358 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (20) P. Sherman, "Rheological Changes in Emulsions on Aging,"J. Coll. and Interf Sci., 24, 107-114 (1967). (21) D. E. McVean and A.M. Mattocks, "Simple Rheometer for Definition of Viscoelastic Properties of Structured Liquids,"J. Pharm. Sci., 50, 785-788 (1961). (22) J. H. Wood and G. Catacalos, "Prediction of The Rheological Aging of Cosmetic Lotions,"J. Soc. Cosm. Chem., 14, 147-156 (1963).

j. Soc. Cosmet. Chem., 33, 359-362 (November 1982) Analysis of glycine in antiperspirant products by HPLC DAVID CHIN and RAJA G. ACHARI, Bristol-Meyers Products, 1350 Liberty Avenue, Hillside, NJ 07207. Received May 19, 1982. Synopsis A liquid chromatographic method for the assay of glycine in antiperspirant products is described. The chromatographic separation of glycine is carried out using a Zorbax NH2 column and a mobile phase consisting of 0.01M potassium dihydrogen phosphate in 7:3 (V/V) acetonitrile: water. Glycine is monitored by U.V. at 200 nm. The method has been documented to be precise and accurate and has been successfully applied in assaying commercially available antiperspirant products. INTRODUCTION Mixed aluminum and zirconium salts are potent antiperspirants however, due to their gelling and skin irritating potential, glycine is used as a buffering agent. Glycine also plays a role in fabric protection (1). Glycine is currently analyzed in antiperspirant preparations by a reaction of glycine with cyanide-ninhydrin reagent, and the resulting mixture is assayed colorimetrically (2). The intensity of color is very susceptible to reaction temperature and the amount of reagent added, and even a slight variation in the procedure often leads to irreproducible results. We report here a simple HPLC procedure which requires no derivatization of glycine and can be applicable to most commercially available antiperspirant products. METHODS APPARATUS A modular liquid chromatographic unit consisting of a constant flow solvent delivery pump (Model 6000A, Waters Assoc., Milford, Mass.), a continuously variable Wavelength UV-VIS Spectroflow monitor (Spectro Monitor - III, Laboratory Data Control, Riviera Beach, Fla.), a strip chart recorder (Model 56, Perkin-Elmer Corp., Norwalk Ct.), and a device (Model Vista 401, Varian Associates, Santa Clara, Ca.) to integrate the area under the curves of the eluates, were used for chromatography. A carbohydrate column (Zorbax NH2, 25 cm x 4.6 mm I.D., bp 5-6/• DuPont Co., Wilmington Del.) was used for separation of glycine with a mobile phase consisting of 359