Acquity uplc beh hilic

Chromatography was performed using a DIONEX UltiMate 3000 system (Thermo Scientific) for all swab evaluation tests and a Nexera X2 (Shimadzu) was employed for the spatially resolved sampling test in human subjects. In both cases, an Acquity UPLC BEH HILIC (130Å, 1.7 μm, 2.1 mm × 100 mm) (Waters) was used. The column was kept at 40°C, and the injection volume was 2 μL. Gradient elution was performed using 10 mM ammonium acetate in water (eluent A), and acetonitrile (eluent B). The flow rate was 0.4 mL min^-1. The gradient was as follows: 0-1 min, 95% B, 9 - 10 min, 40% B, 10.5 – 17.5 min, 95 % B (equilibration). A maXis Impact HD (Q-TOF instrument, Bruker) was used for detection during all swab evaluation analyses, whereas a TripleTOF 6600 (Q-TOF instrument, Sciex) was used for the spatially resolved sampling test. The mass spectrometer was scanning from m/z 100-1000 for all MS1 experiments and, in the case of spatially resolved sampling test, from m/z 50-1000 for MS2 experiments. Measurement conditions are described in Table S1 (maXis Impact HD) and Table S2 (TripleTOF 6600).

All organic solvents, including acetonitrile and methanol used for sample extraction and ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) analysis, were LC/MS grade and purchased from Fisher Scientific. Stock standard solutions of DON, 3-ADON, and 15-ADON, in acetonitrile with concentrations of 100.0, 100.0, and 100.0 mg/L, respectively, were purchased from Romer-labs (Tulln, Austria) and stored at −20 °C. ¹³C-DON (stable isotope-labelled internal standard, 50.0 µg/ml) and ¹³C-3-ADON (stable isotope-labelled internal standard, 25.0 µg/ml) stock solutions in acetonitrile were purchased from Romer-labs (Tulln, Austria). The working standard solutions were prepared in the mobile phase and kept at 4 °C. Wheat and maize reference materials for DON were purchased from Biopure (Tulln, Austria). Purified water was obtained from a Milli-Q system (Millipore, Bedford, MA, USA). Separation of the analytes was achieved on a Waters ACQUITY UPLC BEH HILIC (2.1 × 100 mm, 1.8 µm) column. The identification of mycotoxins was performed on a 6460–1290 ultra high performance liquid chromatography mass spectrometer. The 0.22-µm pore organic phase filter membrane was purchased from Jinteng (Tianjin, China). A Mycosep 226 multi-functional purification column was purchased from Romer-labs (Tulln, Austria).