Reversed phase high performance liquid chromatographic studies for homologous series of polyunsaturated fatty acids on a commercial μBondapak free fatty acid column

Abstract

Reversed phase high performance liquid chromatography (RPHPLC) has been proven to be one of the most efficient and reproducible separation methods for fatty acids since 1974. Particularly, in the case of homologous series studies, RPHPLC is an exclusively unavoidable method. The thermodynamic and kinetic studies for free fatty acids, oleic acid (octadecenoic acid 18:1Δ9c), linoleic acid (octadecadienoic acid, 18:2Δ9c, 12c), linolelaidic acid (octadecadienoic acid, 18:2Δ9t, 12t), linolenic acid (octadecatrienoic acid, 18:3Δ9c, 12c, 15c), γ-linolenic acid (octadecatrienoic acid, 18:3Δ6c, 9c, 12c), eicosadienoic acid (eicosadienoic acid, 20:2Δ11c, 14c) and eicosatrienoic acid (eicosatrienoic acid, 20:3Δ11c, 14c, 17c) were performed on a 10 μ commercial alkyl phenyl free fatty acid column. The mobile phase was acetonitrile, water and tetrahydrofuran in the ratio of 45:35:20 v/v%. The isocratic elution method was adopted in these studies using differential refractometer as detector. The retention data was obtained and thereby capacity factors, enthalpies of adsorption were calculated. Finally the retention mechanism was explained.