104
ANALYTICAL CHEMISTRY
(63) Mader, Charles, and Mader, George, Jr., ANAL.CHEM.,25, 1423 (1953). (64) hlason, A. C. F., Ibid., 25, 533 (1953). (65) Metcalfe, T. B., “Study of Flooding in Packed Columns,” Ph. D. thesis, Georgia Institute of Technology, 1951. (66) Michell, D., J . Appl. Chem. (London),1, Suppl. 1, S8-9 (1951). (67) Miller, G. H., J. Chem. Educ., 29, 73-4 (1952). (68) Murch, D. P., Chem. Eng. News, 30, 520 (1952). (69) Murray, K. E., and Schoenfeld, R., J . Am. Oil Chemists’ Soc., 28, 461-6 (1951). (70) Natural Gasoline Association of ilmerica, Chem. Eng. News, 30, 432 (1952). (71) Ibid.,p. 2093. (72) Natural Gasoline Association of America, Tulsa, Okla., “Liquefied Petroleum Gas Specifications and Test hlethods,” 1951. (73) Newton, W. M.,Mason, J. W., Metcalfe, T . B., and Summers, C. O., Petroleum Refiner, 31, N o . 10, 141-3 (1952). (74) Orrick, N. C., and Gibson, J. D., ANAL.CHEM.,23, 1100-3 (1953). (75) Pantages, Peter, and Feldman, Julian, I d . Eng. Chem., 44, 2783 (1952): (76) Perry, E. S., L . 8. Patent 2,678,086 (Dec. 11, 1951). (77) Peters, &I. S., “Vacuum Distillation.” Ph.D. thesis, Pennsylvania State University, 1951. (78) Peters, M. S., and Cannon, hl. R., Ind. Eng. Chem., 44, 1452-9 (1952). (79) Pigford, R . L., Tepe, J. B., and Garrahan, C. J., Ibid., 43,2592602 (1951). (80) Piros, J. J., and Glover, J. A , U. S . Patent 2,573,807 (Nov. 6, 1951). (81) Ibid., 2,608,528 (-4ug. 26, 1952). (82) Podbielniak, mi. J., Deyle, C. hZ., Marco, Carl, and Turkal, Peter, “Recent Improvements in Mechanized Low-Temperature Analytical Distillation Apparatus,” Divisions of Petroleum Chemistry and Analytical Chemistry, Symposium on Automatic Analytical Methods in the Petroleum Industry, 124th Meeting, AM. CHEM.SOC., Chicago, Ill., September 1953. (83) Pohl, Herbert, Erdol u. Kohle, 5, 291-4 (1952). (84) Pratt, H . R. C., Trans. Inst. Chein. Engrs. (London),29, 195210, discussion, 210-14 (1951). (85) Preston, S. T., Jr., Petroleum Refiner, 32, KO.4, 142-4 (1953). (86) Ibid., Yo. 8, pp. 109-14. (87) Putt, J. W., Smith. J. O., Jr., and AIcLean, J. O., U.S. Patent 2,622,062 (Dee. 16, 1952). (88) Radin, E.S., Ax.4~.CHEM.,24, 1686-7 (1952). (89) Renshaw, il., Chemistry & Industry, 1953, 294-5. (90) Rollet, A. P., Bull. soc. chim. France, 1952, 539-44. (91) Romanet. Ren6, Compt. rend., 235, 1390-2 (1952). (92)’ Rose. Arthur, h i . 4 1 , . CHEM.,24,60-4 (1952); 23, 38-41 (1951); 22, 59-61 (1950); 21, 81-4 (1949). (93) Rose, Arthur, Johnson, R. C., and Williams, T. J., Cheni. Eng. Progr., 48, 549-56 (1952). I
(94) Rose, Arthur, and Rose, E. G., “Distillation Literature Index and Abstracts, 194652,” State College, Pa., Applied Science Laboratories, 1953. (95) Rose, Arthur, Williams, T . J., and Kahn, H. A., Ind. Eng. Chem., 43, 2608-11 (1951). (96) Santos, M. S., Ion, 13, 11-13, 21 (1953). (97) Schram, Eric, and Bigwood. E. J., Ax.4~.CHEY., 25, 1424 (1953). (98) Schultze, G. R., and Stage, H., Dcchenm Monograph, 14, S o . 143/56, 17-40 (1950). (99) Schwartz, C. E., “Flow Distribution in Packed Columns,” Ph.D. thesis, Purdue L-niversity, 1951. (100) Sherwin, C. W., Rea. Sci. Instr.. 22, 339-41 (1951). (101) Shire, W. A., C. S.Patent 2,575,193 (Nov. 13, 1951). (102) Shorland, F. B., J. Appl. Chein., 2, 438-40 (1952). (103) Silverstein, R. M., and Englert. R. D., Chemist Amlust, 41. 15-17 (1952). (104) Simpson, D. A., and Sutherland, 31. D., ANAL. CHEM.,23, 13456 (1951). (105) Sims, R. P. A., “hlicromolecular Still,” Chemical Institute of Canada, Montreal, June 1952. (106) Smith, T. R., U. S. Patent 2,575,688 (Nov. 20, 1951). (107) Stage, H., Fette u. Seijen, 53, 677-82 (1951). (108) Ibid., 55, 217-24 (1953). (109) Steward, K., Gas World, 137, 794-5 (1953). (110) Stokes, C. S.,and Hanptschein, Murray, ANAL.CHEM.,24, 1526 (1952). (111) Sugimura, G. H., and Reynolds, T. W., “Evaluation of Packed Distillation Columnsat Atmospheric and Reduced Pressures,” Section 14, Physical and Inorganic Chemistry, XIIth Internatienal Congress of Pure and Applied Chemistry, S e w York, 1951. (112) Swarr, J. N., Trans. Am. Soc. Mech. E’ngrs., 74,891-903 (1952). (113) Teller, 9. J., “The Rosette, A New Packing for Diffusional Operations Based on High Interstitial Holdup,” Am. Inst. Chem. Engrs. Meeting, San Francisco, Calif., September 1953. (114) Varner, J. E., and Bulen. IV. .i., J. Chem. Educ., 29, 625-6 (1952). (115) Weingartshofer-Olmos, A . . and Giguere, P. A., Chem. Eug. News. 30. 3041 (1952). (116) Wilcox,’.4. ’C., Cdulter; K. E., and Lloyd, L. E., Petroleum Refiner, 31, KO.2, 134-6 (1952). (117) Williamson, G. J., Trans. I&. Chem. Engrs. (London), 29, 215-24, discussion, 224-5 (1951). (118) Wingo, W. J., and Browning. Iben, ANAL.Cmnr., 25, 1 4 2 6 7 (1953). (119) Wolff, C. J. de, Pharm. W e e l h l n d , 86, 273-5, 335 (1951). (120) Zahn, R. K., Chem.-Ing.-Tech.. 24, 620 (1952). (121) Zuiderweg, F. J., Chem. Eng. Sci. (London), 1, S o . 1, 8-17 (1951). (122) Ibid., NO.4, 164-74 (1952). (123) Ibid., pp. 174-93. (124) Zuiderweg, F. J., Chem.-Ing.-Tech., 25, 297-308 (1953). (125) Zuiderweg, F. J., Ingenieur, 64, CH 6 3 4 (1952).
