Isotopic Method for Direct Determination of Oxygen in Fluorocarbon

Chem. , 1952, 24 (8), pp 1361–1362. DOI: 10.1021/ac60068a029. Publication Date: August 1952. ACS Legacy Archive. Cite this:Anal. Chem. 24, 8, 1361-1...
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V O L U M E 24, NO. 8, A U G U S T 1 9 5 2

1361

chloride had been oxidized. Upon vigorous boiling of the same t!pe of solutions for 10 minutes, 3.5% of the chloride ion was oxidized.

water to 150 ml. Two drops of osmium tetroxide solution a e r e added for catalysis, and the resulting rnisture was back-titrated with 0.1000 S arsenious acid solution. S e a r the end point, 2 drops of ferroin indicator were added.

METHOD FOR DETERMISATIOh O F HYDROXYLAMINE

Tables I1 and I11 give the data which were obtained for the determination of both hydroxylammonium salts, and support the following equation for the reaction:

thorough stud\- of the effect of acidity, volume of solution, boiling. presence of chloride ion, and concentration of oxidant was made in an effort t o design a procedure to be used in a quantitative deterniination of hydroxylamnionium salts.

2SH2OH

+ 4Ce(SO4j,

+

S,O

+ 2C(:.(S04;3 + fI,O + 2H?SO,

LITERATURE CITED

Fift>-milliliter> of 0.1 ATammonium tetrasulfato cerate solution in 1 S sulfuric acid, which had been qtandardized against 0.1000 -T arsenious acid. were pipetted into a 500-ml. Erlenmeyer flask. Fifteen milliliters of 6 -1-sulfuric acid were added. The mixture was brought to boiling, but not removed from the heat. TThile the solution was boiling gently, 25.00 ml. of hydroxylamine eoluhon n-ere added. The contents of the flask were boiled gently tor 1 minutp. removed from the heat. cooled, and diluted with

(1) Henrath, d..and Rulmd, Ii., Z.anorg. u.allgeni. C h m . . 114,2G777 (1920). (2) Eray, W. C., Simpson, .\I. E., and MacKeneie, A . 1.. J. Am. Chem. floc., 41, 1363--~78(1919). (3) XIilligan, L. H., J. r h u s . Chenz., 28, 544 (1924). (4) l'rozsolo, A. M., and Lieher, E., ANAL.CHEM.,22, 766 (1950). RECEIVED for review February 8. 1952. Accepted hpril 20.

15152,

Isotopic Method for Direct Determination of Oxygen in Fluorocarbon Derivatives A.

I). KIRSHENBAURI, A. G. STRENG, AND A. V. GROSSE Research Institute, Temple University, Philudelphiu, Pa.

GOOD direct method was needed for determining the oxygen

-ji content of substituted Huoroearbon derivatives.

The direct methods used for the determination of ovygen in organic compounds are the Schutze-Unterzaucher method ( 1 , 2 , 7 , 11, IS! 14), the ter Meulen method (3, 10, 12, 15), and the elementary isotopic method ( 4 4 ) . Xeither the Gchutze-Unterzaucher method of analysis, based on the thermal deconiposition of the organic compound over carbon, nor the ter Meulen method of analysis, har;ed on the reduction of the organic compound by hydrogen. could be used on fluorocarbon compounds, as they are very stable to thernial decomposition and hydrogenation. The elenientary isotopic method can. hoi ]

lactone was prepared by thermal degradation of silver hexafluoroglutaratewith excess iodine. I t had a melting point of -59'C., a boiling point of +18" C., and a molecular weight (by gas density balance) of 194; the theoretical molecular weight is 194. The lactone upon analysis (carbon analysis by Clark Xficroanalytical Laboratories, Urbana, Ill.) mas found to contain 24.337, carbon; the calculated per cent carbon for C4F& IS 24.76. The sample was titrated with sodium hydroxide and 1.00 mole of lactone reacted with 3.99 moles of sodium hydroxide ( = 3.99 equivalents of acid). A direct determination of the fluoride in the sodium hydroxide solution showed that 1.96 equivalents of hydrogen fluoride were present. The difference of 2.03 equivalents of acids corresponds to 1.015 moles of tetrafluorosuccinic acid (instead of the theoretical 1.00 mole):

CFz-C OOSa

F,C-C=O I

\

!

I

+ 4SaOH +CF,-COOSa + 2 S a F + 2 H 2 0 /

0

FZC-CF,

LITER-4TURE CITED

Aluise, .'1 h.,Alber, H. K., Conway, H. S., Harris, C. C., Jones, W.H., and Smith, W.H., -1s.~~. CHEY.,23, 530-3 (1951). (2) Aluise, V. A., Hall, R. T., Staats. F. C . , and Becker, W.Ti., Ibid., 19, 347-51 (19471. (3) Elving. P. J . , and Ligett, W. B., C'hem. Reus., 34, 129-56 (1944). (4) Grosse, A. V.. Hindin. S.G., and Kirshenbaum, A. D., . I s a L . CHEY.,21,386-90 (1949). ( 5 ) Grosse, A. V.,Hindin, S . G., and Kirshenbaum, A. D., J . -4m. (1)

Chem. Soc., 68, 2119 (1946) (6)

Grosse, A. V., and Kirshenhaum, .I.D., A N ~ LCHEM., . 24,584-

(7)

Harris, C. C., Smith, D. M , , and Mitchell, J . , J r . , Ibid.,

5 (1952). (8) Hauptschein. M., and Grosse, -\, V., f. Sm. Chem. SOC.,73, 2361 (1951).

(9)

Hauptschein, bf.. Stokes. C . 5..and Grosse, 4 . V.. Ihid.,

74, 1974

(1952). (10) (11) (12)

Lindner. J., and Wirth, K., Her.. 70B, 1025-8 ( 1 9 3 i ) . Xlaylott, A. O., and Lewis. J . R., .INAL. CHEM.,22, 1051 (1950). Russell, W.W., and Fulton, .J. W., IND.ESG.CHEX,AN.AI..E D . ,

(13)

Walton, 1%'.W.,McCulloch, F.W., and Smith, IT. H., J . Re-

(14) (15)

Unteraaucher, J., Chemic Ing. Tech., 22, 39-40 (1950). Vntereaucher, J.. and Burger, I