Agents de surface — Détermination de l'alcalinité libre ou de l'acidité libre — Méthode titrimétrique

The determination is carried out in the following way: Titration of an ethanolic or propanolic solution of the product with a standard volumetric potassium hydroxide or hydrochloric acid or sulphuric acid solution whichever is appropriate, in the presence of phenolphthalein as indicator.