5 8 ) 3.25 hr U02+2 (0,37)-CS+ (0.00) 3.25 hr 3.25 hr U02+2( 0 .39)-CeA8(0.00) UOz+2 38)-Laf3 (0.01) (0. 3.25 hr UOz+' ( 0 .39)-Th+4 (0.01) 3.25 hr TiT4(O.OO)-Mo+e (0.56) 3.25 hr Wi6 (O,OO)-Mo+B (0.56) 3.25 hr 3.25 hr Pt+4 ( 0 .20-0.00)-Pd+2 (0.60)

Solvent system 0.1N "08 0.5NHN03 2ArHC1-2M H3P04 (1 :1) 1N HCl2M H3P04 (1 :1)

0.5NHC1

1N HC1-lM H3PO4 (1:l) 2N HCl-4N NaCl(1: 1) n-Butanol"03

( 8 :2)

0 .O5N NaCI0. 0 5 ~ HCI 7

Separations achieved K+ (0.02)-~e-3(0.72) Ga+3(0.92)-PbC2 (0.00) K' (0.46)-C~+ (0.16) K+ (0.58-O136)-Cs- (0,28-0.05) Sb+3(0,07)-Sb+' (0.36) Hgzf' (0,80)-Hg"' (0.00) Ag+ (O,OO)-Pt+' (0.80-0.58) Au-3 (0.51-0.31) K+ (0.70-0.50)-Cs" (0.28-0.10) Ag+ (0,00)-Cu+2 (0.55) TI+ ( 0 .O~)-ZII+~ (0.73) K+ (0.55-0.38)-Ti+4 (0.00) Pt+4(0.84)-UO~+~ (0.00) Pt+ (0,82)-C~+(0.39) Pt+4(0,82)-Ag+ (0.00) Ag+ ( 0 .OO)-CU+~ (0.40)HgAZ (0.85) Pt+?(0.81)-Fef3 (0.01) Sb+3(0.01)-Znf2 (0.50-0.27) Sb+3(O.Ol)-Cd+2 (0.60-0.25) K+ (0,70-0.45)-Cs+ (0.40-0.28) Hgf2 ( 0 .89)-Cr+3 (0,44) A d 3(0.54-0.30) Sb+5 (1.00) from Be+Z (0.00) B P 9 (0.26) Pd+2 (0.25) from Tef4(0.00) Fe+3(0.00) C U +(0.07) ~ Auf3 (0.97-0.78) Pt+4(0.93) from Ti-4 (0,OO)
W+6 (0.00) U02+2(0.00)

Time 3.25 hr 3.25 hr 20-25 min 20-25 rnin 25 rnin 25 rnin 30 min 30 rnin 30 rnin 30 mill 20 min 20 min 20 min 20 min 20 min 20 min 30-35 min 30-35 min 30-35 rnin 50 min for 15 cm 2.5 hr 5.5 hr for 15 cm for 15 cm for 15 cm for 15 cm 20-25 min 45-50 min for 15 cm

(1 :1)

1N HN03-2M (NH&HP04 (1 : 1)

As+3 (0.71-0.22) Ag+ (0.00) 45-50 rnin As+3 cO.71-0.22) from C U +(0.04) for 15 cm ~ Sn+2 (0.02) for 15 cm Sb'j (0.55) for 15 cm Cs+ (0,61),Rb+ (0,62),and K+ (0.65) 30-35 min from Ce+4(0,OO) 50 min Ti+?(0.00) 15 cm Zn+2(0,02) Cd+Z (0.01) Fe+3(0.00) Hg+2 and N P 2 (0.06) Sb+5(0.01)

