ANALYTICAL CHEMISTRY
64 (11) (12) (13) (14) (15) (16)
Garwin, L., and Hixon, A. N., I n d . Eng. Chem., 41, 2298 (1949). Golumbic, C., J . Am. Chem. Soc., 71, 2627 (1949). Golumbic, C., Orchin, M.. and Weller, S., Ibid., 71, 2624 (1949). Gorley, J. T., U.S. Patent 2,457,887 (1949). Guinot, H. M., and Chassaing, P., Ibid., 2,437,519 (1948). Hogeboom, G. H., and Barry, G. T., J . Bid. Chem., 176, 935
(1948). (17) Hsiao, S. C., Science, 107, 24 (1948). (18) Huffman, E. H., and Beaufait, L. J.. .J. A m . C’hem. Soc., 71, 3179 (1949). (19) Kolb, J. J., Science, 109, 378 (1949). (20) Kuznetsov, V. I., J . Gen. Chem., (C7.S.S.R.),17, 175 (1947). (21) Lash, J. J . , Am. J . Clin. Pathology, 18, 584 (1948). (22) Livermore, A. H . , and du T’igneaud, Y.,,J. Biol. Chem., 180, 365 (1949). (23) McBryde, W.A. E., and Yoe, J. H., A s i i . . (’HEY., 20, 1094 (1948). (24) Micaelli, O., and Desnuelle, P., Bull. meus. ITERG, 1948, No. 7 , 31-3. (25) Nolan, L. S . , ANAL.CHEY.,21, 1116 (1949). (26) Norstrom, 9., and S i l l h , L. G., Snensk. Kern. Tid., 60, 227 (1948). (27) O’Keeffe, 9. E., Dolliver, M.A., and Stiller, E:. T . , J . Am. Chem. Soc., 71, 2452 (1949). (28) O’Keeffe, -4.E., Russo-Alesi, F. M., Dollirer, M.A . , and Stiller, E. T., I b i d . , 71, 1517 (1949). 129) Peck, R. L., Hoffhine. C. E., Jr.. Gale, P.. and Folkers. K., Ibid.. p . 2590.
(30, Plattner. A . Heilbronner. E.. and Weber. S.. H e h . Chim. d c t u . 32,574 (1949). 131) Plaut. G. W. E., and Mr Coinlack, R. B.. J . .Im. Chem. Soc., 71, 2264 (1949). (32) Raymond, S., ANAL.CHEY.,21, 1292 (1949). (33) Rothschild, B. F., Templeton, C. C., and Hall, 9.I . , J . /’h,ys. and Colloid. Chem.. 52, 1006 (1948). (34) Scholfield, C . K., Dutton, H. J., Tanner, F. W.,J r . , and (‘owati, J. C . , J. Am. Oil Chemists’ Soc., 25, 365 (1948). (35) Smith, E. L., and Page, 6.E.. 6.Soc. Chem. Ind. ( L o n d o n ) ,67, 4h (1948). (36) Stein, W. H., and Moore. S..J . Bid. Chem., 176, 337 (19481. (37) Stern, H., and Kirk, P. L., Ibid., 177, 43 (1949). (38) Swart, E. A., J . Am. f‘hrm. Soc., 71, 2942 (1949). (39) Titus, E., and Fried, J.. .I. B i d . Chem., 174, 57 (1948). (40) Tsai, K. R., and Fu. Y . , As.LI,. CHEM., 21, 818 (1949). (41) Vanossi, R., Annlrs. sor. c i e n t . Argrnfinn, Seccidn Santu F e , 145, 207 (1948). (42) Warf, J. C., J . Am. (‘hem. S o c . , 71, 3157 (1949). (43) Weizmann, Ch., Bergmatin, E., Chandley, E. F., Steitier, €1.. Sulzbacher, M., arid Zirnkin. E., J. Snc. Chem. I d . (London), 67,203 (1948). (44) Wells, J. E., and Hunter, D. P., AnaZUst, 73, 671 (1948). (45) Woolley, D. IT., J . B i d . Chem., 179. ,593 (1949).
