*4.6. LC-MS*/*MS Analysis*

The analysis was performed with a Nexera X2 system with an LCMS-8050 triple-quadrupole mass spectrometer (Shimadzu, Kioto, Japan). LabSolutions software (version 5.60 SP2, Shimadzu, Kioto, Japan) was used for data acquisition and processing. Chromatographic separation was tested using four chromatographic columns with the different stationary and mobile phase composition (Table S2). Column and autosampler temperatures were set at 45 ◦C and 4 ◦C, respectively. The final optimised mobile phase A consisted of 0.2% CH3COOH in water/ACN (95:5; *v*/*v*) (eluent A) and ACN/0.2% CH3COOH in water (95:5; *v*/*v*) (eluent B). A gradient elution was used as follows: 0–2 min 15% B, 2.1–6 min 18% B, 6.1–9 min isocratic step at 100% B, and 9.1–12 min 0% B. The total run time was 12 min at a flow rate of 0.3 mL/min and the injection volume was 5 µL.

The mass spectrometry detection was carried out using multiple reaction monitoring (MRM) with positive and negative electrospray ionization (ESI+/−) (Table S2). The following ion-source settings were used: nebulising gas flow: 2 L/ min, heating gas flow: 10 L/min, drying gas flow: 10 L/min, interface temperature: 300 ◦C, desolvation line temperature: 250 ◦C, heat block temperature: 400 ◦C, and Q1 and Q3 resolution: Unit.

The identification of the analyte was performed according to the SANTE/12089 /2016 Guidance document on identification of mycotoxins in food and feed [50]. Four identification criteria were used: comparison of peak retention time in test samples with retention times of calibration standards; the retention time of the internal standard being within the tolerance range ±0.05 min relative to the appropriate standard; selection of at least two characteristic fragmentary ions and calculation of their ion ratio (within ±30% (relative) of average of calibration standards from the same sequence); and the peaks having an S/N ratio of at least 3.
