Flow-modulated Comprehensive Two-dimensional Gas Chromatography-Triple Quadrupole Mass Spectrometry Elucidation of the Fatty Acids and Unsaponoable Constituents of Oil Derived from Lemon Seeds, A Food-Industry Waste Producy

This article is focused on the detailed qualitative analysis of the fatty acids and the unsaponifiable constituents of a vegetable oil derived from a food-industry waste product, namely lemon seeds. The seed oil was subjected to two sample preparation processes, the first enabling the formation of fatty acid methyl esters (FAMEs), and the other the isolation of the constituents of the entire unsaponifiable fraction (sterols, hydrocarbons, vitamins, etc.). Both sets of compounds were subjected to flow-modulation comprehensive two-dimensional gas chromatography– mass spectrometry (GC×GC–MS), with identification performed through full-scan data. Relative percentage data, relative to FAMEs and sterols, were derived through gas chromatography–flame ionization (GC–FID). Finally, a sterol identified through a clear signal as cholesterol, was subjected to absolute quantification using multiple reaction monitoring (MRM).