Abstract / scope
Describes a method based on the Schmid-Bondzynski-Ratzlaff principle which consists in digesting a test portion with hydrochloric acid, adding ethanol and subsequently extracting the acid-ethanolic solution with diethyl ether and light petroleum, removing the solvent by distillation or evaporation, and determining the mass of the substances extracted which are soluble in light petroleum. The annex includes the description of an alternative procedure using fat-extraction tubes with siphon or washbottle fittings.