RECEIVEDNovember 23,
1H49
ION EXCHANGE ROBERT KUNIK Resinous
I
I’rodiicta Diitsion,
Rohm & Haas Company, Philadelphia, Pa.
p\’ LAST year’s review ( 1 4 ) of the application of ion exchange
techniques t o analytical chemistry, the basic principles of ion cxchange and the general nature of ion exchange materials were reviewed, in addition to the analytical applications. During the past year, considerable progress has been made in the use of ion exchange as a n analytical technique. I n particular, ion exchange materials have provcd themselves t o be useful both in chromatography and in conventional analytical methods. I n the latter case, the removal of interfering elements has been simplified in sclveral conventional analytical procedures. LITERATURE REVIEWS
In a chapter of a recent book on ion exchange, Rienian (18) has reviewed and classified the analytical applications of ion exchange. I t s use in the laboratory, in particular, the chromatographic te*chniques, has been reviewed by Tompkins (27, 28). The usefulness of ion exchange in rare earth and radioisotope chemistry has been discussed critically by Cohri, Parker, and Tompkins (6) and Steacie and Cambron (23).
ions was accomplished on the sanie resin, utilizing identical chromatographic techniques. The separation of the ribosr nucleosides, purine, and pyriinidiiw fragments of yeast nucleic acid has been accomplished in a most spectacular manner by Cohn ( 3 , 6 )using both anion and cation cxchange resins. Utilizing a sulfonic arid cation exchanger, Cohii found i t possible t o separate completely the purine and pyriniidine bases, uracil, cytosine, guanine, and adenine. I n order t o separate the nonionized bases, t,hymine and uracil, as well as the other bases, Cohn employed a strong base anion exchanger as the adsorbent. The separation of the nionoribosenucleic acids (uridylic, guanylic, cytidylic, and adenylic acids) has been accomplished by Cohn on a sulfonic acid exchanger. Bzcause the acids exhibit but slight basicity, their elution from the column was effected with a weak acid. The method perfected by Cohn ( 4 ) is suitable for most laboratories, as the chromatographic development can be readily followed and traced by means of spectrophotometric ahsorption techniques in the ultraviolet (260 to 265 mp) region. Refinements in the ion exchange separation of amino acids have been made by Rauen and Felix (21) and by Partridge (bo), the lattcr utilizing the Tiselius displacemcAnt techniqur.
IOh E X C H 4 h G E CHROM4TOGRAPHY
The separation of closely related ionic species by chromatographic techniques utilizing a n ion exchange resin adsorbent has been applied successfully t o several interesting inorganic and organic mixtures. Utilizing radioactive tracers, Tompkins (16)has shown t h a t radium and barium can be fractionated in a manner similar t o the rare earth separations. The citrate complexing technique has been used t o develop into bands the constituents previously adsorbed on a sulfonic acid cation exchanger. Similarly, Street and Seaborg (24) have separated the closely related ionic pair, hafnium-zirconium. Kraus and Moore (12, 13) have employed a most interesting technique for the separation of the pairs, zirconium-hafnium and columbium-tantalum, utilizing anionic complexes of these ions. Oxalate and fluoride complexes of zirconium and hafnium were chromatographically separated on a n anion exchanger of the strong base type. The complete separation of columbium and tantalum a s the CbF,-- and TaF;,--
REMOVAL OF INTERFERING ELEMEETS
Of considerable interest has been the utilization of ion escliange methods for removing intprfering constituents. In many convcntional methods of analvsis, anions interfere in the analysrs of several cations. Inasmuch as oppositely charged ions can be separated by means of ion exchange, these interfering ions can be removed readily. Sodium cannot be determined a s either the zinc or magnesiuni uranyl acetate in the presence of phosphates, molybdates, and ot,her anions that are capable of forming irisoluble precipitates with the uranyl acetate reagent. Klement and Dmytruk (11)recommend the removal of phosphates by means ot a n anion exchange resin prior t o the precipitation of the sodium. Linqvist (16) suggests the adsorption of sodium on a cation t:xchanger in order to separate the interfering elements. FIowrwr. this latter method requires the additional acid elution str,p prior to thc sodium precipita,tion.
65
V O L U M E 2 2 , N O . 1, J A N U A R Y 1 9 5 0 The interference of copper, iron, and other cations in the iodometric determination of arsenic has been eliminated by the utilization of a sulfonic acid exchanger in a procedure devised by Odencrantz and Rieman (19). T h r proredure involves the solution of the sample, oxidation t’othe quinqurvalent state, evaporation, re-solution, and passage through the cation exchanger in the hydrogen form. The arsenic is then determined iodometrically, using st,andard thiosulfat,c for the titrat,ion of the liberated iodine. This met,hod eliminates the distillation step recommended by the Association of Official hgricultural (‘hemists. This procedure is analogous to that developed by Helrich and Rirman (8) for t,he det.c)rmination of phosphorus pentoside in apatite. I n the determination of copper, iron, aluminum, calcium, arid magnesium, polybasic carboxylic acids such as oxalic and tartaric acids interfere because of their complexing and sequestering activity. Their removal usually requires a lmgthy oxidation with nitric w i d or aqua regia. In order to simplify the removal of thcse intcbrfering anions, Iclement and Dmptruk (10) have suggested thr. use' of an anion exchanger in t’he rhloridr form. Sulfate trace impurities prescxnt in gelatin used in thcs nrphelometric analysis of sulfates have been removed by Honda (9) with the aid of an anion cwhange resin. I t is probable that the gelatin, starch, and gun1 arabic used in many other trace analyses can be similarly purified b y ion exchange. I n order to eliminate the interference of calcium and iron rapidly in the colorimetric analysis of silica traces, Lagerstrom, Samuelson, and 8nholandw (15 ) rmployed a sulfonic acid exchanger in the hydrogrri form.