Ion Exchange ROBERT KUNiN and FRANCIS X. MCGARVEY Rohm
A
& Haas Co., Philadelphia, Pa.
SURVEY of the literature on ion exchange during the past two years has shown a continued interest in the use of ion
exchange techniques in many analytical chemical problems. An indication of the role of ion exchange in analytical chemistry is evident upon examination of a recent text written b y Samuelson (bS7), entitled “Ion Exchange in Analytical Chemistry.” This outstanding contribution reviews the theory and practice of ion exchange in its application t o analytical chemistry and to many other allied fields. It is of particular interest in t h a t Samuelson suggests procedures t h a t have been investigated sufficiently so t h a t they may be placed on a routine basis, thereby enabling the control analyst t o conduct analyses with ion exchange with b u t a minor amount of exploratory research. Although the interest in the use of ion exchange in analytical chemistry is rapidly increasing, t h e actual number of quantitative methods that are of general use are few. T o date, the chief
analytical uses for this technique appear t o be divided among separations in biochemical analysis; separations of metallic complexes from one another and from materials not capable of forming complexes; roncentration of dilute solutions; and t h e determination of total ionic concentration in various solutions, natural water supplies in particular. I n addition, several difficulties encountered with this technique have hindered the universal acceptance of ion exchange in analytical chemistry. Some of these difficulties are t h e impurities encountered in “run-of-the-mill” commercial resins; variations in results with various samples of the same commercial grade of ion exchange reqin; and unfamiliarity with the general principles of ion exchange. However, regardless of these difficulties, i t has been generally accepted b y those experienced with the technique t h a t a considerable number of useful analytical procedures employing ion
V O L U M E 2 6 , NO. 1, J A N U A R Y 1954 exchange can be developed if use is made of the available theory relating such functions as distribution coefficients, exchange capacity, ion valence, and pH. REVIEWS
I n addition to Samuelson’s major contribution ( W 7 ) , several escellent reviews have appeared which encompass the properties, applications, and theories of ion exchange. Recent studies in England have been summarized by Kressman (166), Duncan (81).and Pepper (219). Osborn (612) has compiled a11 excellent bibliography on the use of exchangers in analytical chemistry. Special reviews on ion exchange in drug, fine chemical, and pharmacy applications have been prepared b y Lesser ( 17 8 ) and Bucki ( 4 8 ) . T h e Manchester Section of the Society of Chemical Industry (6W),Kings College (63), and the Gordon Research Conference held conferences which reviewed recent developments in this country aiid abroad. Boyd (35), Bauman et al. (16). Kunin (171), and Cassidy (-56)have written extensive reviews covering ion exchange theory and application. Tiselius (2781, Rasinslii ( 1 6 ) , Tonipkitis (279 1, and Samuelson (239) have summarized xork in Europe. THEORY
The development of the t,heory of ion exchange went through a pcriod of consolidation in the past t\To years. Emphasis has been placed on the development of thermodynamic relationships in a form similar to those derived for soluble electrolytes. T h e role played by the polymer structure on ion exchange equilibria aiid physical properties of the system has been investigated l)y several workers. Glueckauf (100) and Duncan (82) have extended the recently ticvelopetl theory of Gregor employing the concept that exchangers are similar to homogeneous solutions of similar concentration. Boyd and Soldano ( 3 6 ) have measured and calculated the osmotic free energies of exchange systems. Davies (76) has developed a theory relating the adsorption and snelling properties of weak base-type anion exchangers. Bonrier et al. (10, 81-33) have determined equilibrium constants for several monovalent cation exchange systems using the Gibbs-Duhem relationship. Betts ( 2 2 ) developed a relationship for the exchange of ions in solutions of mixed electrolytes. The equilibrium for the exchange of organic bases n i t h a carboxylic exchanger has been studied by Saunders (245). Pepper (217-219), Hale ( I l l ) , and Kuhn (170) have reported on the influence of polymer structure on ion esrhange reactions. T h e selective behavior of the carboxylic acid gmup of ion exchange resins has been discussed b y Deuel ( 7 7 ) . Bregman et al. (37, 6 4 ) have reported on the properties of pliosphonous and phosphonic acidtype cation exchange resins. The preparation of exchangers which show selective affinity for specific cations has been described b y Klyachko (161). Vicnkery (289)has t,he correlated ion exchange elution data with st:rhility of rare earth complexes. Partridge (214 ) has employed ion exchmge resins as molecular sieves and has developed a concept of this phenomenon. Mysels (206)has made an attempt to explain certain p H changes occurring in colloid systems by means of ion exchange equilibria. Honda (IRS), Kagawa (145), and Knkihann ( 147) have determined equilibrium constants for several exrhangc. systems. The theory of column performance has been developed by Vermeulen (286, $87) for aqueous and nonaqueous system,.. Cherkin (6.5) calculated and studied a gradient elution procedure which reduces the tailing effects in chromatographic columns. Wheaton and Rauman (698) reported on the application of ion exclusion techniques for the separation of non- or weakly ionized substances from strong electrolytes. NEW ION EXCHANGE MATERIALS AND METHODS
