DIRECT GC-(EI)MS DETERMINATION OF FATTY ACID ALKYL ESTERS IN OLIVE OILS

A new analytical method for fatty acid alkyl esters (FAAEs) determination by GC\u2013MS in virgin olive oils is proposed. No sample preparation is required and FAAEs are directly thermo-desorbed and cryo-focalised in the cooled injector of a GC\u2013MS (EI) instrument. The analytical conditions were optimized by Design of Experiment (DoE) techniques (an exploratory Plackett\u2013Burman design followed by a factorial design on three selected variables). After the improvement of method performances, several samples of extra virgin and low quality virgin olive oils were analyzed both by the new method and by the Of\ufb01cial EU Method of analysis. The application of Principal Component Analysis to the obtained results con\ufb01rmed that the ability of the proposed method to discriminate between extra virgin and lower quality olive oils is at least equal to that of the Of\ufb01cial Method, but the new method is faster, simpler, requires a much lower amount of organic solvents and signi\ufb01cantly enhances method repeatability