Soap-Making Manual / A Practical Handbook on the Raw Materials, Their Manipulation, Analysis and Control in the Modern Soap Plant.

by Edgar George Thomssen

UNSAPONIFIED MATTER.

Dissolve 5 grams of soap in 50 cubic centimeters of 50 per cent. alcohol. Should any free fatty acids be present neutralize them with standard alkali. Wash into a separatory funnel with 50 per cent. alcohol and extract with 100 cubic centimeters of gasoline, boiling at 50 degrees to 60 degrees C. Wash the gasoline with water, draw off the watery layer. Run the gasoline into a weighed dish, evaporate the alcohol, dry and weigh the residue as unsaponified matter. The residue contains any hydrocarbon oils or fats not converted into soap.