105 polymers capable of undergoing oxidation and reduction reactions have been prepared and studied by Cassidy (66,67,85). Gregor et al. (106) reported on the properties of exchangers containing chelate groups. Ion exchange materials based on cottons were prepared by Guthrie (109). Phosphonic acid groups were introduced into a polymer by Daul and Reid ( 7 3 ) . D’Alelio ( 7 1 , 7 2 ) produced cation exchange resins from the sulfonation of styrene-aryl acetylene copolymers. Bodamer (28-30) described the preparation of permselective films of cation and anion exchange resins b y impregnation of finely divided ion exchange particles into a polymeric matrix. Bodamer ( 5 0 ) also produced carboxylic cation exchanger from “popcorn” polymers of acrylic acid and polyolefinic materials. Bauman ( 1 7 ) synthesized quaternary-type anion exchangers from tertiary amines. Gapon (86) and IIarconi (191)developed modified methods for the determination of total capacity of cation exchangers. Sasaki (244) employed a conductometric titration procedure to determine the capacity of cation exchangers. Minami (196)used elcctrometric methods to evaluate the effluent composit,ion of cation exchangers used to separate hydrogen, rubidium, and cesium. Leick (176) studied several hydrogen-cycle ion exchange systems. Roberts 1227) developed an ion exchange demonstrat,ion experiment for physical chemical laboratory. Calmon (61, 62) made use of the volunie changes observed in low cross-linked cation exchangers as a measure of ionic strength and valence of ions in solution. Grunbaum (108) developed a capillary huret for reagent generation which employs ion exchange resins. Honda ( 1 2 6 ) used a highfrequency oscillator t,o locate c.hromatographic bands within the ion exchange column. ISORGANIC SEPARATIONS
Ion exchange resins have been employed for ninny ne\? iriorganica separations. Routine use of ion exchange resins has been reported by Spedding et al. (61, 269) and Tevebaugh (274) for rare earth separations. -4 contiuuous and automatic method was reported by Luigi (188) for the same purpose. Various improvements in these procedures were reported by Trombe and Loriers (280, 281). T’ickery (288) compared the efficiency of various eluting solutions for ion exchange chromatography. -4 procedure for the separation of titanium, zirconium, and thorium was developed by Brown and Rieman (40, 41 ). Radhakrishna (222, 223) separated thorium from the rare earths. The separation of basic aluminum ions has been reported by Honda (124) while Kakihana ( 1 4 6 ) has developed a procedure for the separation of beryllium from aluminum. Lister (182)studied the solution chemistry of zirconium by means of ion exchange. Freund ( 9 0 ) used ion exchanger resins tmoseparate zirconium from aluminum. Kraus ( 1 6 4 ) used an anion exchange resin to separate ferric sulfate complexes from aluminum sulfate. Pure protoactinium isotopes were prepared by Barendregt (14). Blasius (25) studied the borotungstate complexes using strong base anion exchange resins. The separation of molybdates of several heavy metals has been examined by Klement (160). Fisher and Meloche (88)have separated rhenium from molybdenum on strong base exchangers. T h e elution of niobium was studied by Huffman and Iddings (133). A process for the recovery of gold from cyanide leach solutions has been reported by several British workers (49). Leden (174) proved the presence of anionic complexes in cadmium and copper solutions. Isomeric complexes of cobalt were separated b y King and Walters (157). West (296) fractionated cobalt complexes. Salmon and Tietye (256) have studied the separation of tetraand pentavalent vanadium ions in phosphoric acid solutions. Hering (117) has separated quantitatively traces of lithium from calcium. Ryabchikov and Bukhitiarov (235) used ion exchange chromatography to separate copper and iron. Iron complexes were invest’ieated b v Whitaker (299). Fronaeus ( 9 1 ) measured the equilibrium between nickel and acetate ions. Moore and Kraus (199) have separated cobalt and nickel in hydrochloric Y
Developments of new ion exchange materials and techniques have followed well-defined patterns. So-called electron exchange
ANALYTICAL CHEMISTRY
106 acid solutions ubing strong base anion exchangers. D'Ans and Blasius ( 8 ) have employed resins for the separation of cobalt and chromium salts. T h e separation of the cation complexes of chromium thiocyanates has been investigated by King and Disniuker (156). Similar studies have been reported by Samuelson (238) and by Yoshimo (310) for the separation of arsenic from iron. Rieman and Tendenbaum (225) have used strong base anion exchange resins for the separation of chlorides and bromides. Muto (204)removed interfering cations prior to a basic acid determination. Kraus (163) studied the anion exchange separation of the transition elements from manganese to zinc. He also examined separation of sulfuric acid from metal sulfates (165). A similar study was made on hydrochloric acid adsorption on strong base anion exchange resin (162). Interfering phosphates mere removed by anion Pxchange resins prior to a calcium determination (42). ORGAYIC SEPARATIONS
T h e application of ion exchange resins has become routine for the purification and separation of the components obtained from various biological systems. Ion exchange resins have been used extensively for the fractionation of amine acids from various sources (2-4, 9, 11, 13, 25, 34,38,39, 45,53,54, 56, 67, 78, 98, 102, 113, 114, 121, 129, 131, 136, 152, 172, 194, 198, 215, 216, 226, ,234,256, 265, 266, 270, 272, 276, 282, 283, 291, 306, 313). Carsten (53, 54) and Stein (266) made complete analyses of the amino acid separations, while Baker ( 1 3 ) employed the technique for enzymatic resolution of proteins. A comparison of variouq methods of purification has been made by Sanger (242) Hirs (118) has employed volatile buffers to facilitate the concentration of the ion exchange fractionated amino acids. [Studies of nucleic and ribonucleic acids have employed ion exchange fractionation of these complex systems (26, 66. 68, 74. 