Chromatographic investigation of the hydrophobic properties of selected cis-trans geometrical isomers

Summary Selected cis-trans isomers were semiquantitatively compared in respect to their hydrophobic properties. Investigations were carried out by thin-layer adsorption and partition chromatography; the solubilities of the individual substances in water were also determined. The results were evaluated to explain the comparatively weaker hydrophobic properties of the cis-isomers as compared to their trans-counterparts.     

Chromatographic separation of tocopherols.

alpha-, beta-, gamma-, and delta-Tocopherols were separated by reversed-phase high-performance thin-layer chromatography (C18RP-HPTLC), normal-phase high-performance liquid chromatography (NP-HPLC), reversed-phase high-performance liquid chromatography (C18RP-HPLC), and gas chromatography (GC). The selected topological indices based on connectivity (M, 1chi(v)), on distance matrix (W, (o)B, MTI) and on information theory (I(AC), I(AC)) were calculated for these tocopherols. The observed chromatographic separations of investigated tocopherols were compared. This comparison indicated that the C18RP-HPTLC, NP-HPLC, and GC are the best techniques for the separation of these tocopherols. Topological index (o)B was the most significant. We obtained definite dependence between the numerical values of topological index (o)B and the chromatographic separation of the investigated tocopherols.