The MS 1 data acquired for the LOD value comparison was analyzed and evaluated with Skyline (v21.2) . The actual concentrations of the analytes were calculated using the area of their chromatographic peaks and a 1/x weighted calibration curve. Standard addition was applied and evaluated in Excel if a chromatographic peak was present in the blank samples of the calibration curve. The concentrations of the detected analytes in the case study samples were corrected for extraction efficiency using values previously determined and dilution factor.