76, 89, 103, 107, 116, 119, 128>183, 185, 187, 295, 232, 248) 275, 290)l. Dinucleotides were resolved after separation from monucleotides (153, 184, 186, 264, 260). hdenosine phosphates obtained from yeast have been studied b y means of ion exchange (6, 18, 27> 79, 80, 136. 150, 154, 202, 203, 253, 257, 312). Hydroxyproline, proline, and peptides were isolated and fractionated from collagen (152, 167). Lysozyme v. as fractionated on carboxylic cation exchange resins (249, 273). Purines, pyrimidines, polypeptides, and other nitrogenous materials were studied by ion exchange (242, 173, 241, 268, 293). Bacterial metabolic products \%erealso prepared for qtudy after an ion exchange treatment (115). The effect of electrolytes on the hydrolysis of urea by urease was examined by Kistiakowsky et al. (1~78~ 159). Pantothenic acid in urine has heen determined after ion exchange chromatographic separation (18,70). Erythrulose phosphate and other metabolic products were purified by exchange treatment (60, 138, 144,261). Gardell ( 9 6 ) used a (sation exchanger for the separation of glucosamine and galactosamine. A weak base exchanger was used by Salmon (236) in order to concentrate I-ascorbic 1-Cl4 acid. Serine and qarcosine (197), cytochrome (50, do?), and pipecolic ac4d (200. 311) have been purified and isolated b y ion exchange. Chlorogenic acid was isolated from apple fruit by Hulme (134). Roseman et al. (250) employed ion exchange to remove interfering ions during the biosynthesis of hyaluronic acid. Rosenberg (2311 employed ion exchange to iqolate a growth factor from chicken tissue Exchangers were used to decolorize plant extracts (247) and to isolate porphobilinogen from urine (297). Degradation products from amylopectin ( 2 7 7 ) ,inosital phosphates (259), and hypoxanthine and inosine acid (252) were fractionated and isolated by means of ion exchange. Pituitary hormones have been purified by ion exchange techniques (169, 181, 221, 225, 300). Xanthople-6,7-C11 has been fractionated and purified by Dixon ( 7 9 ) and Anher and Boehne ( 7 ) . Xylose has been isolated from a n enzymatic reaction by strong base anion exchange resins (120). Polysaccharides were subjected to a n ion exchange treatment prior to isolation by Hough (130) Khym and Zill (155) qtudied
the separation of sugars on strong base anion exchangp resirt.. Windsor (304) studied the separation of aminoadipic acid. MISCELLANEOUS ANALYTICAL APPLICATIONS
Ion exchange has been applied to a variety of miscellaneow analytical problems in recent years. Jindra et al. (139-141) hwvc employed ion exchange for the determination of sulfamides, sympathomimetric amines, and antihistaminics. Mot1 (201) urcd strong base ion exchange resins for the determination of atebrinr. Narcotics were evaluated by Levi and Farmils (179) and Hilty and Grant (10.4). Yampol'skaya (308) developed methods for the determination of a wide variety of pharmaceutical prepaixtions using cation exchangers. Bucki and Furrer ( 4 8 ) devised :ti1 analytical method for the determination of alkaloids. Ergothioneine was measured in blood by strong base anion exchange resiii? (193). McCoy (189) applied exchangers t o water anal Samuelson et al. ( 5 , 93, 94, 112) developed analyt'ical methods for the separation of aldehydes and ketones from acids and alcohols in the determination of formic acid in the presence of fornialdehyde, and also studied the effect of oxidizing agents on ion eschange materials. Samuelson and Schramm (240) and Syllmann ( 2 7 1 ) developed a method for measurement of total salt concentration which employed strong base anion exchangers. Oda et al. (210,211) and Parkinson (213) used ion exchange to separate and concentrate vitamin B prior to analysis. Steinback and Freisse (267) and Greenbaum et al. (105) have w e d an anion exchanger to prepare standard caustic solutions. Salts in organic acids and bases (12) and microanalysis of the salts of organic' acids (284)have been determined using cation exchange resins. Sweet et al. (269)have used exchangers for the determination of alkali metals in insoluble silicates. Ammonia and magnesium in urine are separated and concentrated on cation exchange resin prior to their estimation (309). Boron analysis may be fwilitated by means of ion exchange (44)192). Galacturonic acid determination by ion exchange techniques has become a stanclard procedure (305). Vitamin aesays have been improved by various ion exchange techniques (246, 295). Sugars and carbohydrates have been isolated and analyzed by cation (262) and anion exchangers (20, 58, 59, 1-56, 208, 209, 220, 228, 229, 307, ,914). Various plant extracts and flavors have been concentrated and isolated on carboxylic cation exchange resins (137, 14.3, 501 -503). Gums have been purified by deionization in order to remove acids and bases ( 1 ) . Nitrogenous extracts of haddock were fractionated by Shewan et al. (255). T h e reaction products from the parboxylation of resorcinol (110) were separated on strong bas? anion e x h a n g e resins. Coenyzme h was purified on similar resins (264). Antibiotics were studied by ion exchange methods (180, 2.58, 185). Medicinal preparations are described which make use of ion exchange fractionation (313). h direct met'hod for the determination of acid-base relationships in blood sera has employed cation exchange resins ( 8 4 ) . Gaudie and Rieman (97) and Kubo and Tsutsumi (168) have suggested an ion exchange tevhnique in the determination of phosphates. Honda (125) has described the preparation of indicating resins for p H studies. Methods for the preparation of laboratory columns have also been described (19, 21, 43). Several proretlures for sulfate determination have been suggested (92, 12;. 148, 206). T h e application of exchange to measurement of total acidity or basicity of solutions has been discussed (176, 1?Yj 190). Copper has been determined in mineral oils by concentration on cation exchangers (46). T h e adsorption of inorganic salts from solvents was studied by Katzin (149). Blasius and Wachtel ( 2 4 ) detected polar pyridine iodide complexes by their cation properties. Disposal of radioactive cations from waste solutions was investigated using cat'ion exchangers (99). High purity hydrogen peroxide was prepared by cation exchange (83). Special deionization procedures for blood sera employing mixtures of exchangers have been described ( 8 6 ) . Tl'einstock and Boekelheide (294)
