All sample preparation was conducted in plastic Eppendorf tubes on ice to minimize potential compound degradation. For the urine and serum/plasma samples, 200 µL were fortified with 20 µL of an internal standard mixture containing 13 isotopically-labelled xenobiotics in ACN/H2O (10/90, v/v) (Supplementary Table ). 20 µL ACN/H2O (10/90, v/v) were added (20µL of a solvent standard in ACN/H2O (10/90, v/v) were used in spiking experiments for method validation), followed by 770 µL ACN/MeOH (1/1, v/v). For extraction, samples were sonicated for 10 min on ice. Proteins were precipitated for 2 h at -20°C and the samples were then centrifuged for 10 min at 18,000  g at 4°C. The supernatant was transferred and dried in a vacuum concentrator at 4°C overnight. The residue was reconstituted in 200 μL ACN/H2O (10/90, v/v). Afterwards the samples were again vortexed and centrifuged for 10 min at 18,000  g at 4°C. The supernatant was finally transferred to amber glass vials for LC-MS/MS measurement and stored at -20°C until analysis.