A reverse phase high-pressure liquid chromatographic technique for the analysis of some common saturated and unsaturated fatty acids as their p-phenylphenacyl esters

Abstract

A technique for the analysis of some common natural fatty acids has been developed by the use of reverse-phase high performance liquid chromatography (RPLC) . The fatty acid standards were derivatised with 1?_-phenylphenacyl bromide via the potassium salt or using tetra--n-butylammonium hydrogensulphate as phase-transfer catalyst. The £-phenylphenacyl esters of dodecanoic (c12 :0), tetradecanoic (c14 :0), hexadecanoic (c16 :0), Z-9-hexadecenoic (c 16 : l;gz), octadecanoic (ClB :O)' Z-9-octadecenoic (ClB :l; 9Z), E-9-octadecenoic (ClS : l; 9E), Z-9, Z-12-octadecadienoj _ (c18 :2; 9Z,l 22), Z-9, Z-12, Z-15-octadecatrienoic (ClB :J;gz,l 2Z,lSZ), 12-hydroxy-Z-9-octadecenoic (ClB:l ; 9Z(l20H)) and Z-13-docosenoic (c22 :l;lJZ) acids were synt tesized and characterized . The last five esters have not been synthesized previously.

These fatty acid es er derivatives were then chromatographed on a 5u ult r a phere ODS column using various mobile phases , including absolute methanol, methanol-water, methanol-acetonit rile and methanol-acetonitrile-water m·xtures. The best mobile phase was found to be a mixture of methanol , acetonitrile and water , which made it possible to resolve all of the critical pairs (£-phenylphenacyl ester derivatives of hexadecanoic (c16 :0) & Z- 9- octadecenoic......