V O L U M E 2 6 , NO. 1, J A N U A R Y 1 9 5 4 employed basic exchangers as catalyst for Hofmann de‘gradation reactions, thereby simplifying analytical procedures on the products. Electrometric titration of chloride may be improved by using a half cell containing a hydrogen-silver exchange resin (100). SanQoni (2.d.3) has studied oxidation-reduction reactions on exchanger beds. A “zebra” column consisting of layers of virious types of exchangers has been found useful for the preliminary evaluation of unknown solutions (122). Schubert (250,261)has reported on the determination of complex stability liy use of ion exchange techniques. Excess acid has been removed by ion exchange prior to analysis (87). Waldock (296) has determined the infrared structure of several functional groups in ion exchange polymers. ACKNOWLEL)(;hIENT
The authors wish to acknowledgr the assistance of Helen Tucker and the l i b r a y staff of the Rohm & Haas Co. for their aid in obtaining and assembling the many srticles reviewed in this papev. REFERENCES
(1) .Xbdel ..ikher, RI., Smith, F., and Spriestersbach, D
SOC., 1952, 2637-3640. ( 2 ) ;Ibelson, P., Bolton, E . , and -4ldo1is. E., J . Biol. Cheni., 198,
165-72 (September 1952). (3) Ibid., pp. 173-8. (4) Ahrams, A , , and Boi,sook, H., Ibid., 198, 205-14 (September
1952). (5) Ahlen, L., and Samuelson, O., AX.LL.CHEM.,25, 1263-4 (1953). (G) Alberty, R., Smith, R.. and Roch, R.. .J. B i d . Chem., 193, 425-
34 (1951). ( i ) .4tiher, R., and Borhne. T . , J . A m . Chem. SOC.,74, 2431-2
(1952). (a) d’Ans, J., and Blasius. I:.,Salir).21.iSSc,iischuften, 38, 238 (1951). (9) -lqvist, S., Acta i . Scarrd., 5, 1031 4 5 (1951). (10) .%i.gersinger, W .and ~ Dayidson. A., J . Phys. Chem., 56, 92--6 (January 1952), (11) .iusterweil, G., and De1oi.t-Stechrnko, ,J., Compt. rend,, 235, 12524 (Kovemher 1952), (12) Raggesgaard-Rasmusser!, IT., Furhs, D., and Lundery, L., J. P h a r m . and Phnrnincol., 4, 566-72 (1952). (13) Baker, C., and Sober, H., J . Am. Chern. Soc., 75, 4058 (1953). (14) Harendregt, F., and Torn. S., Pkysicu, 17, 817-20 (September 1951). (15) Basinski, A., Wiadorrro&i C h e n i i . , 5, 133-52 (1951). (16) Rauman, W.,Anderson, R., and Wheaton, R., A n n . Ret,. P h y s . Chem., 3, 109--30 (1953). (17) Baunian, W., and lIcKellar, K., U. S. Patent 2,614.099 (Oct. 14, 1952). (1‘) Hendich, A,, Russell, P., and I3rown, G., J . B i d . Chem., 203, 305-18 (July 1953). (19) Bennett, O., .VucZeonics, 10, 14-18 (February 1952). (20) Rergman, W. E. (to Phillips Petroleum Co.), Ibid., 2,617,800 (Xov. 11, 1952). (21) Berne, E . , Acta Chem. Scand., 5, 1260-6 (1951). (22) Betts, R., and LIacKenzie, -I.,Can. J . Chem., 30, 146-62 (February 1952). (23) Blasius, E., Angeu,. Chrni., 65, 348 (July 7, 1953). (24) Blasius, E., and Wachtel, U.,Z. anal. Chem.. 138, 106-10 (1953). (25) Block, R., Stekol, J., and J.oosli. J., Arch. Biocheni. u n d Biof i h ~ s . 33,353-63 , (1951). ( 2 6 ) I3oardman, K., and Partridge, S., .Yut7m3. 171, 208-10 (January 1953). ( 2 7 ) Bock, R., and Alberty, R., .I. Biol. Chem., 193, 435-42 (1951). (28) Bodamer, G., Can. Patent 493,041 (;\lay 19, 1953). (29) Ibid., 493,562 (June 9, 1953). (30) Ibid., 493,563 (June 9, 1953). (31) 13onner, 0. D., Argersinger, W. J., Jr.. and Davidson, A . W . , J . Am. Chem. Soc., 74, 1044-7 (1952). (33) Ibid., pp. 1047-50. (33) Ronner, 0. D., and Rhrtt, X-., ,I. P h y s . Chem., 57, 254-G (February 1953). (34) Jhstrom, H.. and Aqvist, S.,l c t a Chem. Scand., 6, 1557-9 (1952). (8.5) Boyd, G. E., Ann. Rev. P h y s . Chem.. 2, 309-42 (1951). (36) Boyd, G. E., and Soldano, B., 2. Elektrochem., 57, No. 3, 16272 (1953). ( 3 7 ) ]I., J . Am. Chem. Soc., 75, 1244-5 (1953). Cohn, W., and Volkin, E., J . B i d . Chem., 203, 319-32 (July 1953). Conellakis, E., and Tower, H., Arch. Biochem. and B i o p h y s . , 42, 446-55 (1953). Covalieri, L. F., J . A m . Chem. Soc., 73, 4899-902 (1951). Crokaert, R., Moore, S., arid Bigwood, E., BuZZ. SOC. chim. bioi., 33, 1209-13 (1951). Crokaert, R., Moore, S., and Bigwood, E., Chimia (Switz.),5, 284 (1951). D’iilelio, G., U. S. Patent 2,644,801 (July 7, 1953). Ibid., 2,645,621 (July 14, 1953). (73) Daul, G., and Reid, Ibid., 2,610,953 (Sept. 16, 1952). (74) Daus, L., lleinke, M., and Calvin, M., J . B i d . Chem., 196, 77-87 (1952). Davies, C., and Jones, T., J . Chem. Soc., 1951, 2615-24. Dekker, C., Michelson, d.,and Todd, -4., Ibid., 1953, 947-56. Deuel, H., Hutschneler, K., and Solms, J., 2. Elektrochem., 57, 172-8 (1953). Dimant, E., Smith, V., and Lardy, H., J . Bid. Chem., 201, 85-91 (March 1953). Dixon, H., Moore, S., Stack-Durne, M., and Young, F,, S u t u r e , 168, 1044-5 (1951). Dulberg, S., Roessler, IT., Sanders, T., and Brewer, G., J . BzoZ. Chem., 194, 199-213 (1952). Duncan, J., Nature, 169, 22-4 (1952). Duncan, J., Proc. Roy. SOC.( L o n d o n ) , 214A, 344-55 (September 1952). E. I. du Pone de Kemours h Co., Brit. Patent 695,325 (Aug. 5, 1953). Epshtein, L., Biokhirniya, 16, 572-8 (1951). Ezrin, AI., Updegraff, I., and Cassidy, H., J . A m . Chem. Soc., 75, 1610-14 (1953). Farbenfabriken Bayer, Ger. Patent Applic. PA 102,688 (Oct. 23, 1952). Fishell, J., DeLong, W., and Oliver, K., Can. J . Chem., 30, 9-16 (January 1951j. Fisher, S..and Jleloche, V., A s . 4 ~ .CHEX.,24, 1100-6 (1952). Flavin, M., and Engelman, M., J . B i d . Chem., 200, 59-68 (January 1953). Freund, H., and Miner, J., ANAL.CHEM.,25, 564-7 (1953). Fronaeus, S., Acta Chem. Scnnd., 6B, 1200-11 (1952). Funasaka, Wataru, Kawane, IIakoto, and Hashino, Tomoyasu, J . Chem. Soc. J n a a n . I n d . Chem. Sect.. 54. 355-7 (19513. Gabrielson, G., and Samuelson, O., Acta Chem. Scand., 6 , 72937 (1952).
