CHARACTERIZATION AND PURIFICATION OF POLYUNSATURATED FATTY-ACIDS FROMMICROALGAE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY AND COUNTERCURRENTCHROMATOGRAPHY

The present study was undertaken in order to characterize then to puri fy fatty acids from marine phytoplankton. From a crude mixture of fatt y acid methyl esters it was possible to isolate by countercurrent chro matography a mixture of four polyunsaturated fatty acid methyl ester i dentified as being hexadecatrienoic acid methyl ester, octadecatetraen oic acid methyl ester, eicosapentaenoic acid methyl ester and docosahe xaenoic acid methyl ester by gas chromatography coupled with mass spec trometry in electron impact and in positive-ion chemical ionization mo de. The four polyunsaturated fatty acids are in different ratios in mi xtures from the two microorganisms: Skeletonema costatum and Isochrysi s galbana.