## 3 Results
### Method Validation
#### 3.2.2 Trueness and Precision  
Results for precision and accuracy (expressed as repeatability and intermediate precision) are given in Table 4.  
All the results for precision and trueness indicate the good performance of the developed method. Trueness was assessed by performing recovery studies, with values ranging from 87.5% (FCM no. 766) to 102.7% (FCM no. 808) for the repeatability and from 88.6%(FCM no. 808) to 101.2% (FCM no. 808) for the intermediate precision. Moreover, pre \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{3}{*}{**Analyte**} & \multirow{3}{*}{\begin{tabular}{c} **Theoretical Added** \\ **Amount** \\ **(ng mL\({}^{-1}\))** \\ \end{tabular} } & \multicolumn{3}{c}{**Repeatability**} & \multicolumn{3}{c}{**Reproducibility**} \\ \cline{2-10}  & & \begin{tabular}{c} **Experimental** \\ **Amount** \\ **(ng mL\({}^{-1}\))** \\ \end{tabular} & \multirow{2}{*}{**SD**} & \multirow{2}{*}{**SD**} & \multirow{2}{*}{**Resovery**} & \multirow{2}{*}{\begin{tabular}{c} **Experimental** \\ **(\%)** \\ \end{tabular} } & \multirow{2}{*}{**SD**} & \multirow{2}{*}{**\
\begin{tabular}{c} **RSD** \\ **(\%)** \\ \end{tabular} } & \multirow{2}{*}{**
\begin{tabular}{c} **Recovery** \\ **(\%)** \\ \end{tabular} } \\ \cline{2-10}  & & 20 & 19.4 & 0.4 & 2.2 & 97.2 & 19.9 & 7.0 & 7.2 & 99.5 \\ \cline{2-10} FCM no. 674 & & 100 & 99.4 & 4.7 & 4.7 & 99.4 & 97.0 & 3.7 & 3.8 & 97.0 \\ \cline{2-10}  & & 400 & 357.2 & 30.0 & 8.4 & 89.3 & 372.8 & 9.3 & 11.2 & 93.2 \\ \hline \multirow{3}{*}{FCM no. 752} & & 20 & 19.5 & 0.2 & 1.1 & 97.5 & 19.9 & 3.1 & 3.2 & 99.6 \\ \cline{2-10} FCM no. 752 & & 100 & 95.2 & 5.2 & 5.5 & 95.2 & 98.7 & 6.0 & 6.4 & 98.7 \\ \cline{2-10}  & & 400 & 354.4 & 30.5 & 8.6 & 88.6 & 364.4 & 8.8 & 10.9 & 91.1 \\ \hline \multirow{3}{*}{FCM no. 766} & & 20 & 19.5 & 0.7 & 3.8 & 97.4 & 20.1 & 5.1 & 5.2 & 100.4 \\ \cline{2-10}  & & 100 & 96.4 & 6.8 & 7.1 & 96.4 & 98.6 & 5.3 & 5.6 & 98.6 \\ \cline{2-10}  & & 400 & 350.0 & 42.7 & 12.2 & 87.5 & 357.6 & 9.2 & 11.8 & 89.4 \\ \cline{2-10}  & & 20 & 19.4 & 0.4 & 2.2 & 96.8 & 20.2 & 4.8 & 4.9 & 101.2 \\ \cline{2-10} FCM no. 808 & & 100 & 102.7 & 5.3 & 5.2 & 102.7 & 99.5 & 5.7 & 5.6 & 99.5 \\ \cline{2-10}  & & 400 & 364.4 & 31.7 & 8.7 & 91.1 & 354.4 & 9.5 & 11.8 & 88.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Repeatability and reproducibility results for all the target analytes in food simulant D1 (50% % ethanol in H\({}_{2}\)O). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Analyte**} & \multirow{2}{*}{\begin{tabular}{c} **Retention Time** \\ **(min)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Selected Ion** \\ **(\(m/z\))** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Linear Regression** \\ **Coefficient** \\ **(R\({}^{2}\))** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **LOD** \\ **(ng mL\({}^{-1}\))** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **LOQ** \\ **(ng mL\({}^{-1}\))** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Upper Linear Limit** \\ **(ng mL\({}^{-1}\))** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Matrix Effect** \\ **(ME,\%)** \\ \end{tabular} } \\ \hline FCM no. 674 & 2.24 & 359.149 & 0.990 & 4.9 & 16.2 & 500 & 1.2 \\ FCM no. 752 & 3.57 & 387.180 & 0.992 & 1.1 & 3.6 & 500 & \(-2.1\) \\ FCM no. 766 & 5.51 & 415.211 & 0.991 & 1.3 & 4.5 & 500 & \(-1.1\) \\ FCM no. 808 & 11.11 & 485.290 & 0.993 & 2.0 & 6.8 & 500 & 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Analytical features of the validated analytical method. cision results revealed RSDs ranging from 1.1% (FCM no. 752) to 12.2% (FCM no. 766) for repeatability results and from 3.2% (FCM 752) to 11.8% (FCM 808) for reproducibility [19]. It was, however, noted a general trend of a decrease of recoveries and increase of RSDs (%) as the concentration level is closer to the upper linear limit (500 ng mL\({}^{-1}\)).