COUNTERCURRENT CHROMATOGRAPHIC-SEPARATION OF POLYUNSATURATED FATTY-ACIDS

Hexadecatrienoic acid (C16:3), octadecatetraenoic acid (C18:4), eicosapentaenoic acid (C20:5) and docosahexaenoic acid (C22:6) were purified in two steps by counter-current chromatography (CCC). The selected liquid phases were heptane-acetonitrile-water for the first step and heptane-methanol-water for the second. The upper non-polar phase was kept stationary in the coil of the instrument by a rotational force field. The separation was followed by UV detection at 210 nm and by analysing the eluted fractions by gas chromatography after esterification. The purity of the fatty acids therefore purified was checked by capillary gas chromatography. CCC may be an alternative to HPLC for the preparative-scale purification of such compounds.