108 194) Ibid.,pp. 738-43. (95) Gapon, E., and Balenkaya, J., Zhltr. Priklad. Khim., 23, 141920 (1950). (96) Gardell, S., Acto C h c n ~Scand., . 7, 207-15 (1953). (97) Gaudie, -4., and Rieman, W., ANAL.CHEM.,24, 1067-8 (1952). (98) Gilvary, C . , and Block, K., J . Bid. Chem., 193, 339-46 (1951). (99) Ginell, W. s.. LT. S.Patent 2,616,847 (Nov. 4, 1952). (100) Glueckauf, E., Proc. Royal SOC.(London), 214A, 207-25 (August 1952). (101) Goddall, R.. and iilellor, N., A n a l . Chim. Acta, 6 , 373-8 (1952). (102) Goldthwait, D., and Rendich, A., -1.B i d . Chem., 196, 841-52 (1952). (103) Goldwasser. E., Snture, 171, 126-7 (Jan. 17, 1953). (104) Grant, E., and Hilty, W., J . Am. Pharm. Assoc., 42, 150-2 (1953). (105) Gieenhaum, B.. Schoniger. W., and Kirk, P., ANII.. CHE\I., 24, 1857-8 (1952). (106) Greaor, H., Taifer. 31.. Citarel. I,., and Recker. E.. I n d . E n o Chml., 44, 2834-9 (1952). (107) Groth, D., Mlueller, G., and LePage. G.,,J. BioZ. Chem.. 199, 389-91 (Sovember 1952). (108) Grunhaum. R.. and Kirk, P.. Mikrochen7ie rer. Mikrochim. Acta. 40, 416-20 11953). (109) Guthrie. ,J. D.. I n d . Eng. Chem., 44, 2187-9 (1952). (110) Hale, D., Hnwdon, A , , Jones, J., and Packham, D., 6.Chem. Soc., 1952, 3503-9. (111) Hale, D . , Packham, D . , and Pepper, R.. Ibid., 1953, 844-51, (112) Hartler. S . , and Samuelson, O., Anal. Chin,. Acta, 8 , 130-3 (1953). (113) Haskell, T., Fusari, S., Frohardt, R . . and Barts, R . , J . A m . C h m . SOC..74, 599-602 (1952). (114) Haworth, R . , AZacGilliway, R., and Peacock. D., J . C h m . Soc.. 1952, 2981-7. (115) Hayaish, O., and Kornherg, 4.. * J . B i d . Cheln., 197, 717-32 (1952). (116) Henrick. AI., Dewey, V.. Parks, R.. and Kedder, C , Ihid., 197, 199-204 (1952). (117) Hering, H., A n a l . Chiin. Acttr, 6 , 340-50 (1952). (118) Hirs, C.,Uoore, S., and Stein. IT,, ,J, B i d . Chew.. 195. 669-83 (1952). (119) Ibid., 200, 493-506 (19533. (120) Hochstes. R . , and TTatson, R., J . .4m. Cheni. Soc., 75, 3284-5 (1953). (121) Hogstrom, G.. Acta Chem. Scand., 7, 45-50 (1953). (122) Holm, L., Research (London), 5, 286-8 (1952). (123) Honda, AI., J . Chem. Soc. . J a p a n , Pitre Chem. Sect.. 72, 3 6 1 4 (1951). (124) Ihid., pp. 555-9. (125) Ibid.,pp. 638-41. (126) Ibid., 73, 529 (1952). (127) Honda, 31., Yoshino, Y . , and Wabiko, T.. Ihid., 73, 358-9 (1952). (128) Horecker. B., Smyrniotic, P., and Seegmiller. S.,J . B i d . Chem.. 193, 383-96 (1951). (129) Horowits, H., Doerschuk, -4., and King, C., Ibid., 199, 193-8 (November 1952). (130) Hough, L.. Jones, J., and Wadman. H., 1. Chem. Soc.. 1952, 3393-9. (131) Housmann. W., and Craig, L., .J. Biol. Chem., 197, 405-19 (September 1952). (132) Howard, J.. J . Am. Leather Chemists' Assoc., 46, 654-9 (1951). (133) Huffman, E., and Iddings, G.. J . A m . Chem. Soc., 74, 4714-15 (1952). (134) Hulme, A., Biochem. J . ( L o n d o n ) , 53, 337-40 (1953). (135) Hulme, d.,and .4rthington. TV.,Y n t w e , 170, 659-60 (Oct. 18, 1952). (136) Hurlbut, R., and Potter, I-.,1. Bid. Chem., 195, 257-70 (1952). (137) Ice, C., and Wender, S.,J . A m . Chem. Soc., 75, 50-2 (1953). (138) Jensen, J., Durhane, W., and Pearce, G., Arch. I n d . Hug. and Occupational Med., 6, 326-31 (October 1952). (139) Jindra, A , , and Motl, O., 6eskosZov. Farm., 1, 632 (1952). (140) Jindra, A , and Renta, J., Ibid., 1, 625-30 (1952). (141) Jindra, A., and Sipos, F.. Chem. L i s t y , 44, 235-8 (1950). (142) Jolles, F., and Fromagent, C., Biochim. et Biophys. Acta, 11, 95-101 (May 1953). (143) Jones, 3. K . X., and Wise. L., J . Chem. Soc., 1952, 3339-93. (144) Jorpes, J., and Mutt, V., Nature, 172, 124 (July 1953). (145) Kagawa, I., and Kasashi, R., J . Chem. SOC.J a p a n , I n d . Chem. Sect., 54, 242-4 (1951). (146) Kakihana, H., J . C h a . Soc. J a p a n , Pure Cheni. Sect., 72, 200-3 (1951). (147) Ibid., pp. 255-8. (148) Kakihana, H., and Yashiro, K., J a p a n . Analyst, 1, 85-6 (1952). (149) Katsin, L., and Gebert, E., J . Am. Chem. Sac., 75, 801-3) (1953).
