Lipidomics investigation of Sicilian pistachio (Pistacia vera L. var. Bronte) by microwave-assisted extraction, solid-phase extraction/fractionation, GC-FID, and UHPLC-APCI-MS analyses.

In this work, an integrated chromatographic platform combining microwave-assisted extraction (MAE), aminopropyl solid-phase extraction/fractionation (SPEF), gas chromatography with flame ionization detection (GC-FID), and ultra-high-performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry (UHPLC-APCI-MS) was developed and applied to Sicilian Bronte pistachio (Pistacia vera L.) seeds. The methyl tert‑butyl ether (MTBE)-based procedure allowed rapid lipid extraction, while the SPEF protocol enabled the selective isolation of triacylglycerols (TAGs), free fatty acids (FFAs), and phospholipids (PLs). Fractionation significantly reduced matrix complexity and enhanced the characterization of both abundant and minor lipid classes. UHPLC-APCI-MS analysis allowed the putative identification of 31 TAGs together with several phosphatidylcholine (PCs) and phosphatidylethanolamine (PEs) molecular species, whereas GC-FID analysis following in-vial derivatization provided detailed fatty acid profiles for each isolated fraction. The analytical workflow revealed marked differences between esterified and FFA pools and demonstrated the predominance of oleic acid-containing TAGs in Bronte pistachio oil. Moreover, the combined use of lipid-class fractionation and APCI-MS generated structurally informative fragmentation patterns that facilitated lipid determination without the need for more sophisticated techniques.