IMPROVED SEPARATION OF SOME POSITIONAL ISOMERS OF MONOUNSATURATED FATTY-ACIDS, AS THEIR PHENACYL DERIVATIVES, BY SILVER-ION THIN-LAYER CHROMATOGRAPHY

The separation of two groups of positional isomers of monoenoic fatty acids 6-18:1, 9-18:1 and 11-18:1, and 5-20:1, 8-20:1, 11-20:1, and 13- 20:1, as their phenacyl esters, has been achieved by silver-ion thin l ayer chromatography at ambient temperature on home-made and precoated silica gel plates. The resolution achieved is much better than that re ported previously for the corresponding methyl esters, which confirms that the nature of the fatty acid derivative can affect the separation of fatty acid isomers by silver ion chromatography.