Sunday, July 3, 2011


       In view of the wide range of products available and the possibility of complex mixtures being marketed it is not possible to devise a general scheme of analysis which will cover all cases. Extraction with a non polar solvent such as petroleum wther will remove solvents unsatisfied fats and oil subsequent extraction with absolute alcohol will remove soaps and oxidized fatty bodies.

The residue will consist of suspected and opinionated bodies together with inorganic alcohol insoluble substances. A simple scheme of this kind must however be regarded as qualitative only. A considerable knowledge of the chemistry of oils and soap is necessary to deal with the more complex cases adn the methods given are merely for routine control of deliveries . Efforts should be directed towards performance tests on a value basis rather than towards chemical analysis in detail.

         Soaps employed in the textile industry are mainly the sodium or potassium salts of oleic palmistry and stearic acid in admixture in the proportions in which they occur naturally in such oils as olive oil and are chis oil. For certain purposes coconut oil soaps are used which are mainly sodium laureate. Soaps have good wetting and detergent power but are unstable chemically being decomposed by acids and precipitated from solution by calcium and magnesium salts in hard water.