Differences in fatty acid composition of fish faeces as determined by two extraction methods

Abstract

AbstractChloroform‐methanol, a supposedly efficient solvent system for lipid extraction, was applied to heterogeneous samples, respectively fish diets and fish faeces. Comparisons were made of the compositions of the fatty acids prepared from solvent‐recovered lipids with those obtained by total saponification. These show that solvent extraction, followed by saponification prior to fatty acid methyl ester preparation, gives differences attributable to incomplete extraction. Direct sample saponification in ethanolic alkali is recommended if all fatty acids in the diet are of interest.