cerous ion and the cation exvharigt. resin in the presencta of tht. foregoing anions. ELECTROR EXCHANGE RESINS
Although no analytical methods have made use of the “elertron exchange” resins of Cassidy ( 2 ) , the successful synthesis of polyvinylhvdroquinone by Cassidy and his students (29) may lead t o a new analytical tool similar to the Jones zinc reductor or the silver modification of this reductor. Cassidv and his students have found resins of this type to form a reversihk oxidation-reduction system for the ceric-cerous and bromine-bromide equilibria. Although far from being perfected, these resins map bc of considrrable analytical significance in the future. LITERATURE CITED
Blumer, &I.,Ezperientia, IV, 351 (1948). Cassidy, H. G., J . A m . C‘hem. Soc., 71,402 (1949). Cohn, W. E., Ibid., p. 2275. Cohn, W ,E., personal communication. Cohn, W.E., Science, 109, 377 (1948). (6) Cohn, W. E., Parker, G . W., and Tonipkins, E. l < . ,.VuclroLcs. 3, No. 5 , 22 (1948). (7) Connick, R. E., and Mayer, Y. W., Abstracts, 116th hleeting AMER.CHEM.Soc., Atlantic (‘itg, p. 18P, 1949. (8) Helrich, K., and Rierilan, R.. 1x11.Ewn. CHEM.,.ix\t.. t.:~)., 19,
[l) (2) (3) (4) (5)
651 (1947). (9) (10) (11) (12)
Honda, >I., J . Chidm. .5’oc. J a p u n , 70, 52 (1949). Klement. R., and Dmytruk, R., Z . anal. Chem., 128, 106 (lY48). Ibid., p. 109. Kraus, K . A , arid Moore. 0. E.. .T. A m . f‘hpm. Sm-,,71, 1283 (1949).
DETERMINATIOh OF CO\CENTRATIOh
(13) Ibid., in press.
The drtermination of total electrolytr concentrations by ion excahange has become of considerable interest. Because it is possible to convert a neutral solution of an elec+rolyte complrtely into the free acid on passage through a rolumri of a sulfonic acid exchangu in the hvdrogen form, severnl investigators have studied this method for various c,lectrolyte mixtures. Blumer (1) has eniployed this method for ascertaining the total concentrationof natural tvater supplies and Tolliday, Thompson, and Forman ( 2 5 ) h a w adaptcd this proccdure to chroinr tan liquors. I)ETER\IIYATIOY OF EQUILIBRIUM COYSTANTS A-1) ACTIVITY COEFFICIEYTS
(‘ontinuing the work of Vanselow (30) and Schubert (22)on thr. u5e of ion exchange in equilibrium constant and activity coefficient measurements, ?*layer and Schm-artz (17) and Connick and Mayer ( 7 ) have determined the relative activity coefficients of (’eroussalts and the association betiwen cerous ions and the perchlorate, nitrate, sulfate, iodide, bromide, fluoride, sulfite, pho+ phatc, and pyrophosphate anions. The technique involves thcx rncrtwremrnt of thc comparative ion vxcahnngr equilibrium of the
(14) Kunin, R., . ~ K A L . CHI-M.,21, 87 (l94Y). (15) Lagerstrom, O., Samuelson. O., and Srholauder. X.. Swrish I’ny perstidn., 108, 439 (1948). (16) Linqvist, I., Acta Chrm. Srand., 2, 38 (1948). (17) Mayer, S. W., and Schwartz. S. D., Abstratts, 116th Meeting AM. CHEJI.Soc., p. lYP, 1949. (18) Nachod, F., “Inn Exrhange,” Sew Tork, Academic: Preas. 1949. (19) Odencrantz, J. T., and Rieman, W., Abstracts, 116th Meeting h f . C H E Y . S O C . , p. 15B, 1949. (20) Partridge, S.M.,Ch~mistrgKS Industry, 1949, No. 1, 12. (21) Kauen, H. >I., and Felix, K., 2. physiol. Chem., 283, 139 (1’448). f.22) Schubert, J., J . Phys. Colloid Chem., 52, 340 (1948). (23) Steacie, E. W. R., and Calnbron, .1., Research, 2, 225 (1949). 124) Street, I
