tion for the entire nlolecule will, therefore, be the value of the absorption for a given group, multiplied by the number of w c h groups. The molar absorptivity, e , of polybutadiene a t a given wavelength, defines the number of groups and the numher average molecular weight. The above study could be extended to other soluble polymers and a combination of infrared and nuclear magnetic resonance should prove powerful tools in the study of polymer micro? t 1iic t ure. ACKNOWLEDGMENT
The authors thank D. K. George for the majority of samples used in this work and C. F. Ferraro and his group for running the number average molecular weights with the lIechrolab vapor lmssure osmometer. The senior author is also grateful to F. 1.’ Greenspan and 1). K. George for their valuable disc u 4 o n s concerning the synthesis and eposidation of polybutadiene polymers.
The authors thank FMC Corp. for permission and S. K. Reed for his encouragement to publish this work. LITERATURE CITED
(1) Bawn, C. E., Rubber Plastics Age 42, 267 (1961). (2) Bellamy, L. J., “IEfrared Spectra of
Comolex Molecules, Xethuen, London, *1954. (3) Binder, J. L., ANAL.CHEM.26, 1877 (1954); J. Polymer Sci. 1, 47 (1963). (4) Bovey, F. A., Tiers, V. G. D., Fortschr. Hochpolym. Forsch. 3, 139 (1963). (5) Bovey, F. A., Tiers, V. G. D., J . Polymer Sci. 44, 173 (1960). (6) Bovey, F. A., Tiers, V. G. D., Filipovitch, G., Ibid., 38, 73 (1959). (7) Chen, H. Y., AXAL. CHEM.34, 1134 (1962). (8) Diirbetaki, A. J., Ibid., 28, 2000 (1956). (9) Durbetaki, A. J., “Chemical Aspects of Oxirane Oxygen Analysis,” presented at 139th Meeting, ACS, St. Louis, Mo., AIarch 21-30, 196:; (10) Goddii, R. F;, h e a r Infrared Spect rophotomet ry, Advances in hnalytical Chemistry and Instrumentation, pp. 347-424, Interscience, New York, 1960.
(11) Greenspan, F. P., Pepe, A. E. (to F X C Corp.), S.Patent 3,030,336. (12) Hampton, R. R., ANAL.CHEM.21, 923 (1949).
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(13)Jackman, L. M.,“Nuclear Magnetic Resonance Spectroscopy,’’ Pergamon Press, New York,((l960. (14) Kline, G. AI., Analytical Chemistry of Polymers,” Part I, pp. 133-5, Interscience, New York, 1961. (15) Ibid., Part 11, pp. 291-333, 1962. (16) Kraus, G., Sohort. J. N.. Thornton. V., Rubber Plastzcs Age 10, 880 (1957). (17) Natta, Ginlio, Ibzd., 10, 485 (1957). (18) Pollock, D. J., Elyash, L. J., DeWitt, T. W., J . Polymer Sct. 15, 87 (1955). (19) Pople, J. A., Schneider, W. G., Bernstein, H. J., “High Res,$ution X d e a r Nagnetic Resonance, >ICGraw Hill, Sew York, 1959. (20) Richardson, W. S., J . Polymer Sci. 13. 229 (1954). (21) ‘Rose,‘F. W’., Jr., J . Res. Natl. Bztreau Std. 20, 129 (1938). (22) Schmaltz, Schmaltz, E. O., Geiseler. Geiseler, G. L.. L., 2. Anal. Chem. 190, 293 (1962): (1962). (23) Silas, R . S., Yates, J., Thornton, V., AXAL.CHEM.31, 529 (1959). RECEIVED for review November 27, 1964. Accepted July 12, 1965. Division of Analytical Chemistry, 145th hleeting, ACS, New York, S . Y., September 1963.
Liquid-Liquid Extraction of Metal Ions from Aqueous Solutions of Organic Acids with High-Molecular-Weight Amines The Triva lent Actin ide-La ntha nide Elements FLETCHER L. MOORE Analytical Chemistry Division, Oak Ridge National laboratory, Oak Ridge, Tenn, N e w liquid-liquid extraction systems for the trivalent actinide and lanthanide elements are described. Highmolecular-weight amines are excellent extractants for anionic complexes of these elements from aqueous solutions of most organic acids. Liquid-liquid extraction behavior is described for the acid systems-citric, tartaric, oxalic, (ethylenedinitri1o)tetraacetic (EDTA), ahydroxyisobutyric, and acetic-with various primary, secondary, tertiary, and quaternary amines. The high extractability of the anionic EDTA complexes of trivalent actinide, lanthanide, and other metal ions from both acid or alkaline solution is of considerable practical importance. In the actinide-lanthanide series the order of decreasing extractability is americium, curium, californium europium samarium promethium cerium yttrium thulium. Several potential applications for the separations chemist are discussed.
