## 2 Materials and Methods
### Experiments on the Reduction of Residues by Means of Fining Agents
For this, 6.5 g of extraction mixture (4.0 g magnesium sulfate, 1.0 g sodium chloride, 1.0 g trisodium citrate dihydrate, and 0.5 disodium citrate sesquihydrate), 10 mL of the sample, and 30 \(\upmu\)L of the internal standard (triphenyl phosphate, 100 \(\upmu\)g/L) were added to a 50 mL centrifuge tube; after doing so, 5 mL ethyl acetate was added. The mixture was then vortexed (Vortex-Genie 2T, Scientific Industries, Bohemia, NY, USA) until the end of heat release and then centrifuged at 4700 rpm for 10 min (Heraeus Megafuge 40 R, Thermo Scientific (now Thermo Fisher Scientific), Waltham, MA, USA). 5 mL of the upper phase were collected into a 15 mL centrifuge tube with 1.05 g clean-up mixture PSA (0.15 g CHROMBOND diamino and 0.9 g magnesium sulfate) and vortexed for 1 min and then centrifuged at 7000 rpm. The supernatant was quantitatively transferred to a 25 mL round bottom flask and acidified with 40 \(\upmu\)L formic acid (5% in ethyl acetate) and completely evaporated using a rotary evaporator (Laboxact-Vacuum System Manual VP8 VAC, KNF Neuberger GmbH, Freiburg, Germany). The precipitate was dissolved with 0.5 mL of solvent (acetone: ethyl acetate = 1:1). 100 \(\upmu\)L of the resulting solution were transferred to a 300 \(\upmu\)L GC vial and subsequently analyzed. The analysis was performed using a gas chromatograph (type 7890 B A, Agilent Technologies, Santa Clara, CA, USA) with an injector, a controller, a CTC Analytics autosampler (Zwingen, Switzerland)), and a triple quad mass spectrometer (TQMS) detector (type, 7010B GC/MS Triple Quad) (Agilent Technologies, Santa Clara, CA, USA). Separation was performed using an HP-5 MS column (30 m \(\times\) 0.25 mm I.D. \(\times\) 0.25 \(\upmu\)d; Agilent Technologies, Santa Clara, CA, USA) at a column flow rate of 1.02 mL/min. Helium was used as the transport gas. The injection volume was 1 \(\upmu\)L, in split mode (50:1), and the injector temperature was 280 \({}^{\circ}\)C. The oven temperature gradient started with 60 \({}^{\circ}\)C for 1 min, was then increased to 120 \({}^{\circ}\)C with increments of 40 \({}^{\circ}\)C/min, and then heated up by another 5 \({}^{\circ}\)C/min until a temperature of 310 \({}^{\circ}\)C was reached. The total run time was 40.5 min, and the temperature in the transfer line and TQMS was 280 \({}^{\circ}\)C. The analysis was performed in multiple reaction monitoring (MRM) mode. The retention time, ion transitions, ionization energy, and validation information can be found in the Supplementary Data: Table S3. The calibration was performed with nine different concentration levels from 0.30 \(\upmu\)g/L-300.00 \(\upmu\)g/L in the unblended zero sample of the white organic experimental wine. The sample preparation for the calibration was carried out under the same conditions as mentioned above. All analyses were performed in duplicate. The determination of the limit of detection and limit of quantification was performed according to DIN 32645 from the calibration by repeating the calibration six times [51]. The intraday repeatability was calculated by 10-fold repetition of the control variant (with 50 \(\upmu\)g/L spiked sample, see chapter \"Reduction experiments by finings\"). Recovery was also determined from the same sample. Recovery was also determined to estimate the matrix effect in the red zero sample. The EU criteria for pesticide validation were used to evaluate the method [52]. According to these criteria the recovery should be in the range of 70-120%. This was achieved with the exception of pyrimethanil and cyprodinil. The relative standard deviation (RSD) of the repeatability should be less than 20%. This was also achieved for all compounds with the exception of chlorpyrifos-methyl. The limit of quantification (LOQ) of the method was below 15 \(\upmu\)g/L for all compounds (except chlorpyrifos and folpet), which corresponded to a reduction of >70% in the fining tests (spiking with 50 \(\upmu\)g/L standard) for all residues.