## 3 Results
### Method Validation
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **LOD** & **LOQ** & **LOD** & **LOQ** & **Recovery**\(\pm\) & **Uncertainty** \\ \cline{3-6}
**Analyte** & **t\({}_{\text{R}}\)****a** **(min)** & **u\({}_{\text{B}}\)****L\({}^{-1}\)** & **u\({}_{\text{B}}\)****L\({}^{-1}\)** & **u\({}_{\text{B}}\)****kg\({}^{-1}\)** & **u\({}_{\text{B}}\)****kg\({}^{-1}\)** & **u\({}_{\text{B}}\)****kg\({}^{-1}\)** \\ \cline{3-6}  & & **Solvent****b** & **Matrix: Wheat****c** & **(\%)** & **(\%)** \\ \hline Aldrin & 14.47 & 0.138 & 0.418 & 0.154 & 0.466 & 74.8 \(\pm\) 8.6 & 11.5 \\ Azinphos-ethyl & 23.26 & 0.080 & 0.243 & 0.086 & 0.259 & 110.3 \(\pm\) 6.5 & 10.2 \\ cis-Chlordane & 16.85 & 0.109 & 0.329 & 0.083 & 0.251 & 70.6 \(\pm\) 7.7 & 23.1 \\ trans-Chlordane & 16.40 & 0.115 & 0.349 & 0.143 & 0.381 & 77 \(\pm\) 12 & 23.8 \\ Chlorfenvinphos & 15.90 & 0.020 & 0.060 & 0.147 & 0.446 & 96.3 \(\pm\) 6.1 & 15.3 \\ Chlorpyrifos & 14.66 & 0.015 & 0.045 & 0.057 & 0.173 & 97.7 \(\pm\) 8.7 & 16.2 \\ Chlorpyrifos-methyl & 13.22 & 0.129 & 0.389 & 0.093 & 0.282 & 91.8 \(\pm\) 6.0 & 15.5 \\ Cyfluthin & 24.57 & 0.063 & 0.192 & 0.122 & 0.369 & 107 \(\pm\) 15 & 3.3 \\ Cypermethrin & 25.05 & 0.081 & 0.245 & 0.168 & 0.510 & 109 \(\pm\) 11 & 14.6 \\ P.p\({}^{\prime}\) DDD & 18.77 & 0.048 & 0.144 & 0.114 & 0.344 & 78.3 \(\pm\) 4.8 & 7.4 \\ P.p\({}^{\prime}\) DDE & 17.49 & 0.130 & 0.394 & 0.025 & 0.077 & 74.9 \(\pm\) 5.0 & 13.9 \\ P,p\({}^{\prime}\) DDT & 19.87 & 0.186 & 0.565 & 0.101 & 0.306 & 71 \(\pm\) 10 & 5.9 \\ Deltamethrin & 27.25 & 0.152 & 0.460 & 0.018 & 0.056 & 104 \(\pm\) 14 & 6.7 \\ Diazinon & 11.78 & 0.107 & 0.324 & 0.037 & 0.113 & 97 \(\pm\) 11 & 20.2 \\ Dieldrin & 17.54 & 0.148 & 0.450 & 0.035 & 0.106 & 77.2 \(\pm\) 6.6 & 13.7 \\ \(\alpha\)-Endosulfan & 16.76 & 0.111 & 0.337 & 0.106 & 0.322 & 79.6 \(\pm\) 5.3 & 15.5 \\ \(\beta\)-Endosulfan & 18.50 & 0.134 & 0.406 & 0.078 & 0.237 & 83.0 \(\pm\) 5.3 & 9.9 \\ Endosulfan sulphate & 19.77 & 0.174 & 0.527 & 0.121 & 0.367 & 92.6 \(\pm\) 8.1 & 16.8 \\ Endrin & 18.20 & 0.170 & 0.515 & 0.160 & 0.484 & 83 \(\pm\) 14 & 15.4 \\ Fenthion & 14.62 & 0.035 & 0.107 & 0.068 & 0.207 & 86 \(\pm\) 11 & 10.1 \\ Fenvalerate & 26.34 & 0.038 & 0.115 & 0.117 & 0.353 & 104 \(\pm\) 11 & 13.2 \\ \(\alpha\)-HCH & 10.48 & 0.151 & 0.458 & 0.075 & 0.226 & 81.3 \(\pm\) 9.7 & 7.8 \\ \(\beta\)-HCH & 11.36 & 0.111 & 0.335 & 0.061 & 0.186 & 81.6 \(\pm\) 9.1 & 10.2 \\ \(\gamma\)-HCH & 11.40 & 0.142 & 0.430 & 0.084 & 0.255 & 82 \(\pm\) 10 & 8.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Performance and chromatographic parameters of pesticides analyzed by GC-MS/MS. Method selectivity was tested by the analysis of 20 independent blank samples. The absence of interfering peaks in the retention time window of interest within a time tolerance of 0.2 min was checked for each analyte by comparing the chromatographic profiles obtained for blank and spiked samples. The trueness of measurements was assessed in accordance with Decision 2002/657/EC through the analysis of spiked samples, prepared starting from blank material by additions of known amounts of the analytes. Precision and recovery were determined by performing tests on two sets of blank wheat (six replicates each), fortified at a concentration of 0.025 mg kg\({}^{-1}\) for each analyte. Recovery percentages were calculated by comparing the concentration of spiked samples, calculated through the calibration line, with the nominal fortification level. It was verified that the calculated mean recovery for each pesticide complied with the recovery range of 70-120%, reported in the official documents (European Commission SANTE 2017/11813/EC) dealing with the method validation and quality control procedures for Pesticide Residues Analysis in Food and Feed. The intra-day RSDr values were well below the reference values of 20%, derived by Horwitz equation [29], under repeatability conditions, demonstrating a good method precision.