Determination of fatty acid methyl esters by GC–triple quadrupole MS using electron and chemical ionization

Abstract

Background: The main objective of this study was to explore the potential use of electron ionization (EI) and chemical ionization (CI) techniques in fatty acid measurement. MS/MS, together with main fragment ions in EI and positive CI of 37 fatty acid methyl esters (FAMEs), were investigated using a triple quadrupole mass spectrometer. Results: Our results demonstrated that several diagnostic ions of FAMEs could be confirmed using EI. On the other hand, the characteristic fragmentation patterns and probable pathway of FAMEs could be deduced from the collision-induced dissociation mass spectra when using positive CI. Owing to its capability in using the specific ions of fatty acids for selected ion monitoring and SRM, CI is considered to be more suitable for fatty acid quantitative analysis. Based on these features, a systematic strategy was then developed to integrate these fragments for GC–MS/MS for the determination of fatty acids. Conclusion: This approach offers a rapid and accurate method for measuring a wide spectrum of fatty acids.