Abstract
The methyl eicosenoate, docosenoate, octadecatetraenoate, eicosapentaenoate and docosahexaenoate were isolated from the fatty acid methyl ester of skipper oil by urea fractionation, followed by vacuum fractional distillation.
The process of the fractionations and the purity of each individual ester were checked by gasliquid chromatography.
The structures of these acids were determined by oxidative ozonolysis with identification of the fragments (as benzyl and or methyl esters) by gas-liquid chromatographic analysis.
These five acids were identified as :
Δ9 eicosenoic acid
Δ11 docosenoic acid
Δ6, 9, 12, 15 octadecatetraenoic acid
Δ5, 8, 11, 14, 17 eicosapentaenoic acid
Δ4, 7, 10, 13, 16, 19 docosahexaenoic acid
The procedure, benzyl-esterification followed by gas-liquid chromatography, may be available for semi-quantitative analysis of low molecular monobasic acids in water, for its simple process and fairly high yield (8090%).