1768

e

ANALYTICAL CHEMISTRY

Separations Practically Achieved on Stannic Phosphate and Stannic Tungstate Papers. Numerous important separations were found possible. However, a few were tried on stannic phosphate papers in order to find experimental support for the separations described in Table I. In this case only those separations were verified where the metal ions had RF value close to the ion separated. All the binary and ternary separations on stannic tungstate papers were practically achieved. The results are given in Tables I11 and IV. The method of preparation developed for these papers has the important advantage that the R p values are very reproducible without any problems whatsoever. Table V verifies this statement. In order to determine the charge on the ions separated, electrophoresis was performed in aqueous solvent systems used. The results are summarized in Table VI. The major separations on stannic phosphate paper were experimentally checked and it was found that A u + ~ sepis arated from a mixture of Ag+, Pb-2, C d P , Fe+3,C O - ~ , N F 2 , MgP2, Cat2, Sr+2,Ba+2,Be+2,Al+3, Zr+'. Mn+2,C r 3 , Th+4, U0zf2, and R u + ~ using n-Butanol-HC1-10 NH4C1 (7:2 :l). Platinum was also separated from the same mixture of cations in 25 minutes using 0.05N HC1-0.05N NaCl (1 :l). Sb+5,Hg+2, and K+, Rb+, Cs+, were also successfully separated from mixtures of more than 30 cations.
DISCUSSION

Table IV. Experimental Justification for Separations on Stannic Tungstate Papers Given in Table I1

Solvent system 4iVHCOOH 4N HCl(8 :2) 1N HCOO NH'

Separations achieved Ca+2 (0.80)-BaA2(0.41) in ratios varying from (10 :1) to (1 :10) Mg-2 (0.86)-Baf2 (0.12-0.00) in ratios varying from (1O:l) to (1 : 10). Mg+2 (O.83)-Sr2 (0 47)Ba+Z (0.18-0.00) Mg-2 (0.89)-Ba+2(0.20) W 2( 0 .65)-Ba+2(0.25)

Time
20 rnin

+

20 min
20 min
20 min 20 min

The results show that papers impregnated with stannic phosphate and stannic tungstate are exceedingly useful for important analytical separations. Thus gold can be separated from 36 metal ions in about 3.5 hours on stannic phosphate papers. Similarly Sb+3can be separated from 35 cations using the same solvent in the same period. The cations include Snf2, As+3, Fef3, Ag+, Pb+2, and C r 2 . These are most troublesome in the separation of Sb+3 and they are found to occur mostly in minerals and ores of antimony. Sb+j can be separated not only from Sb+3 but from 36 other metal ions in 5.5 hours. Similarly magnesium can be separated from 37 metal ions in 20 minutes on stannic tungstate papers. Molybdenum is also easily separated in the same time from 42 metal ions including Fef3, V+4$ Cr+3,Ti+4,N P 2 , and Mn+2 which interfere in the determination of molybdenum, Selenium separates from 33 metal ions including Te+', Pb+2, Hg+2,B P 3 , C P , Zn+*, Fe+3, As+3, Sb+3,T1- in which it is found as an impurity. As far as we are aware, separations of Mg+2,MoT6,and Se+4from numerous metal ions have not been reported in the literature up till now. The other separations ,in which one metal ion is separated from numerous metal ions are an improvement over the available paper chromatographic methods. Important binary and ternary separations have also been achieved with efficiency, ease, and compactness. Thus on stannic phosphate papers Fe-3, Al+3, and Be+* are separated in 3.5 hours. All the three spots are well defined and well separated. This is probably the best separation of Fe+3, A P 3 , Be+2yet reported. K+ and Cs+ can be separated in a number of solvents. The simplest separation needs half an hour and the developer used is 0.SN "Os. Selenium is easily separated from tellurium in 20 minutes on stannic tungstate papers while other available methods require more time to separate the two. Ag+-Pt+4-Au+3, Ag-C U - ~ - A U + have been separated in 2 hours giving compact ~, spots. The separation of all the platinum metals according

2N HCOOH 2-44 HCOO NH4 (2 :8 ) 0.5N HC1 K+ (0,81)-C~+ (0,52) ( Butanol 5 0 z Be+Z 0 .29)-AP3 (0,08) Be+2(0.29)-BaA2 (0.00) (v/V) "03 (7 :3) Butanol 50% UO2+2 (0.80-0, 53)-V+4 (0.27)Mo+' (0.10-0.00) ( V h ) "03 UOa+' (0,80-0.53)-V+4(0.27)(6:4) Ag+ (0,OO) Ag+ (O,OO)-Pb+' (0.24)UOa+' (0.80-0,53) Ag+ ( 0 .OO)-CU+' (O128)-Au-' (0.98) Ag+ ( 0 .OO)-Pt+4(0.61)-A~+~ (0.98) Dioxane 5 0 z Ag+ ( 0 .00)-Tlf (0.52)I d 3 (0.95-0.71) (v/v) "0s (1 :1) PtT4(0.96)-Pd+' (0.20-0.00) 0.1M (NH& V+' ( 0 .OO)-Mo+' (1 .OO-O. 8 8 ) COa Pt+4( 0 , 9 6 ) - R ~ +0~O O ) ( , Pt+4(0.96)-A~+~ (0.00) Mo-6 (1,OGO.88)-Cr+3 (0.00) Mo+6 (1 .00-0.88)-Ti-4 (0.00) 0.5N HC1 Hgz+' (O,OO)-Hg-': (0.90) saturated KC1 Ce+3(0,82)-Ce+ (0.06-0.00) solution (1 : 1) Pt+<( 0 .80)-Auf3 (0.55-0.36)-

