## 3 Results and Discussion
### Method Evaluation

Table 6: Milk powder, proficiency test 5161 (FAPAS), September 2022. \begin{table}
\begin{tabular}{c c c c} \hline
**Component** & **Assigned Value (\(\mu\)g/kg)** & **Result (\(\mu\)g/kg)** & **z-Score** \\ \hline Azoxystrobin & 36.5 & 43.3 & 0.8 \\ \hline Carbendazim & 46.2 & 51.3 & 0.5 \\ \hline Carbofuran & 62.4 & 69.6 & 0.5 \\ \hline Clothianidin & 77.0 & 83.8 & 0.4 \\ \hline Cyprodinil & 42.7 & 45.9 & 0.3 \\ \hline Dimethoate & 57.1 & 62.8 & 0.5 \\ \hline Dimethomorph (sum of isomers) & 87.8 & 88.6 & 0.0 \\ \hline Emamectin (as emamectin benzoate & 61.1 & 72.3 & 0.8 \\ Bla, expressed as emamectin) & 61.1 & 72.3 & 0.8 \\ \hline Monocrotophos & 47.5 & 50.9 & 0.3 \\ \hline Omethoate & 78.6 & 83.7 & 0.3 \\ \hline Tetraconazole & 75.5 & 82.7 & 0.4 \\ \hline Triflovstrobin & 112 & 118 & 0.3 \\ \hline \end{tabular}
\end{table} 
Table 4: Green bean puree, proficiency test 19,310 (FAPAS), April 2021. \begin{table}
\begin{tabular}{c c c c} \hline
**Component** & **Assigned Value (\(\mu\)g/kg)** & **Result (\(\mu\)g/kg)** & **z-Score** \\ \hline Atrazine & 39.3 & 47.2 & 0.77 \\ Azoxystrobin & 172 & 192 & 0.48 \\ Bocalid & 50.2 & 80.9 & 2.23 \\ Cumaphos & 51.4 & 52.8 & 0.11 \\ Lunaron & 75.3 & 75.1 & \(-\)0.01 \\ Pyrimethanil & 70.5 & 47.9 & 0.71 \\ Triadimefon & 96.9 & 99.8 & 0.13 \\ \hline \end{tabular}
\end{table} 
Table 5: Lettuce, proficiency test VF1700P (Test Veritas), October 2021.  
chromatogram of atrazine-desethyl in the date seed coffee sample we observed signals at the same retention time on both scanned ion transitions of atrazine-desethyl under screening analysis (Figure 1). The IR calculated in neat standard solution was 8.5%, so the \(\pm\)30% tolerance limit set in SANTE guideline gave an acceptable range between 6.0% and 11.1% for IR [19]. The IR for atrazine-desethyl in the coffee sample was 14.9%, so the identification did not meet the criteria and the sample was compliant. In this case the SANTE criteria appropriately excluded the presence of atrazine-desethyl in the sample [19]. Also, atrazine could not be detected in the sample. Ruling Out the False Identification of Primisulfuron-Methyl in a Herb Extract Sample with the Help of the Third MRM Transition  
During the screening analysis of an ethanolic herb extract, the positive identification of primisulfuron-methyl was evaluated based on the retention time (\(\pm\)0.1 min) and IR (\(\pm\)30%) criteria. The IR (\(m/z\) 469 \(>\) 254 and \(m/z\) 469 \(>\) 135) of primisulfuron-methyl in standard solution was 15.7%, while the IR of the appearing peak at the same retention time in the sample was 14.7% (Figure 2a). The secondary ion trace (\(m/z\) 469 \(>\) 135) showed high background noise, so the decision on whether this qualifier ion transition should be considered was made with the confirmatory method (Figure 2b,c). Furthermore, a third ion transition (\(m/z\) 469 \(>\) 199) was also set for the target compound. Figure 1: Screening analysis of a date seed coffee sample. The IR (8.5%) of ion transitions of atrazine-desethyl in a neat solvent calibrant (100 ng/mL, above) excluded the presence of it in the sample (below). Figure 2: _Cont._  
Under the confirmatory analysis, the noise level of secondary ion trace decreased. The IR of \(m/z\) 469 \(>\) 254 and \(m/z\) 469 \(>\) 135 ion transitions in the spiked samples were between 19.8% and 20.1%, so the compound could still be identified as primisulfuron-methyl. However, no peak appeared in the non-fortified samples on the third ion transition (\(m/z\) 469 \(>\) 199); only the sample spiked at 0.010 mg/kg (Figure 2b,c) showed this trace. In this case, involving a third MRM transition was required to make a correct evaluation, similarly to what [PERSON] et al. presented in their study [22]. Ruling Out the False Identification of Mylobutanil in White Peppercorn (Piper nigrum) Sample with the Help of the A + 2 Isotopologue Based MRM Transition  
The screening analysis of a white peppercorn sample showed positive identification for myclobutanil.