oxane system for the correction of quenching in determinations of C14, but was not so satisfactory as the use of a n internal standard in tritium assays.
comparable amounts of various biological compounds can be counted with the hyamine-water-dioxane system. Therefore, these two solvent systems were compared using H3-leucine. As shown in Table 11, the counting efficiency with the hyamine-water-dioxane system was comparable to that with the hyamine-toluene systcmm. The solubility of this particular amino acid was almost equal in solvents -1 and C, B and D, respectively, under t i e conditions employed. Sample prepitration was much easier and faster with the hyaminewater-dioxane system than the hyamine-toluene system. The former did not require the prolmged drying and digestion needed for the hyamine-toluene system. The ratio method ( 2 , 7 )was applicable to the hyamine-water-di-
LITERATURE CITED
(1) Bray, G. A., Anal. Biochem. 1, 279 (1960). (2) Bruno, G. A., Christian, J. E., ANAL. CHEX 33,1216 (1961). (3) Davidson, J. D., Feigelson, P., Intern. J . Appl. Radiation Isotopes 2, 1 (1957). (4) Hash, J. H., Anal. Biochem. 4, 257 (19621. -(5) Kidard, F. E., Rev. Sci. Instr. 28, 293 (1957). (6) Langham, W. H., Eversole, W. J., Hayes, F. N., Trujillo, T. T., J . Lab. Clin. Xed. 47, 819 (1956). \ - -
(7) Takahashi, H., Hattori, T., Maruo, B., Anal. Biochem. 2, 447 (1961).
(8) "Tri-Garb Liquid Scintillation Spectrometer Operation Manual," Packard Instrument Co., Inc., La Grange, Ill.,
1959. (9) Vaughan, M., Steinberg, D., Logan, J., Science 126, 446 (1957). (10) Werbin, H., Chaikoff, I. L., Imada, M. R., Proc. SOC.Exp. Biol. Med. 102, 8 (19593.
HAJIMETAKA HAS HI^ TOSHIE HATTORI BUNJIM m u o Institute of Applied Microbiology University of Tokyo Bunkyo-ku, Tokyo, Japan Present address, Laboratory of Radiation Genetics, Faculty of Agriculture, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Distribution of Ion Pairs between Immiscible Nonaqueous Solvents SIR: Few studies have been made of the suitability of nonE,queous immiscible solvent pairs for extIactive separations ( 1 , 3, 4 ) . This paLer summarizes in brief the estent to which different ion pairs distribute thems,elves in three such systems . EXPERIMENTAL
X commercial grade of formamide purified according t o T'erhocbk's procedure ( 5 ) w a b distilled under vacuum. Middle fractions t h a t had melting points greater t h a n 2.15" C. were obtained from numerous diqt llations and combined for use. Ethanolamine -cas repeatedly extracted with diethyl ether and then distilled. Only the fraction t h a t boiled between 169' and l i l O C. was collected. Adiponitrile, Eastinan White Label, Materials and Scdutions.
Table I.
Metal ion Fe(II1)
RZo(V1) hIO(V)
Cu(I1) SnlII)
Th(1V)
Extraction of ion Pairs from Diethyl Ether by Immiscible Nonaqueous Solvents
Associated anion
e1
Br SCN
e1 Br
scs Br c1 Br NO3 e1
Au(II1) Ce(1V)
IT03
Sn(IV)
c1 SCX
U(V1) co
m.p. 1' to 3' C., n'," 1.4382, was used without further purification. Prior to use, all three solvents were equilibrated with diethyl ether. All other materials were reagent grade. Aqueous solutions of the metal ions were prepared by dissolving that weight of a metal salt necessary to give a solution 0.04ilI in metal ion. Where needed, a minimum amount of acid was added to prevent hydrolysis. Apparatus. The extractions were carried out i n 125-ml. separatory funnels t h a t had carefully shaped short stems t o prevent holdup. Procedure. hfetal stock solution, 25 ml., was treated with appropriate reagents so t h a t t h e metal would be quantitatively extracted into ethere.g., t h e Fe(II1) solution was made 6 F in HCl. T h e ether phase was withdrawn, dried over CaC12, a n d equilibrated with a second immiscible phase.
NO3
Immiscible phase Ethanolamine Formamide Adiponitrile E
For the most part, the degree and direction of extraction could be satisfactorily estimated from the color of the phases. Where the ions were colorless, an appropriate analytical measurement was made. RESULTS AND DISCUSSION
The results of these experiments are shown in Table I. Only Sn(1V) showed a n y preference whatsoever for the ether phase. An attempt to neutralize the basicity of the amine was unsuccessful: the amine hydrochloride precipitated. The most striking characteristic of the extraction was the color of the ion pair in the nonether phase. I n adiponitrile for example, CuBr4-2 is dark olive green and C O ( S C N ) ~ -is~ light blue. Since the amine nitrogen is more basic than the ether oxygen, the lack of specificity is not unexpected. Adiponitrile, however, has proven to be a satisfactory solvent for extracting Fe (111) and Mo(V1) from aqueous HCl ( 2 ) and further investigations with it as one of the immiscible, nonaqueous phases may show more significant differences.
E'
LITERATURE CITED
E'
( 1 ) Larson, E. M., Trevorrow, L. E., J . Znorg. A'ucl. Chem. 2,254 (1956).
E
(2) Latimer, G. W., Furman, N. H., Zbid.,
...
... ... ... ...
...
...
... ...
M = phases miscible E = >90% extracted to the non-ether phase P = lo% extracted . . . = Experiment not performed
...
... ... ... 11
24, 729 (1962). (3) Lien, A. P., McCauley, D. A., Everiny, B. L., Ind. Eng. Chem. 41, 2689 (1949). (4) Tsai, K. R., Fu, Y., ANAL.CHEM.21, 818 (1949). (5) Verhoek, F. J., J . Am. Chem. SOC.58, 2577 (1936).
E'
GEORGE W. LATIMER JR.
Pittsburgh Plate Glass, Chemical Division P.O. Box 4026 Corpiis Christi, Texas VOL. 35, NO. 12, NOVEMBER 1963
0
1983
