| Abstract: | To determine the content of individual fatty acids of fish by gas-liquid chromatography, samples are normally extracted with suitable solvents and the crude lipid extract obtained thereby is derivatized to form fatty acid methyl esters in a subsequent reaction. Alternatively, freeze-dried fatty fish is reacted with toluene/methanolic-HCI for simultaneous extraction and methylation of lipids contained in the testing material. Sample preparation by this one-step method is not only much easier but also as efficient as lipid extraction with chloroform/methanol and derivative formation by base-catalyzed methanolysis of lipids. Both approaches resulted in comparable figures for the content of individual fatty acids per g dry matter even for the highly unsaturated fatty acids typical for fish lipids. |
