Quantitative analyses of essential fatty acids in cereals and green vegetables by isotope dilution-gas chromatography/mass spectrometry

Abstract An analytical method for the accurate determination of essential fatty acids in cereals and green vegetables is established based on isotope dilution-gas chromatography/mass spectrometry (ID-GC/MS). In this approach, 13C-labeled fatty acids were added as internal standards to the samples prior to the sample preparation. Repeatability and reproducibility for the analyses of the essential fatty acids extracted from homogenized cereals and green vegetables were examined to validate the ID-GC/MS method. The repeatability and reproducibility were within 2% relative standard deviation. The developed method provides higher-order measurement results with the relative expanded uncertainties of 1–2% and 2–4% for cereals and green vegetables, respectively. Based on the fatty acid measurements, the developed ID-GC/MS method can be used as a candidate reference method for the quantitation of essential fatty acids in cereals and green vegetables. The developed method was also applied to analyze several commercially available products including cereal and vegetable powders.