Tqs mass spectrometer system

The UHPLC analysis was performed via a Waters ACQUITY Ultra High-Performance LC system (Waters, Milford, MA, USA). Separation was achieved on an XBridge^® BEH C₁₈ column (3.0 mm × 100 mm, 2.5 µm) at 40 °C with a flow rate of 0.4 mL min⁻¹. The mobile phase consisted of methanol (A) and water containing 5 mmol L⁻¹ ammonium acetate (B). A linear gradient elution program was set as follows: initial 10% A; 1 min, 10% A; 5 min, 90% A; 6 min, 90% A; 6.5 min, 10% A; 8 min, 10% A. The injection volume was 3 µL.
For the MS/MS analysis, a Waters TQS mass spectrometer system (Waters, Milford, MA, USA) was used in positive electrospray ionization mode (ESI⁺) with the following parameters: interface voltages of capillary, 2.5 kV; source temperature, 150 °C; desolvation temperature, 500 °C. The nebulizing gas and desolvation gas flow rates were 7.0 bar and 1000 L/h, respectively. Multiple reaction monitoring (MRM) mode was used for the quantification and confirmation of the ATs with the parameters shown in Table 3.

UHPLC analysis was performed on a Waters ACQUITY Ultra High-Performance LC system (Waters, Milford, MA, USA). Chromatographic separation was achieved on a Proshell EC₁₈ column (50 mm × 2.1 mm, 2.7 μm). The mobile phase was consisted of methanol (A) and water containing 5 mmol L⁻¹ ammonium acetate (B). A linear gradient elution program was set as follows: initial 10% A; 1 min, 10% A; 5 min, 90% A; 6 min, 90% A; 6.5 min, 10% A; 8 min, 10% A. The flow rate was 0.4 mL min⁻¹. The injection volume was 3 μL, and the column temperature was 35 °C.
For MS/MS detection, a Waters T-QS mass spectrometer system (Waters, Milford, MA, USA) was used both in positive electrospray ionization mode (ESI⁺) and in negative electrospray ionization mode (ESI⁻) with the following parameters: interface voltages of capillary, 2.5 kV(ESI⁺) and 1.5 kV(ESI⁻); desolvation temperature, 500 °C; and source temperature, 150 °C. The gas flow rates were 7.0 bar for nebulizing gas and 1000 L h⁻¹ for desolvation gas, respectively. Multiple reaction monitoring (MRM) mode was used for the quantification and confirmation of the Alternaria toxins with the parameters shown in Table 1.