Determination of phenolic compounds in olive oil: New method based on liquid–liquid micro extraction and ultra high performance liquid chromatography-triple–quadrupole mass spectrometry

Abstract

A novel analytical approach has been performed and evaluated for the identification and quantification of phenolic compounds (phenolic alcohols, secoiridoid derivates, lignans, flavonoids, phenolic acids and aldehydes) which can be found in both virgin olive oil (VOO) and extra virgin olive oil (EVOO). An improved liquid–liquid micro extraction (LLME) method combining with ultra high performance liquid chromatography (UHPLC) coupled to electrospray ionization source (ESI) and tandem mass spectrometry (MS/MS) in Dynamic Multiple Reaction Monitoring (DMRM) mode has been developed, reducing the amount of sample, reagents and time consumed. The proposed methodology was applied to standard solutions, and the quality control parameters obtained were compared with those achieved in spiked refined olive oil (SROO). Generally, these parameters showed lower values in SROO than in standard solutions. Matrix effect, recovery and process efficiency have been studied using SROO. The recoveries were around 90% and the process efficiency of the whole method was higher than 80% for most of the phenolic compounds studied. Examination of these parameters revealed that work straight in the olive oil matrix, which is closer to behave as a real sample, provides better results. The applicability and reliability of this methodology have been confirmed using real samples.