The method consists in decomposition of the soap by a known volume of standard volumetric mineral acid solution, extraction and separation of the liberated fatty matter with light petroleum and determination of a total alkali content by titration of the excess of acid contained in the aqueous phase with a standard volumetric sodium hydroxide solution. After evaporation of the light petroleum from the extract, dissolution of the residue in ethanol and neutralization of the fatty acids with a standard volumetric potassium hydroxide solution. Evaporation of the ethanol and weighing of the soap formed to determine the total fatty matter content.
ISO 685:1975Stage: 95.99
Got a question?
Check out our FAQs
Monday to Friday - 09:00-12:00, 14:00-17:00 (UTC+1)
Keep up to date with ISO
Sign up to our newsletter for the latest news, views and product information.