Vion im qtof mass spectrometer

By employing ACQUITY™ UPLC system (Waters, Milford, USA), chromatographic separation was carried out on an ACQUITY™ UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) held at 40 °C. The mobile phase consisted of 0.2% formic acid aqueous solution (A) and acetonitrile (B) with a flow rate of 0.3 mL/min using a gradient elution of 3%–10% B between 0 and 2 min, 10%–20% B between 2 and 3 min, 20%–28% B between 3 and 7 min, 28%–45% B between 7 and 7.5 min, 45%–90% B between 7.5 and 20 min, and 90%–3% B between 20 and 21 min. The injection volume was 5 μL.
The MS analysis was performed on a Vion IM-Q TOF mass spectrometer (Waters Corporation, Milford, USA) using electrospray ionization (ESI) in both positive and negative ion modes. MS conditions were as follows: the capillary voltage at 3.0 and −2.5 kV in positive and negative ion modes, respectively; the source temperature at 120 °C; the temperature of the desolvation gas at 400 °C; the flow rate of the desolvation gas (N₂) at 700 L/h; the flow rate of the cone gas (N₂) and collision gas (Ar) at 50 L/h and 0.20 mL/min, respectively; mass range: m/z 150–1500; collision energy, 6 eV and 20–60 eV ramping. Data acquisition was controlled with UNIFI 1.8.0 informatics platform (Waters Corporation, Milford, USA).