Abstract <p>Results are summarized from liquid chromatography of a complex mixture of unsaturated lipid molecules as the basis of a hydrophobic matrix of biomembranes. Data on the relative retention of such lipids, including residues of the most important fatty acids, allow calculations of the most characteristic general parameters that satisfactorily determine their behavior when a silver salt is introduced into a planar or column liquid chromatographic system in order to sharply increase the selectivity of separating unsaturated lipid molecules. A variant is proposed of quantitatively assessing the relationship between the selectivity of separating individual molecules of natural lipids with the proposed parameters of fatty acid residues included in their composition, which are calculated on the basis of variations in the chemical potential of such molecules when silver appears in this system.</p>