## 3 Results and Discussion
### Method Evaluation
The 208 \(>\) 172 \(m/z\) ion transition (Rt = 4.71 min) was selective enough to make the correct decision on the sample. This ion trace appeared only in the chromatogram of the spiked sample (0.010 mg/kg, below). The arrow shows the appearance of signal in the expected retention time in the fortified sample due to the spiking. Figure 6: _Cont._  
Ruling Out the False Identification of Mepanipyrim in Parsley Root (Petroselinum crispum) with the Help of the Third MRM Transition  
The positive identification of mepanipyrim was observed in parsley root during screening analysis (Figure 7a). The retention time of the analyte in neat solvent and sample extract were 9.51 min and 9.46 min, respectively. Ion ratio of the two recorded ion transitions (\(m/z\) 224 \(>\) 106, \(m/z\) 224 \(>\) 77) were 58.4% in neat solvent and 67.5% in sample extract, respectively. Estimation by the screening analysis showed the concentration of the analyte to be above current maximum residue level (MRL = 0.01 mg/kg). The estimated value was 0.026 mg/kg. To exclude the possibility of false positive identification, two additional ion transitions (\(m/z\) 224 \(>\) 205 and \(m/z\) 224 \(>\) 206) were tuned and monitored during the confirmatory analysis, however, only one ion trace (\(m/z\) 224 \(>\) 206) was selective enough for mepanipyrim in parsley root matrix (Figure 7b). Figure 1:0 (a) Screening analysis of a dried ginger sample. The ion transitions of tebufenpyrad in a neat solvent calibrant (100 ng/mL, above) and in the sample (below). (b) Confirmatory analysis of a dried ginger sample for tebufenpyrad using standard addition (0.010 mg/kg). Figures show the total ion chromatograms (TICs). (c) Confirmatory analysis of a dried ginger sample for tebufenpyrad using standard addition. The target compound elutes at 6.05 min. Ion transitions were as follows: blue line (\(m/z\) 334 \(>\) 145), green line (\(m/z\) 334 \(>\) 117), light blue line (\(m/z\) 334 \(>\) 114), purple line (\(m/z\) 334 \(>\) 91). Figure 1:1 _Cont._  
In the lack of GC-MS/MS and LC-HRMS technique for further confirmation, the application of more than two ion transitions is crucial sometimes. However, the number of ion transitions scanned using multi-methods--such as scheduled MRM or Dynamic MRM--is limited by coeluting analytes. In order to obtain enough data points for a chromatographic peak, the cycle time should not exceed a certain value, thus the number ion traces scanned simultaneously is restricted. Therefore, the pesticide multi-methods are generally used for screening samples and as the above presented examples revealed, false identification can happen if only two ion transitions are used. Hence, confirmatory analysis shall be followed after the screening and the confirmatory method shall include more ion traces than those included in the screening approach. It is also important to emphasize that the calibration in neat solvent is only usable to screen the samples, the final decision on the sample shall include standard addition or isotopically labelled analogue to obtain the appropriate retention time. The identification criteria laid down in SANTE guideline is appropriate as the current HPLC systems has a stable retention time and the MS/MS detection also gives stable IR (e.g., atrazine-desethyl) if the signal on the ion transitions can be appropriately distinguished from the noise. Improvement in identification can be achieved with HRMS or utilizing the isotope distribution of halogenated compounds (e.g., myclobutanil). However, final qualification from the screening method cannot be carried out even though the retention time and IR meet the criteria (e.g., problem). It is advised to use more than two ion transitions for the confirmatory analysis of compounds identified during screening analysis (e.g., quinoclamine, pirimisul-fon-methyl, tebufenpyrad, mepanipyrim).