Utilization of MS Excel for processing of vegetable oils chromatograms
Abstract
A method for the determination of the species composition of triacylglycerines (TAG) and fatty acid
composition of vegetable oils was proposed using an incremental approach with simple and accessible computer technologies, specifically, a standard MS Excel worksheet. The qualitative determination is based on the additivity of the contributions of functional groups (fatty acid radicals) into the total retention of TAG and their independence from the structure of the other two radicals in the studied TAG pair. To implement the incremental approach, a method was proposed to specify the TAG retention time beyond the linearity of the sorption isotherm. In this case, the best way to determine the retention time is to find the position of the vertical line dividing the peak width into two equal parts. In this work, we used a method for the determination of the “dead” time by retention of series of pseudo-homologues, i.e. TAG groups, with successive replacement of the radicals of one acid for the radicals of another acid. For example, this was implemented with peach oil for the retention times of TAG: L3 – L2O – LO2 – O3 according to the previously proposed scheme based on the recurrent relations of I. G. Zenkevich. Following the analysis of the peach oil chromatograms, key increments were calculated for sequential replacement of linoleic-oleic-palmitic-stearic acids. These increments were used for the calculation of the composition of TAG of Nigella damascena seed oil. Quantitative determination of the shares of TAG types required the use of correction factors for experimental values of peak areas due to the dependence of the refractometric detector sensitivity on the difference in refraction coefficients between the mobile phase (experimental data) and the refraction coefficients of individual TAGs calculated in ChemSketch 12.0. The procedure for the arrangement of a worksheet with the indication of the formulas used for calculations is described. The method was used to determine the TAG and fatty acid composition of Nigella damascene L.
seed oil. As a result, it was found that the oil contains a unique digomolinoleic acid (C22:211Z14Z).
Downloads
References
Deineka V.I., Russ. J. Phys. Chem. A, 2008, Vol. 82, pp. 108-111. https://doi.org/10.1134/S0036024408010160
Deineka V.I., Staroverov V.M., Fofanov G.M. et al., Pharm. Chem, J., 2002, Vol. 36, pp. 392-395. https://doi.org/10.1023/A:1024813914213
Herslöf B.F., Podlaha O. et al. J. Am. Oil Chem. Soc., 1979, Vol. 56, pp. 864-866. https://doi.org/10.1007/BF02909537.
Podlaha O., Töregard B. J. High Resol. Chromat., 1982, Vol. 5, pp. 553-558.
https://doi.org/10.1002/jhrc.1240051007.
Sempore J.B.G., J. Chromat., 1986, Vol. 366, pp. 261-282. DOI: 10.1016/s0021-9673(01)93474-0.
Lin J., Snyder L.R., Mckeon T.A., J. Chromat. A, 1998, Vol. 808, pp. 43-49.
https://doi.org/10.1016/S0021-9673(98)00134-4.
Takahashi K., Zama K., J. Am. Oil Chem. Soc., 1985, Vol. 62, pp. 1489-1492. https://doi.org/10.1007/BF02541900.
Deineka V.I., Burzhinskaya T.G., Deineka L.A. Analytics and control, 2019, Vol. 23, pp 501-508. [in Russ.].
Deineka V.I., Deineka L.A., Gabruk N.G. et al. J. Anal. Chem., 2003, Vol. 58, pp 1160-1165.
https://doi.org/10.1023/B:JANC.0000008956.07835.51.
Daukšas E., Venskutonis P.R., Sivik B., J. Food Sci. 2002. Vol. 67, pp. 1021-1024.
https://doi.org/10.1111/j.1365-2621.2002.tb09447.x
Telci I., Sahin-Yaglioglu A., Eser F. et al. J. Am. Oil Chem. Soc., 2014, Vol. 91, pp. 1723-1729. DOI: 10.1007/s11746-014-2513-3
Parhizkar S., A Latiff L., Abd Rahman S., Scientific Research and Essays, 2011, Vol. 6, pp.
-6820. DOI: 10.5897/SRE11.469. DOI: 10.5897/SRE11.469
Khoddami A., Ghazali H.M., Yassoralipour A. et al., J. Am. Oil Chem. Soc., 2011, Vol. 88,
pp. 533-540. https://doi.org/10.1007/s11746-010-1687-6
