Simultaneous determination of long-chain aliphatic aldehydes and waxes in olive oils

A procedure for the simultaneous determination of long-chain aliphatic aldehydes, and aliphatic and triterpenic waxes in virgin olive oils is described. A fraction containing these compounds was isolated from the oil using solid-phase extraction on silica-gel cartridges. The fraction was analyzed by capillary GC on 35%-dimethyl–65%-diphenylpolysiloxane phase using on-column injection. In extra virgin olive oils, the long-chain aliphatic aldehydes with even carbon atom numbers from C 22 to C 30 were identified by comparison of retention times and mass spectra with those of synthesized standards. The concentration of total aldehydes ranged from 20.2 to 108.0 mg/kg— n-hexacosanal being the most abundant aldehyde. The determination of aliphatic waxes was achieved with similar or better precision than that of the EU official methods.