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Separation of isomeric octadecenoic fatty acids in partially hydrogenated vegetable oils as p-methoxyphenacyl esters using a single-column silver ion high-performance liquid chromatography (Ag-HPLC)

Nature Protocols volume 5, pages 473–478 (2010)Cite this article

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Abstract

A protocol for separation of positionally isomeric trans- and cis-octadecenoic fatty acids as their p-methoxyphenacyl esters, using a single column silver ion high-performance liquid chromatography (Ag-HPLC) with UV detection, is described. The procedure involves hydrolysis of oil to free fatty acids, derivatization to p-methoxyphenacyl esters, purification and separation by Ag-HPLC. The procedure is robust and relatively rapid. In total, it takes about 16 h or overnight and a further 5 h to carry out. Its feature and value consist in the application of p-methoxyphenacyl esters in Ag-HPLC, thus ensuring excellent simultaneous separation of both configurational and positional fatty acid isomers on a single column by a single run. Quantification is not affected by the fatty acid structure, and the method is highly sensitive. As fatty acid isomerization is a strong evidence for adulteration of lipid-containing food products with chemically modified oils and fats, the procedure is especially appropriate for detection and authenticity analysis in many areas of food manufacturing and quality control.

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Figure 1: Preparation of esters.
Figure 2: Ag-HPLC separation.
Figure 3: TLC to check the hydrolysis products.

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Acknowledgements

The partial financial support of the National Science Fund of Bulgaria, project no. X-1513, is gratefully acknowledged.

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Authors and Affiliations

  1. Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria

    Svetlana M Momchilova & Boryana M Nikolova-Damyanova

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  1. Svetlana M Momchilova
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  2. Boryana M Nikolova-Damyanova
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Contributions

S.M.M. contributed to protocol design, performed the analysis and helped to prepare the manuscript. B.M.N.-D. contributed to the basic theoretical assumption, preliminary experiments and protocol design and helped to prepare the manuscript.

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Correspondence to Boryana M Nikolova-Damyanova.

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Momchilova, S., Nikolova-Damyanova, B. Separation of isomeric octadecenoic fatty acids in partially hydrogenated vegetable oils as p-methoxyphenacyl esters using a single-column silver ion high-performance liquid chromatography (Ag-HPLC). Nat Protoc 5, 473–478 (2010). https://doi.org/10.1038/nprot.2009.232

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