+

+

20 min 2 hr

2 hr
2 hr

+

2 hr
2 hr
2 hr 2 hr 2 hr

+

20 min 20 min 20 rnin 20 rnin

+

20 min 20 min 20 min 20 min 20 min
20 min 20 min 20 min 20 min 20 min

1r+4

(0.00)

0,liMAmmonium tartrate in 4M ",OH 0.5iM CH,COONa

Ce+' (0.06-0. OO)-Yf3 (0.82) Ce+?(0,06-0. OO)-La+3(0.86) Ce+4(0.06-0. 00)-Nbf6 (0.88) Pt+4( 0 ,93)-W4 (0.00) Be+a (0.70-0.47)-Fe'3 (0.12-0.00) SeT4 (0.86)-Tet4 (0.07-0.00) Mo+' ( 0 , 9 1 ) - A ~ (0.08-0.00) +~

20 min 20 min 20 min

Table V.

Reproducibility of RF Values on Stannic Phosphate Papers

Metal ion

Solvent system

1st

Rr Value 2nd

3rd

Pd+2 n-Butanol HN03-Hz0 (8:l:l) Hg+2 2iV HCl-4M NaCl (1:l) Au+3 Butanol-HCl-10% NHaCl(7 :2 :1) Pt+4 Butanol-HCl-10% NHrCl (7 12: 1)
K+ 0.5N
"03

+

0.42-0.20 0.36-0.18 0.36-0.20 0.984.79 0.97-0.83 0.96-0.80 0.99 0.98 1.00
0.20-0.00

0.15-0.00 0.16-0.00

Sn+2 0,05iVNaCl 0.05N HC1 (1 :1)

+

0.56-0.36 0.56-0.36 0.56-0.36 0.05-0.00 0.05-0.00 0.04-0.00

VOL. 39, NO. 14, DECEMBER 1967

0

1769

Table VI. Electrophoretic Determination of Charge on Different Ions in Some Aqueous Solvent Systems Cations Solvent Positively Negatively Unsystem charged charged charged 0.5N HCl K+, TP4,UOzt2, Ptf4,Hg+z ... CuL2, Fe+3 2N HC1-4M Fe+3, Ni+2, Kf, Cua2,Cd+2, As+a, . .. NaCl(1: 1) Cs+ HgCz 0.05N HC1Ptf4 As+3,Cuf2 ... Q.05NNaCl 1N FINO3Fef3, KT, Cs+, 2M Rb+, Cdf2 ("&So4 Q.5N"0s K", CSf 2N HC1-2M Sb+' HsP0.j (1 :1) 1N HCl-2M K+, Cs+, CU*~, HaPo* (1 :1) Zn+2, Pt+4 1M Ba+2,K+, Rb+, HCOONH4 Cs+, Zrf4 1M (NH4)2C0s Pd+2,Ti+4 0.1MAmmo- K+ nium tartrate in 4M NHiOH 0.51v ... CH3COONa 0 . 1M HN03 Fefa 0.5N HC1 Ce-4 saturated solution oi KCl(1:l) 4N HCOOH4h7HC1 f 8 :2)
(1:l)

N P , C d 2 ,Cuf2, Ptf4 Hg+z Ptf4,T1+, A d 3
I . .

...

...
Sb+S

...

