Validation of a gas–liquid chromatographic method for analysing samples rich in long chain n−3 polyunsaturated fatty acids: Application to seafood

Seafood, in general, contains high levels of long chain n−3 polyunsaturated fatty acids (LC n−3 PUFAs), and its consumption has been shown to have positive effects on human health. A method previously reported to be highly effective for PUFA analysis in beef, based on saponification, double extraction and methylation by trimethylsilyl-diazomethane, was validated for seafood fatty acid (FA) determination. The method could be highly suitable for FA analysis in marine tissues since it has shown higher effectiveness in PUFA analysis than classic methods, avoids the production of base-catalyzed artifacts and removes non-saponifiable lipids from the sample. The method was evaluated on three seafood matrices: molluscs (Chamelea gallina), crustaceans (Parapenaeus longirostris) and fish (Pagellus bogaraveo), and 10 FAs representative of seafood were used. Overall recovery values from the three matrices ranged from 80% to 107%. Intra-day RSD ranged between 0.5% and 7.2%, with an average value of 3.4%, while inter-day RSD values ranged between 1.1% and 9.7%, with an average value of 5.7%. Consistent recovery and RSD values were obtained and the method was deemed to produce acceptable accuracy. The applicability of the method to the determination of total FAs in samples rich in LC n−3 PUFA, as seafood products, was demonstrated.