Determination of polyphenolic compounds in wastewater olive oil by gas chromatography–mass spectrometry

A simple and sensitive method for the determination of 21 polyphenolic compounds in wastewater from olive oil production plants is proposed. The method involves a liquid–liquid microextraction (LLME) procedure with ethyl acetate followed by a silylation step. Identification and quantification have been performed by gas chromatography–mass spectrometry (GC–MS). MS measurements were carried out using selected ion monitoring mode (SIM). α-Naftol was used as internal standard. The proposed method was applied to the determination of these compounds in wastewater from an olive oil production factory in Jaén (Spain) at concentration levels ranging from 1.0 to 75.0 μg ml−1 for each compound. The autodegradation process by own microbiota in samples collected in three different points of the factory was also studied. The method was validated by a recovery assay with spiked samples.