...
Cr+3,A U + ~ , Ru-~ AU+~

Pt+4, Mo+e Se+4, Mof6, V+4

Pt-4,

uo2+2

Te+

-+

Pt+4 ... Hg+2,Pt+l, Au+3, Ir+4,M O + ~ Pd+2,Nbf6 Cafz

...

to Burstall (20) takes 20 hours. However, we have developed binary and ternary separations of platinum metals which need only 20 minutes for completion. Potassium, Rb-, Cs+, and Cd+2show a linear increase with an increase in the concentration of HC1 when chromatographed on stannic phosphate papers. Pt+4, Al+3, and Bef2 do not show a change in RF values with increase in HC1 concentration. This is because as the HC1 concentration increases, water is replaced from the hydrated alkali metal ions. In the case of Cd+2,the explanation is more probably to be found in the complex formation. T o study whether the cations which remain at the point of application on stanic phosphate papers do so as a result of precipitation or owing to the formation of positively charged species, paper chromatography of all these ions was performed on plain paper. In 0.5N HNOa B P a , Sb-3, Th+4, UOZ+*, Te+4, all had RF values from 0.80 to 0.88. This therefore

shows that all these ions form positively charged species in 0.5N "03 and are therefore retained at the point of application when chromatographed on stannic phosphate papers. Fe+3, Zr+4,and TP4, however, tail owing to the formation of many ionic species. In 2N HC1-4M N a C l ( 1 : l ) Ce+3,Th-', Sb+3, Ti+4,all had RR values from 0.86 to 0.92 and therefore form cationic species; only Zr+4 tails. In 0.1M H N 0 3 Pb+Z,TI+, Fe+3, UOZ+~, P 3 , Te+4, Ga+3, Ce+3, Y + 3 ,and La+3 all had A Rr values from 0.80 to 0.90 when chromatographed on untreated papers; only Bif3, Sb+3, and Ti+4 tailed from the point of application to an R p value from 0.90 to 0.94 on untreated papers, while Ag+, Sb+3, Zr+4 tailed. In 0.05N NaCl-O.05N HCl (1:l) Pb+2, C O + ~ Mn+2, ZnA2, Ce+3, , U02.+2, Ga+3,Nif2, Cdf2, C U + ~ , T1+ had R pvalues from and 0.80 to 0.90, showing thereby that they form cationic species. In 1 N HC1-2M H3PO4(1:1) Ag+, Tl+, and Th-4 all tailed showing a lack of equilibrium in the system. Hg,+2 stayed at the point of application as a result of precipitation. In 1N HC1-1M H3P04 (3:7) Ag+, Ce+3, and Th+' stayed at the point of application as a result of precipitation. In 1 N HN03-2iM(NH4)z H P 0 4 (1:l) Pb+2, Y+3, Cef3, La+3, Th+4,i Y 4 , Ag-l-, Hgzi O, all had zero RF values on untreated papers showing thereby the formation of insoluble (1 :1) Ag' phosphates of these ions. In 2N HC1-2M and Hg+2stayed at the point of application, since both of them form insoluble chlorides. Sb73 and Th+4had R, values close to 0.82 since Sb+3 and ThC4phosphates are soluble in HCI forming positively charged species. The mechanism of the separations on stannic tungstate papers was also studied. Thus Chromatography was performed on plain Whatman No. 1 papers for those cations which had zero RF values on stannic tungstate papers. It appears that the following cations had zero RF values owing to precipitation in the solvent systems mentioned against them : Fe+"lM HCOONH4; Ag+ and H g ~ + ~ - 0 . 5HC1; FeT3, N Ti+4, In+3, R u + ~Fe+2,and Pb+2-0.1M (NH&C03; Hgz+z, 0.1M "03 The charges on the cations were determined by electrophoresis and it was found that those cations which have positive charge in the solvent system either remain at the starting point or move to a very little distance while those having negative charge move to greater distances from the starting point. Magnesium, however, showed an exceptional behavior in 1N HCOONH4 and 0.1N H N 0 3 on stannic tungstate papers, which needs further study before definite explanation can be given. ACKNOWLEDGMENT The authors are grateful to A.R. Kidwai, Head of the Department of Chemistry, for research facilities and encouragement. RECEIVED review October 6, 1966. Resubmitted May 30, for 1967. Accepted August 14,1967.

(20) F. H. Burstall, G. R. Davies, R. P. Linstead, and R. A. Wells, J . Chem. Sac., 1950,516.

1770

a

ANALYTICAL CHEMISTRY


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