This International Standard specifies a method for the determination, in detergents, of anionic-active matter hydrolyzable under alkaline conditions. This active matter includes dialkylsulphosuccinates and fatty acid glyceride sulphates. The method is applicable to the analysis of mixtures containing hydrolyzable and non-hydrolyzable anionic-active matter. The molar mass of the two types of active matter must be known or previously determined, if their content is expressed as a percentage by mass.