Experimental Ebullioscopic Constants - Analytical Chemistry (ACS

Relation between volatility rating and composition of phenoxy herbicide ester formulations. Alan Noble , Denis J. Hamilton. Pesticide Science 1990 28 ...
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V O L U M E 25, NO. 9, S E P T E M B E R 1 9 5 3 Table IV. Determination of Cyclohexanol and Cyclohexanone in Cyclohexane" Cyclohexanol Cyclohexanone Added, P.P.M. Found, P.P..M. Added, P.P.M. Found, P.P.M. 1.0 1.6 4.2 3.8 2.3 2.5 3 3 3.5 3 5 2.1 1 5 3.8 4 6 4 3 14 1 3 a One milliliter of cyclohexane aolution mas taken as sample -

_____ _ ~ _ _ ~. . Analysis for Isovaleraldehyde in Succinic kcid ~

Table V.

Absorbancy at 550 nip 0.095 0.243 0.328 0.653 0.785

Isovaleraldehydr. 3Iole '7c Added Found 0.011

0.012

0.033 0.044

0.034 0.046 0.093 0.I14

0.088

0.110

1379 of relatively large quantities of pure succinic acid. Some results from this application are presented in Table V. Concentrations of 0.01 to 0.1 mole % of aldehyde in the acid were determined with good accuracy. In all cases 100-mg. samples of the succinic acid were taken. These results were obtained after reference to a calibration curve obtained with pure isovaleraldehyde. CONCLUSIONS

Although the Komaron-sky reaction is not highly specific. it provides a rapid and reasonably precise means of analysis for those cases in which it can be applied. Generally, these comprise simple binary systems in which the major component does not react. More complicated mixtures may be analyzed if the absorption maxima of the components are sufficiently separated as was shoirn for mixtures of cyclohexanol and cyclohexanone in cyclohexane. ACKNOWLEDGMENT

The data in Table IC indicate that cyclohexanol can be measured with greater accuracy than cyclohexanone, because of the correction for cyclohexanol incorporated into the calculation for cyclohexanone. The interesting observation was made that the cvclohexanol color disappeared on dilution with water, whereas the cyclohexanone color persisted. This could be incorporated into the analytical procedure with resulting simplification of the calculations. Determination of Isovaleraldehyde in Succinic Acid. The Komarowsky reaction may be used for the measurement of small amounts of various aldehydes in the presence of organic acids which do not give a positive color test. The present analytical procedure was used to determine isovaleraldehyde in the presence

The authors wish to acknowledge the valuable assistance of Ella Mae Gardner and Anne Greco in obtaining many of the data reported in this paper. LITERATURE CITED

(1) Coles, H. W., and Tournay, W. E., IND.ENG.CHEM.,ANAL.ED., 14,20-2 (1942). (2) Dal Kogare, S., Korris, T. O., and Mitchell, J., Jr., ANAL.CHEZI., 23. 1473-8 119513. (3) Dal kogare, S:, and Oemler, A. N., Ibid., 24, 902 (1952). (4) Duke, F. R., Ibid., 19,661-2 (1947). (5) Fellenberg, T. von, Mitt.Gebiete Lebensm. u. Hyg., 1, 311 (1910). (6) Komarowsky, A., Chem.-Ztg., 27,807, 1086 (1903). (7) Penniman, W. B. D.. Smith, D. C., and Lawshe, E. I., IND.ESG. CHEM.,AKAL.ED.,9,91-5 (1937). RECEIVED for review January 9, 1953. Accepted .June 18, 1953.

Experimental Ebullioscopic Constants Variation with Molecular Weight of Solztte and Type of Solvent GLIDE i. GLOVER AND CIIkRLO'I'TE: P . HILL Research Laboratories, Tennessee Eastnian Co.. Kingsport, Tenn.

Recently, techniques for measuring small temperature differences in ebullioscopy have been greatly improved. As a result, ebullioscopic molecular weight determinations have been refined to an extent which justifies a critical consideration of the ebullioscopic constant, &. The constant was measured in several of the more common solvents for molecular weight determination with a group of randomly selected solutes ranging in molecular weight from 110 to 891. Only in the case of relatively polar solvents was I