ANALYTICAL CHEMISTRY (150) Kdinedy, E., J . B d . C h e m . . 201, 399412 (March 1953). (151) Kenoshita, J., and Bull, E., Ihitl., 200, 609-17 (February 1953). (152) Khym, J. X., and Cohn, IT., J . Ana. Cihem. Soc., 75, 1153-6 (19.53). (153) Khym, J. X., arid Doherty, D. G . , Ibid., 74, 3199-200 (1952). (154) Khym, J. X., Doherty, D. G., Polin, E., and Cohn, W,, Ihid., 75, 1262-3 (1953). (155) Khym. J. X., and Zill. L.. I b i d . , 74, 2 0 9 0 4 (1952). (156) King, E., and Disninker, E., Ibid., 74, 1674-5 (1952). (157) King, E., and Walters, R.. Ibid.,74, 4471-2 (1952). (158) Kistiakou-sky, G., .\Iangelsdorf, P., Rosenberg, A , , and Shaw-, W., Ibid., 74, 5015-20 (1952). (159) Kistiakowsky, G., and Rosenherg. .4., Ihid., 74, 5020-5 (1952). (160) Klement. R., 2. anal. Chein., 136, S o . 1, 17-25 (1952). (161) Klyachko, V., Doklady Bltnd. S a u k S.S.S.R.,81, 235-7 (1951). (162) Kraus, K., and Iloore, G.. .I. &4n~. Chem. Soc.. 75, 1457-60 (1953). (163) Ihid., pp. 1460-2. (164) Kraus, K.. and Nelson, F.. Ihid., 75, 3273-4 (1953). (165) Kraiis, K., Nelson, F., and Jhxter, S., Ihid.. 75, 2768-70 (1953). (166) Kressnian, T., Mfg. Chrminf. 23, 93-5, 98 (1952). (167) Kroner. T., Tahroff, IT.. AIcChrr, J., J . Sin. Cheni. Soc., 75, 4084-6 (1953). (168) Kuho. S.. and Tsutsunii, C . , Brill. Chew. Soc. J o p a t i . 23, S o . 5, 187-9 (So\-emher 1930). (169) Iiuehl, F.. .\leisinger, .\I,,131 ink, S . , t t t i d Folkeru. K., J . A m . Cherji. SOC..75. 1955-9 11953). (170) Kuhn, W.,Hargitay. B., Katc.halsky, -1.. arid Eiuenberg, H , , dYftture,165, 514 (1950). (171) Kunin, R., and .\IcGarwy, I?., I n d , Eur]. C h m . . 45, 83-8 (1953). (172) Lnbbe. E.. Thomyson, R..Cheldelinc, C.. and Wong, C . , J . B i d . Cheni., 197, 655-61 (1952). (173) Lagerhist. U., .4cta Chevi. S c n i c d . . 7, Il4--18 (19533. (174) Leden. J. I . , J . B i d . (183) Loring, H., Rortner, H., L
Chem.. 196. 807-9 (1952). (184) Loring. H.. Fairly. .J.. Rortnrr. H.. nnd .Seagram. H., Ihid., 197, 809-21 (1952). (185) Loring, H.. Fairly. .J., and S e n w n m , R.,Ibid., 197, 823-30
(1952). (186) Loring, H., Hammell, AI.. I.ely, L., and Rortner. H., Ibid.,
196, 821-8 (1952). (187) Lowry, B., Davoll, J . , and Brown, G. H., l b i d , , 197, 591-600 (1952). (158) Luigi, M., Atti accad. nazl. Lincri, Rend. C ' l o . ~ECI' .is. mot. e nat., 11, 80-5 (1951). (189) lIcCoy, J., Anal. Chini. Actri, 6 , 259-66 (1952). (190) XIarconi, M., Chimica (MiZan), 6, 384-5 (I951 1 . (191) Ibid., 7, 432-3 (1952). (192) IIartin, J.. and Hayes, J., .LTIL. C H m r . , 24, 182 (1952). (193) Melrille, D., and Lubsches, R., J . B i d . ChPm., 200, 275-85 (Jannary 1953). (194) Nerck and Co., Brit. Patent 692,922 (June 17, 195:3j. (195) AIerrifield, R., and TVoolley. D., J . Bid. Chem.. 197, 521-37 (1952). (196) Mnami, E., Kakihana, H., and Fuzimoto, 31.. 6.( ' h e m . SOC. J a p a n , Pitre Chem. Sect., 73, 368-70 (1952). (197) Nitonia, C., and Greenhcrg, D., J . B i d . Chenc.. 196, 599-614 (1952). (198) Moldare, K., Wingler, R., and Pearson, H., Ibid.. 200, 357-65 (January 1953). (199) Moore, G., and Kraus, K., ,I. Bm. Cheni. Soc., 74, 8 4 3 4 (1952). (200) Morrison, R., Biochem. J . (London), 53, 474-8 (1953) (201) hlotl, O., Ceskosloc. F a ~ r n . ,1, 630-2 (1952). (202) Munts, J., Arch. Biochem. and Biophys., 42, 435-45 (1953). (203) hluntz, J., J . Biol.Chem., 201, 221-33 (>larch 1953). (204) RIuto, S..J . Cheni. SOC.Japan., Pure Chem. Sect., 72, 976-9 (1951). (205) Mysels, K., Science, 114, 424-5 (1951). (206) Nakanishi, H., and Nagas, S.,Japan. Analyst, 1, 8€7(1952). (207) Neilands, J., J . Bial. Chem., 197, 701-8 (1952). (208) Ness, R. K., and Flet,cher, H., J . Am. Chem. SOC.,74, 5341-3 (1952).
V O L U M E 2 6 , N O . 1, J A N U A R Y 1 9 5 4 Soggle, G., and Zill, L., Arch. Biochem. and B i o p h y s . , 41, 21-8 (November 1952). Oda, R., and Shimisu, H., Chem. High Polymers ( J u p o r i ) , 8 , 142-5 (1951).
Oda, R., Shimizu, H., and Yamanaka, T., R c p t s . I n s t . Chem. Reseaich, Kyoto Unit,., 16, 42-3 (1947). Osborn, G., Analyst, 78, 220-52 (April 1953). Parkinson, T., Chemistry & Industry, 1952, 17-18. Partridge, S. M.,Nature, 169, 4 9 6 7 (1952). Partridge, S. M.,and Brimley, R. C, B i o c h ~ m ..I. ( L o n d u n ) , 51, 628-39 (1952).
Partridge, S. M., Intern. Congr. Biochem. Ahstr. Coinnmns., 1st Congr., Cambridge, Enol., 1949, 137-9. Pepper, K.. Plastics Inst. (London). Trans.. 20, 68-84 (July 1952).
Pepper, K., and Reichenberg, R., 8. Elcktrochem., 57, 183-8 (1953).
Pepper, K., Reichenberp, R., a n d Hale, D , J . C h e m Soc., 1952, 3129-36.
Phillips, J., and Pollard, :I., S a f u r e , 171, 41-2 (.Jan. 3. 1953). Pierce, J., Gordon, S., and Vignrand, V. du, J . Biol. C h ~ m . , 199, 9 2 9 4 0 (December 1952). Radhahishna. P. B.. dnrrl. Chin!. Acto, 6, 351-4 (1952). I b i d . , 8, 140-5 (1953).
Richter, .J.. .I+er, D., Rozemorr. -1..Brink. S . . and Folkers, K.. J . .lm. Chem. S’oc.. 75, 1952-5 (1953). Ilienian. W., and Tendenbaum. S.,.~S‘AI..CHEII., 24, 1199-200 (1952).
Patent 2.590,209 (Ilarch 25, 1952). Roberts, T., Willeford. B., and ;\lherty. R., J . Chem. Edicc.. 29, 542-8 (1952).
Roseninn. 9...J, A m . Chcm. Soc., 74, 4467--8 (1952). Roseman, S.. .ibeles. R.. and Dorfman, A . . drch. Biochem. and Riophys., 36, 232-3 (1952). Roseman, H.,Moses. F., Ludowiez. .J.. and Dorfman. .I..J . B i d . Chcn2.. 203, 213-25 (July 1953). R o s e n h r g , S.. and Kirk. P., Arch. Riochr,r?z.rind B i o p h y ~ . .44, 22li-9 (1953).
Rowen. .I., and Kornherg, .L, J . Riol. Chem.. 193, 497-507 (1 951j
.
Rynhchikov, D. I., and Rukhitiarov, V. E . , Zh7rr. Anal. Kliini., 7, 377-83 (1952).
