Triple quad mass spectrometer

The MS experiment was performed using a LCMS Xevo-TQD system including an Acquity model UPLC and a triple quad mass spectrometer (Waters, Massachusetts, USA). The positive electrospray ionization (ES+) channel was used for analysis.

UHPLC-MS/MS system was equipped with an UHPLC separation module (Acquity UPLC I-Class PLUS, Waters, Milford, MA, USA) and a triple Quad mass spectrometer. The Acquity BEH–C₁₈ column (50 mm × 2.1 mm, 1.7 μm) combined with 5 mM ammonium acetate with 0.05% ammonia (pH 8.8) (A) and acetonitrile (B) was used for the separation with gradient elution (0–0.5 min, 5% B; 0.5–5 min, 5%–95% B; 5–9 min, 95% B). The flow rate was set at 0.3 mL/min, the injection volume was 2 μL, and the column temperature was set at 45 °C.
The mass spectrometry was performed on triple Quad 6500 plus mass spectrometer (Sciex, Boston, MA, USA). The parameters of the ES ion source in positive mode were set as follows: voltage 5500 V, curtain gas (CUR) 35 psi, spray gas (GS1) 50 psi, auxiliary heater (GS2) 50 psi, ionization temperature (TEM) 550 °C, the dwell-time values 0.2 s. The MS data recordings were carried out in multiple reaction monitoring (MRM) mode and the scanning time was 0.5 s. The declustering potential (DP), collision energy (CE) and transitions for each of the analytes and for internal standard were shown in Table 5.