Calibration curves were established applying the method of standard additions: the samples were fortified with known amounts of analytes before sample preparation with the LOQs to be the lowest levels for each analyte. This calibration method was selected in order to compensate for potential matrix effects occurring during sample preparation and analysis. The calculated calibration curves (seven points, each calibration point was deter-mined in triplicate) gave a high level of linearity for all target analytes with coefficients of determination (R2) ranging between 0.9950 and 0.9999. Moreover, residual plots were prepared for each analyte. Individual residuals were scattered randomly above and below zero, with standard deviations ranging from 0.33% to 7.5%,lower than ±20% (±10% when the Maximum Residue Limit—MRL isapproached or exceeded) from the calibration curve, as suggested by SANCO/12571/2013 document.