Evaluation of the QuEChERS extraction approach for the analysis of active compounds of pharmaceuticals in olive tree portions

Background: A modified version of the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method has been tested for quantifying six active compounds of pharmaceuticals (PhACs), i.e., two different antibiotics, two anti-inflammatories, one antifungal, and one anti-depressant, extracted from roots, leaves and stems, pulp, pits, and oil obtained from olive trees. The different matrices have been polluted with all contaminants at 25, 50, and 250 µg L−1 and the recoveries were determined by liquid chromatography tandem–mass spectrometry. The validation of the method has been carried out by determining linearity, recovery, precision, limits of detection (LODs), and limits of quantification (LOQs) values. A matrix-matched calibration for each matrix has been adopted in order to avoid the matrix effect at the aforementioned levels of fortification. Results: The recoveries of PhACs from the different matrices were always above 70% and the relative standard deviation (RSD) always ≤ 20%, conditions required for the validation of the method. The LOD and LOQ values were always lower than 25 µg L−1, i.e., always lower than the minimum concentration used in the experiment; therefore, the method can be validated at 25, 50, and 250 µg L−1. Conclusions: This method can represent a valid alternative to the traditional extraction methods to quantify pharmaceuticals extracted also from fatty matrices. Graphical Abstract: [Figure not available: see fulltext.].