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J. Soc. Cosmet. Chem. 22 421-437 (1971) ¸ 1971 Society of Cosmetic Chemists of Great Britain The water absorption lanolin properties of E. W. CLARK* Presented on 6th October 1970 in London at the Symposium on "New developments in lanolin and its derivatives", organised by the Society of Cosmetic Chemists and the Society of Cosmetic Chemists of Great Britain. Syn0psi•WATEI• ABSORPTION is affected by variations in (a) test method and temper- ature, (b) free alcohol content, and (c) presence of soap or detergent. A new METHOD for determining concentrations 0.04 •o of five NONIONIC DETERGENTS of the ethoxylated alkylphenol or ethoxylated linear alcohol type in LANOLIN or centrifuged wool grease is described:- detergent is extracted into 70 •o v/v isopropanol from a solution of the sample in octane, precipitated with molybdophosphoric acid, degreased with diethyl ether, oxidized with perchloric acid, reduced with metol/sulphite to molybdenum blue and the colour intensity measured on a photoelectric colorimeter using a red filter with reference to an individual or composite calibration graph. Accuracy is _ 0.03 as •o sample (detergent known) or --0.06 to +0.05 •o (detergent unknown). Stated detergents are recoverable sufficiently pure for identification by infra-red spectra and their bulk removal from lanolin and wool grease by extraction with 45 •o isopropanol is demonstrated. An addendum names two further amenable detergents. INTRODUCTION One of the most important properties of anhydrous lanolin, its powerful w/o emulsifying action, was utilized in Otto Braun's original patented process (1, 2) for refining crude wool grease to lanolin by repeated kneading with cold water to remove water-soluble impurities. Most national pharmacopoeia include a monograph not only on anhy- drous lanolin but also on the hydrous version, a w/o emulsion. Sometimes *Westbrook Lanolin Company, Laisterdyke, Bradford, BD4 8AU. 421