Gas chromatographic–tandem mass spectrometric identification of phenolic compounds in Sicilian olive oils Original Research Article

Phenolic compounds in Sicilian olive oils were analyzed by GC–MS and GC–MS/MS after extraction with methanol:water 80:20 and derivatization with bis(trimethylsilyl)trifluoracetamide and trimethylchlorosilane (BSTFA:TMCS 99:1). Numerous compounds were detected and 23 were identified. Tyrosol, hydroxytyrosol and the decarbomethoxy ligstroside and oleuropein aglycons in the dialdehydic forms were the most abundant compounds. 4-(Acetoxyethyl)-1-hydroxybenzene, 3,4-dihydroxyphenylacetaldehyde, syringaldehyde and the cis form of ferulic acid were identified: these compounds were not found in olive oils before. The presence of the dialdehydic form of elenolic acid (without carbomethoxy group) linked to 3-methoxy-4-hydroxyphenylethanol was hypothesized. There were quantitative differences in oils from the varieties Nocellara del Belice, Santagatese and Cerasuola; these differences could depend on the olive varieties and ripeness.