Skip to main content
SpringerLink
Log in

Rapid determination of free fatty acids in vegetable oils by gas liquid chromatography

  • Technical
  • Published:
Journal of the American Oil Chemists’ Society

Abstract

Determination of the free fatty acids in small quantities of vegetable oil is accomplished by gas liquid chromatography. The free fatty acids are isolated from a hexane solution of the vegetable oil into an aqueous solution of trimethylphenylammonium hydroxide (TMPH). Due to the alkalinity of TMPH, the free fatty acids readily partition into this aqueous phase. Injection of the free fatty acid-TMPH salts into a gas chromatograph results in pyrolytic methylation of the free fatty acid salts—yielding the methyl esters. Excellent results were obtained when this new procedure was used on neutral lipid oils containing known amounts of free fatty acids and compared with the results obtained by a modified BF3/MeOH esterification procedure. When compared to the AOCS titration procedure, this new procedure gave comparable results. This new procedure has advantages over the AOCS procedure: it is more sensitive and gives quantitative results for individual free fatty acids. This new procedure also has several advantages over the modified BF3/MeOH esterification procedure: it is easily and more rapidly performed, there is no deposition of glyceride on the column when the sample is injected, and because there is quantitative recovery, the new procedure is more sensitive and can be used on oils with a low weight percentage of free fatty acids.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Official and Tentative Methods of the American Oil Chemists' Society, 3rd edn., Vol. 1 and 2, AOCS, Champaign, IL, 1964 (revised to 1972), Method Ca5a-40.

  2. Ottenstein, D.M., and W.R. Supina, J. Chromatogr. 91:119 (1974).

    Article  CAS  Google Scholar 

  3. Chapman, G.W., Jr., JAOCS, 56:77 (1979).

    CAS  Google Scholar 

  4. D'Alonzo, R.P., W.J. Kozarek, and H.W. Wharton, JAOCS 58:215 (1981).

    Article  Google Scholar 

  5. MacGee, J., and K.G. Allen, J. Chromatogr. 100:35 (1974).

    Article  CAS  Google Scholar 

  6. Williams, M.G., and J. MacGee, Ibid. 234:468 (1982).

    Article  CAS  Google Scholar 

Download references

Author information

Author notes

  1. M. G. Williams

    Present address: Cancer Research, The Upjohn Company, 49001, Kalamazoo, MI

Authors and Affiliations

  1. Basic Science Laboratory, Veterans Administration Medical Center, 3200 Vine Street, 45220, Cincinnati, OH

    M. G. Williams & J. Macgee

  2. Departments of Internal Medicine and Biological Chemistry, College of Medicine, University of Cincinnati, 45267, Cincinnati, OH

    M. G. Williams & J. Macgee

Authors
  1. M. G. Williams
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. J. Macgee
    View author publications

    You can also search for this author in PubMed Google Scholar

About this article

Cite this article

Williams, M.G., Macgee, J. Rapid determination of free fatty acids in vegetable oils by gas liquid chromatography. J Am Oil Chem Soc 60, 1507–1509 (1983). https://doi.org/10.1007/BF02666572

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02666572

Keywords

Search

Navigation