## 3 Results  
In summary, this is a novel sample preparation method utilizing the addition of n-hexane and sample evaporation, coupled with GC-QqQ-MS/MS, for the multi-class determination of pesticide residues in edible oils, providing the possibility of effectively removing matrix components. The analytical method was validated according to a plan based on the criteria of document SANTE/11312/2021 V2. Calibration curves were prepared in a matrix with a high oil content and low to moderate water content (oil). Recovery studies were conducted at two levels of concentrations, LOQ and 5 \(\times\) LOQ, with concentration ranges consistent with Table S2. Based on the obtained results, the following validation parameters were determined: LOQ, recovery, repeatability, linearity, matrix effect, and expanded uncertainty (Table S1). The utilization of three-stage solvent extraction results in the dilution of the extract, which may lead to a significant reduction in signal intensity during direct analysis. Consequently, the application of final extract evaporation becomes necessary. Substituting the final solvent with a toluene-acetone mixture in a ratio of 9:1 enables excellent dissolution of all analytes. The selection of the necessary pesticide analytes was based on the guidelines provided by the European Commission, Regulation 396/2005, taking into account the maximum complexity and chemical diversity, as well as laboratory availability. The compounds were identified through injection of a standard mixture, taking into account the retention time with a permissible difference of 0.1 min and MRM ion transition ratios within \(\pm\)30%. The limit of quantification (LOQ) for each pesticide was established at the lowest calibration level corresponding to the concentration of a single pesticide yielding a signal-to-noise ratio greater than 10. Meanwhile, the limit of detection (LOD) value was consistently higher than 3. Linearity was evaluated in the range of 0.002 to 0.5 mg kg\({}^{-1}\), with coefficients of determination ranging from 0.995 to 0.9999. Recovery was assessed by analyzing enriched samples at the LOQ and 5 \(\times\) LOQ concentration levels, according to Table S2. Recoveries ranged from 35% to 116%, as shown in Table S2. Recoveries below 30% were obtained for nine compounds: chlorotoluron, dichlorobenzene, 4,4\({}^{\prime}\)-dichlor, nitralin, pentachlorophenol, piperophos, propchiazofop, terbacil, tetrachlorvinphos, and thiometon. Meanwhile, the criterion of RSD \(\leq\) 20% was exceeded for 21 compounds: bifenazate, chinomethionat, chlorotluron, cypermethrin, disulfoton sulfoxide, dodecmorph, ethofumesate, fenamiphos sulfone, fenhexamid, fenmedifam, fenoxaprop-ethyl, fenpropidin, fenpropimorph, fenthion oxon sulfone, furathiocarb, furilazole, pendimethalin, phosmet, pyridalyl, spiroxamine, and trinexapac ethyl. Furthermore, the recovery of aldrin, biphenyl, bromociclen, carbofuran, chlorothalonil, endrin, folpet, heptachlorobenzene, pentachloroaniline, proquinazid, quinocetone, and quinoxofen analytes was found to be below the 70-120% range. Nevertheless, these compounds were positively assessed in the validation experiment due to their relative standard deviation (RSD) being \(\leq\) 20%, and thus they were included in the analysis. The matrix effect was examined for all analyzed compounds, representing the ratio between the slope of the calibration curve in the matrix and the slope of the calibration curve in the solvent. For 14 pesticides, the matrix effect was lower than 20%; in the range of 20-50%, this effect was observed for 73 pesticides, and a value above 50% was noted for 207 pesticide residues. The assessment of method robustness revealed that employing a two-step extraction of the analytical sample increased the analyte recovery by 15%. A prolonged 20 min mixing duration was necessary to achieve satisfactory results.