Determination of hexane residues in vegetable oils with FTIR spectroscopy

Article

Abstract

The FTIR spectroscopy method was developed for the determination of hexane residues in palm and groundnut (peanut) oils. The method was based on horizontal attenuated total reflectance with a ZnSe crystal at 45° at room temperature, and partial least squares (PLS) statistics were used to derive calibration models. The accuracy of the method was comparable to that of the AOCS Method Ca 3b-87, with coefficients of determination (R2) of 0.9866 and 0.9810 for palm and groundnut oils, respectively, and SE of calibration of 3.83 and 4.91, respectively. The calibration models were validated, and the R2 of validation and the SE of prediction computed. The SD of the difference for repeatability for the method was comparable to that for the standard AOCS method when used for palm and groundnut oils. With its speed and ease of data manipulation by computer software, FTIR spectroscopy has an advantage over present chemical methods, which require preparation of the oil using toxic solvents before GC.

Key words

ATR FTIR spectroscopy hexane residue PLS 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Wan, P.J., Hydrocarbon Solvents, in Technology and Solvents for Extracting Oilseeds and Nonpetroleum Oils, edited by P.J. Wan and P.J. Wakelyn, AOCS Press, Champaign, 1997, pp. 170–185.Google Scholar
  2. 2.
    Wan, P.J., and R.J. Horn, Extraction Solvents for Oilseeds, inform 9:707–709 (1998).Google Scholar
  3. 3.
    Wakelyn, P.J., Regulatory Consideration for Extraction Solvents for Oilseeds and Other Nonpetroleum Oils, in Technology and Solvents for Extracting Oilseeds and Nonpetroleum Oils, edited by P.J. Wan and P.J. Wakelyn, AOCS Press, Champaign, 1997, pp. 48–74.Google Scholar
  4. 4.
    Wan, P.J., and P.J. Wakelyn, Regulatory Considerations of VOC, HAP, inform 9:1155–1160 (1998).Google Scholar
  5. 5.
    U.S. Environmental Protection Agency, EPA Received Data on Commercial Hexane, inform 4:900 (1993).Google Scholar
  6. 6.
    U.S. Environmental Protection Agency, Addition of Certain Chemical Release Reporting; Community Right-to-Know, 56 Federal Register 61439 (1994).Google Scholar
  7. 7.
    Galvin, J.B., Toxicity Data for Commercial Hexane and Hexane Isomers, Ibid., Federal Register 61439, p. 75; cited in P.J. Wan and P.J. Wakelyn, Regulatory Considerations of VOC, HAP, inform 9:1155–1160 (1998).Google Scholar
  8. 8.
    Kemper, T.G., Solvent Recovery and Loss Management, in Technology and Solvents for Extracting Oilseeds and Nonpetroleum Oils, edited by P.J. Wan and P.J. Wakelyn, AOCS Press, Champaign, 1997, pp. 148–152.Google Scholar
  9. 9.
    Standard Methods for the analysis of Oils, Fats and Derivatives, 7th edn., International Union of Pure and Applied Chemistry (IUPAC), Blackwell Scientific Publications, 1987, IUPAC Method 2,607.Google Scholar
  10. 10.
    AOCS, Official Methods and Recommended Practices of the American Oil Chemists' Society, 4th edn., edited by D. Firestone, AOCS Press, Champaign, 1995.Google Scholar
  11. 11.
    Steiner, J., Efforts to Eliminate Toxic Solvents, inform 4:955 (1993).Google Scholar
  12. 12.
    van de Voort, F.R., Fourier Transform Infrared Spectroscopy Applied to Food Analysis, Food Res. Int. 25:397–403 (1992).CrossRefGoogle Scholar
  13. 13.
    van de Voort, F.R., FTIR Spectroscopy in Edible Oil Analysis, inform 5:1038–1042 (1994).Google Scholar
  14. 14.
    Mirghani, M.E.S., Y.B. Che Man, S. Jinap, B.S. Baharin, and J. Bakai, FTIR Spectroscopic Determination of Soap Residues in Refined Vegetable Oils, J. Am. Oil Chem. 79:111–116 (2002).Google Scholar
  15. 15.
    Nzai, J.M., and A. Proctor, Determination of Phospholipids in Vegetable Oil by Fourier Transform Infrared Spectroscopy, Ibid. 75:1281–1289 (1998).Google Scholar
  16. 16.
    Cast, J., Infrared Spectroscopy of Lipids, in Developments in Oils and Fats, edited by R.J. Hamilton, Blackie Academic and Professional, London, 1995, pp. 224–266.Google Scholar
  17. 17.
    George, W.O., and H.A. Willis, Computer Methods in UV, Visible and IR Spectroscopy, The Royal Society of Chemistry, Cambridge, United Kingdom, 1990, pp. 185–190.Google Scholar
  18. 18.
    Fuller, M.P., G.L. Ritter, and C.S. Drapper, Partial Least-squares Quantitative Analysis of Infrared Spectroscopic Data. Part I: Algorithm Implementation, Appl. Spectrosc. 42:217–227 (1988).CrossRefGoogle Scholar
  19. 19.
    Che Man, Y.B., and G. Setiowaty, Multivariate Calibration of Fourier Transform Infrared Spectra in Determining Iodine Value of Palm Oil Products, Food Chem. 67:193–198 (1999).CrossRefGoogle Scholar
  20. 20.
    Nakanishi, K., and P.H. Solomon, Infrared Absorption Spectroscopy, 2nd edn., Holden-Day, San Francisco, 1977, pp. 6, 14–16, 152.Google Scholar
  21. 21.
    Fuller, M.P., G.L. Ritter, and C.S. Drapper, Partial Least-squares Quantitative Analysis of Infrared Spectroscopic Data. Part II: Application to Detergent Analysis, Appl. Spectrosc. 42:228–236 (1988).CrossRefGoogle Scholar
  22. 22.
    Clark, D.H., H.F. Mayland, and R.C. Lamb, Mineral Analysis of Forages with Near Infrared Reflectance Spectroscopy, J. Agron. 97:485–490 (1987).CrossRefGoogle Scholar

Copyright information

© AOCS Press 2003

Authors and Affiliations

  1. 1.Department of Food Technology, Faculty of Food Science and BiotechnologyUniversiti Putra MalaysiaSerdang, Selangor DEMalaysia

Personalised recommendations