Optimization of gas chromatography method for analysis of fatty acid compositions in different lipid sources using flame ionization detector and mass spectrometry detector.

Abstract

Fatty acids (FAs) serve as an important source of energy and have important roles and health benefits to living cells. In addition, accurate analysis of FAs in different foods is important for the assessment of food composition, nutritive value, health effects, or food functionality. This study presents optimized gas chromatographic methods for the separation, identification, and quantification of fatty acid methyl esters (FAMEs) derived from different food lipids. The FAME analysis was carried out using a gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry detector (GC-MS) in medium polar, DB-23 column. A comparative study was conducted between two analytical techniques to evaluate their quantitative results. Separate method parameters were developed for the separation of short-chain and long-chain FAs in both instruments. Satisfactory separation of more than 50 peaks including saturated, monounsaturated, and polyunsaturated fatty acids was determined with the optimized methods in less than 50 min. In addition, 15 FAMEs including different FAs structures were tentatively identified. The obtained results provide valuable insights into FAs composition in different lipid sources and their elution order. The quantitative results between the two gas chromatographic methods differed slightly mainly in the proportion of saturated fatty acids. Furthermore, no impact on the FAs composition was observed regardless of instrument and detector types.