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interest has developed recently in discovering better separation methods for the trivalent actinide and lanthanide elements; both OXSIDERABLE
inter- and intragroup separations are needed. Liquid-liquid extraction methods hold much promise for solving some of the current problems in the actinide-lanthanide element field. Several workers ( 1 , 4-6) have cited the problems and described new solutions to some of them. A11 the previous systems utilized extractions of metal inorganic complexes, such as nitrate, chloride, or thiocyanate. The trivalent actinide and lanthanide elements form their strongest compleses with the organic ligands, such as citrate, tartrate, osalate, (ethylenedinitril0)tetraacetate (EDT-I), and a-hydroxyisobutyrate. This fact renders them inestractable with the commonly used solvents -alcohols, ketones, chelating agents, organophosphorus compounds. Recently the writer discovered a new area of considerable potential -1iquidliquid estraction of the trivalent actinide and lanthanide elements from aqueous solutions of organic acids with highmolecular-weight amines. This intriguing possibility, previoualy unexplored, of effecting valuable separations based on differences in anionic organic ligand complexes prompted a
preliminary investigation of several systems. I n this paper early results are described with some typical actinidelanthanide and miscellaneous metal ions in aqueous systems containing the organic acids, citric, tartaric, oxalic, EDTA, a-hydrosyisobutyric, and acetic. A primary purpose is to describe the great potential of these new systems, which estend the scope of liquid-liquid estraction considerably. EXPERIMENTAL
Apparatus. S a 1 (Tl) well-type gamma scintillation counter, 1 3 / 4 x 2 inches. Interchangeable aluminum and lead absorbers (1.88 inches high, 0.75inch o d . , and 0.4-inch i d . ) were used for selective counting. Internal methane flow proportional counter. Alpha counting x a s done at 2900 volts, beta counting a t 4300 volts. Reagents. Priniene J l I - T is a mixture of primary amines, principally in the C18-22 range. Primene 81-R is a mixture of primary amines, principally in the C12-14 range. Xmberlite L-4-1 (S-dodecenyltrialkylmethylamine) and Xmberlite LA-2 (S-lauryltrialkylmethylamine)are secondary amines. These secondary amines and the primary amines listed VOL. 37, NO. 10, SEPTEMBER 1965
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above are readily available from Rohm and Haas Co., Philadelphia 5, Pa. Alamine 336-S (tricaprylamine) is a tertiary amine available from General Mills, Inc., Kankakee, Ill. Aliquat 336-S (tricaprylmethylammonium chloride) is a quaternary amine chloride available from General Mills. Reagent grade xylene and methylisobutylketone (hexone) were used for appropriate dilutions, which were stored in glass bottles. Procedure. Five milliliters of t h e indicated aqueous phase was extracted a t room temperature with a n equal
volume portion of the various solvents in 50-ml. heavy d u t y glass centrifuge tubes. Two-minute mixing periods were selected arbitrarily. High speed motor stirrers equipped with glass paddles were satisfactory for the extractions. After extraction, the tubes were centrifuged in a clinical centrifuge for 2 minutes. Each phase was then analyzed for americium*41 and europ i ~ m ' 5 ~by- ~counting 1-ml. aliquots in a well-type gamma scintillation counter. The weak americiumZ41 gamma ray (0.0596 m.e.v.) is completely absorbed in the lead absorber used while the
Extraction of and E u r o p i ~ m Tracers ~ ~ ~ - ~ from 0.01M Nitric Acid-0.2M Citric Acid Solution with Various Amines Tracer extracted, 7, Amine Diluent Am241 Eul52-4 Remarks 2094 Primene Jhl-T Xylene >99.9 99.6 Xylene (T) Excess miscibility ;99.9 >99.9 Hexone Hexone (T) >99.9 93.9 20Yc Primene 81-R Xylene >99.0 >99.0 Two organic phases Xylene ( T ) ... , . . Excess miscibility Hexone 99.9 99.8 Hexone (T) .. , .. . Excess miscibility Xylene >99.9 97.5 207, LA-] 55.5 53.8 Xylene (T) Hexone >99.9 99.0 Hexone ( T ) 21.9 21.2 2070 LA-2 Xylene 99.0 99.0 Xylene ( T ) 53.7 54.3 Organic gel Hexone >99.9 99.5 Hexone ( T ) ... .., Organic gel 207, Alamine 336-S Xylene 53.2 45.0 Xylene ( T ) 12.9 9.8 Hexone 95.4 89.6 Hexone ( T ) ... .,. Organic gel 207, Aliquat 336-S Xylene 1.2