Snltladze, K . , Doklndy d k n r l . Sniti; S.S.S.R., 77, 457-60 (1951). Salmon. J.. and Tietve. H.. J . Chwn. S o c . . 1952. 2324--6. Salmon; I,., Burns, :J., and King. C’.,,J. A m . Chenl. Soc., 74, 5161-2 (1952).
Saniuelsom 0.. “Ion Exchange in Analytical Chemistry.” S e w Tork, .John Wiley & Sons. 1953. Saniuelson. 0.. Swnsk Kcm. Tirlskr., 63, So. 8, 183-93 (1951). Saniuelson. 0..Z. Elektrochem.. 57, 207-13 (1953) Saniuelson. O., and Schramm, K., S ~ c r i s k Kcm. Tidskr., 63, 307-11 (1051).
Sanper, F.. and Thompson, E., Biochem. J . ( L o n d o n ) . 53, 35374 (1953).
Sangcr, I.’., and Tuppy. €I., Ihid., 49, 463-81 (1950). Sansoni, R., Srrtir~iuissenschnftr,l,39. T o . 12, 281 (1952) Sasaki, T.. and Inaba?..I., Birli. C h e n ~ .SOC..lnprrn. 24, 20-4 (1951).
Saunders, L.. and Srivastova. I < , ,.I. C h r m Soc.. 1952, 2111-18. Schimizu. I T . , and Shiba, H...I. Cheni. SOC. . J a p a n , Picre Cheni. Sect., 72, 442-4 (1951). Schlnharh. H., a n d TIauschildt. P., A n n . Chem. .I~i.st!~s Liebigs, 577, ,i1-0 (.Iiily 1, 1952).
Schmidt, G.. Cubiles, R.. Zollner. S . , Hecht. L.. Strickler, N., Seraidarian, K., and Thomnihariser, S..J . B i d . Chem ., 192, 715-26 (1951). ~,
J . Am. Chem. Soc., 74, 5118-24 (1952). Schubert, J., J . Phys. Chem., 56, 113-18 (1952). ’ Schubert, J., and Lindenbaum, H., .J. A m . Chem. So$., 74, ’ Schroeder, W.,
,
3529-32 (1952). (252) Schulman, h f . , and Buchanan, J., J . B i d . Chem., 196, 513-26 (1952). (253) Secgmiller, ,J., and Horecker, B., Ibid., 194, 261-8 (1952). (254) Sensheimer. R., and Koerner, J., J . A m . Chem. Soc., 74, 283 (1952). (255) Shew-an, J., Fletcher, L., Partridge, S. A I , , and Brimley, R., C.. J . Sci. Food Agr., 3, 384-98 (September 1953). (256) Shulgin. 9., Lein, O., Gal, E., and Greenberg, D., J . Am. Chem. Soe., 74, 2427-9 (1952). (257) Siekevity, P., and Potter, V., J . Bid. Chem., 201, 1-13 (1953). (258) Smissman, E., Sharpe, R., Aycock, B., Van Tamelen, E., and Peterson, W., J . Am. Chem. SOC.,75, 2029-31 (1953). (259) Smith, D., and Clark, F., Soil Sci., 72,353-60 (1951). (260) Sober, H., Kegles, G., and Gulter, F., J . Am. Chem. Soc., 74, 2734-40 (1952).
109 (261) Solins. J., Deuel, H., and .Inyns-Wriss. L., Helu. C h i m . Acta, 35, 2363-7 (December 1952). 1262) Sowden. J.. J . Am. Chem. Soc.. 74. 4377-9 (1952). (263) Spedding, F., Fulmer, E., P o ~ ~ lJ., l ,Butler, T., and Yaffc, S., Ibid.. 73, 4840-7 (1951). (264) Stadtanan, E., and Kornberg, Ai.,J . Biol. Chem., 203, 47-54 (July 1953). (265) Steele, R., Ibid., 198, 237-44 (September 1952). (266) Stein, W., Ibid., 201, 35-58 (March 1953). (267) Steinback, J., and Freisse, S., . ~ N A L . CHEM., 24, 1027-8 (1952). (268) Strassnian, AI., and Weinhouse, S.,J . Am. Cheni. Soc., 75, 1680-4 11953). , I (269) Sweet, R., Rieman, W., and 13erikenkamp, J., ANAL.CHt:\r., 24, 952-5 (1952). (270) Swick, R., Buchanan, D., and Snkao, A, J . Bid. Chem.. 203, 55-61 (July 1953). (271) Syllmann, H., Klin. Wochschi ., 30, 185-6 (February 1952). Daft, F., and Baner, H., (272) Tabor, H., Silverman, AI., >Irkla. -I., J . Am. Cheni. Soc., 75, 756-7 (1953). (273) Tallan, H., and Stein, T V . , .I.B V J ~Chem., . 200, 507-14 (February 1953). (274) Tevebnugh, A, Iowa State Coil. J . Sei., 25, 367-8 (1951). (275) Thomas, E., Hershey, F., .kbbate, A., and Loofborrow, J., J . Biol. Chem., 196, 575-92 (1952). (276) Thompson, A. R., S u t u r e , 169, 495-6 (1952). (277) Thompson, A. R., and Wolfrom. 11. L., J . Am. Chem. Soc.. 73, 5849-50 (1951). (278) Tiselius, -I.,Endeaaoitr, 11, 5-1B (1952). (279) Tompkins, E. R.. Analyst, 77, 970-82 (1952). (280) Tronihe, F., and Loricrs. J.. Compt. rend., 236, 1567-9 (.lpril 20, 1953). (281) Ihid.. pp. 1670-2 (.ipril 27, 1953). ( 2 8 2 ) Turnel., R.. Pierce, J., and ilu T’igneaud, Lr., J . Biol. Chem., 193, 359-61 (1951). (283) I-nderwoorl, G.. and Deatherage. F., Food Research, 17, 425-32 (1952). (284) 1-an Etten, C..and Wiele, 31., .IsAI,. CHEM., 25, 1109-11 (1953). (285) Tan Tamelen, E., and Sniissnian, E., J . Am. Chem. Soc., 75, 20:31-~5(1953). (286) Vernieulen, T., I n d . Eng. Chem., 45, 1664-70 (1953). (287) Vernieulen, T., and Hoffman, E., I h i d . , 45, 1658-64 (1953). (288) Ciekery. R., .J, Chem. Soc., 1952, 4357-63. (289) Vickery. R., S a t u r e , 170, 655-6 (Ort. 18, 1952). (290) Vissei.. D., Rarron, G., and Belte. R., J . Am. Chem. Soc., 75, 2017-19 (1953). (291) 171ies,G . van der, Chem. T e e k b l u d , 48, 350-6 (1952). (292) Waldock, I
