PHYSICAL ASPECTS OF FOAM 311 (12) (13) (14) (15) 06) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) Clark, N. O., and Blackman, M., The transmission of light through foam, Trans. Faraday Soc., 44, 7-13 (1948). Bikeman, J. J., Foams: Theory and Industrial Applications, Reinhold, New York, 1953, p. 144. Chang, R. C., Schoen, H. M., and Grove, C. S., Jr., Bubble size and bubble size deter- mination, Ind. Eng. Chem., 48 (11), 2035-9 (1956). Kitchener, J. A., Foams and Free Liquid Films, in Danielli, J. F., Pankhurst, K. G. A., and Riddiford, A. C., Recent Progress in SurJace Science, Vol. 1, Academic Press, New York, 1964, pp. 68-71. Vrij, A., Possible mechanism for the spontaneous rupture of thin free liquid films, Discuss. Faraday Soc., 42, 23-33 (1966). Vrij, A., and Overbeek, J. Th. G., J. Amer. Chem. Soc., 90, 3074-8 (1968). Culick, F. E. C., Comments on a ruptured soap film, J. Appl. Phys., 31, 1128-9 (1960). Frankel, S., and Mysels, K. J., The bursting of soap films. II. Theoretical considera- ti,ons, J. Phys. Chem., 73, 3028-38 (1969). deVries, A. J., Morphology, Coalescence, and Size Distribution o[ Foam Bubbles, in Lemlich, R., Adsorptiv½ Bubble Separation Techniques, Academic Press, New York, 1972, pp. 7-31. Princen, H. M., Overbeek, J. Th. G., and Mason, S. G., The permeability of soap films to gases. II. A simple mechanism of monolayer permeability, J. Colloid InterJace Sci., 24, 125-30 (1967). Ross, S., Bubbles and foam, Ind. Eng. Chem., 61 (10), 48-57 (1969). Lemlich, R., Principles o[ Foam Fractionation and Drainage, in Lemlich, R., Adsorp- tive Bubble Separation Techniques, Academic Press, New York, 1972, pp. 33-51. Shih, F. S., and Lemlich, R., A study of interstitial liquid flow in foam. Part III. Test of theory, AIChE J., 13, 75l-4 (1967). Lavi, E., and Lemlich, R., Foam fractionation with reflux, Science, 134, 191 (1961). Lemlich, R., Principles o[ Foam Fractionation, in Perry, E. S., Progress in Separation and Purification, Vol. 1, Interscience (Wiley), New York, 1968, pp. 1-56. Rubin, E., and Gaden, E. L., Jr., Foam Separation, in Schoen, H. M., New ChemiCal Engineering Separation Techniques, Interscience (Wiley), New York, pp. 319-85. Lemlich, R., Adsorptive bubble separation methods, Ind. Eng. Chem., 60 (10), 16-29 (1968).* Lemlich, R., Separations Based on Bubble Adsorption, in Perry, R. H., and Chilton, C. H., Chemical Engineerrs Handbook, 5th ed., McGraw-Hill, New York, in press. Lemlich, R., Foam fractionation, Chem. Eng., 75 (27), 95-102 (1968)*. Errata in 76 (6), 5 (1969). Lemlich, R., Adsubble Methods, in Li, N. N., Recent Developments in Separation Sci- ence, Chemical Rubber, Cleveland, Ohio, in press. Lemlich, R., Adsubble methods, Chem. Eng., 73 (21), 7 (1966). Karger, B. L., Grieves, R. B., Lemlich, R., Rubin, A. J., and Sebba, F., Nomenclature recommendations for adsorptive bubble separation methods, Separ. Sci., 2, 401-4 (1967). Lemlich, R., ed., Adsorptive Bubble Separation Techniques, Academic Press, New York, 1972. * The interested reader is referred to p. 36 of ref. 23 for clarification of an ambiguity in refs. 28 and 30 regarding the quantitative effect of collector micelies.

]. Soc. Cosmet. Chem., 23, 313-319 (May 23, 1972• Gas-Liquid Chromatographic Determination ot Castor Oil as Methyl Ricinoleate in Lipstick GEORDIE L. PAULUS, B.S.,* and MARGAREE H. CHAMPION, B.S.* Presented October 11, 1971, Joint Symposium of the Association of Ol•- cial Analytical Chemists-Society of Cosmetic Chemists, Washington, D.C. Synopsis--CASTOR OIL, which consists chiefly of the triglycerides of ricJnoleic acid, can be determined in a LIPSTICK as a function of Rs ricinoleic acid contenet. The ricingoleic acid glyceride is converted into its methyl ester by transesterification. The ester, isolated by ex- traction, is determined by GAS-LIQUID CHROMATOGRAPHY. The glc column used for the analysis of methyl ricinoleate is packed with 4% Carbowax 20M-terephthalic acid on Gas Chrom RZ. INTRODUCTION It has been reported that the ricinoleic acid glyceride content of naturally occurring castor oil varies from 82 to 87% (1-$). Gas-liquid chromatographic (glc) analyses conducted in our laboratories indicate that the ricinoleic acid glyceride content is 90%. The glc procedure developed in our laboratory for the determina- tion of glycerides of ricinoleic acid present in caster oil requires the transesterification of the ricinoleic acid glyceride contained in the lip- * Present address: Warner-Lambert Pharmaceutical Co., 170 Tabor Rd., Morris Plains, N. J. 07950. t Division of Colors and Cosmetics Technology, Food and Drug Administration, U.S. Department of Health, Education, and Welfare, Washington, D.C. 20204. 313