Journal of the American Oil Chemists Society

, Volume 45, Issue 3, pp 169–171 | Cite as

An automated method for determining free alkalinity or acidity in soap

  • W. E. Hoover
  • M. E. Ginn
  • Eric Jungermann
Technical Symposium: Lipid Monolayer And Bilayer Models And Cellular Membranes. Part I.


An AutoAnalyzer method has been developed to determine free alkalinity or acidity in soap by use of a mixed cresol red-phenolphthalein indicator solution and by measurement of the color developed at 550 mµ. An internal standard or reference solution is used consisting of a soap solution which has been adjusted to represent neutrality. The method was applied for 0 to 0.10% free alkalinity, calculated as sodium hydroxide, and for 0 to 0.50% free acidity calculated as oleic acid. Attainable precision of the method (95% confidence limits) in the ranges explored was found to be ±0.0025% for free alkali and ±0.05% for free acidity.


Reference Solution Phenolphthalein Barium Chloride AOCS Official Free Alkali 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Hoover, W. E., M. E. Ginn and E. Jungermann, JAOCS44, 175–177 (1967).CrossRefGoogle Scholar
  2. 2.
    Cox, H. E., et al., Analyst62, 30–41 (1937).CrossRefGoogle Scholar
  3. 3.
    Accinelli, A., Olii minerali, grassi e saponi, colori e vernici29, 17–22 (1952); C. A.47, 2517 b (1953).Google Scholar
  4. 4.
    Biffen, F. A., Oil and Soap18, 14 (1941).CrossRefGoogle Scholar
  5. 5.
    Uhlig, H. H., and F. C. Duemmling, Oil and Soap13, 307–314 (1936).CrossRefGoogle Scholar

Copyright information

© American Oil Chemists 1968

Authors and Affiliations

  • W. E. Hoover
    • 1
  • M. E. Ginn
    • 1
  • Eric Jungermann
    • 1
  1. 1.Household Products Research and Development DepartmentArmour Grocery Products CompanyChicago

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