Xcalibur data

The chemical constituents in EG ethanolic extract were analyzed by ESI-MS [54 (link)] using a linear trap (LTQ) mass spectrometer–coupled electrospray ion source (Thermo Scientific, Waltham, MA, U.S.A.), which was associated with the Xcalibur data-processing system. The spray ionization voltage was 4 kV in positive ion detection mode. The capillary temperature was 200 °C, the capillary voltage was 35 V, and the tube lens voltage of the LTQ-MS was 110 V. The EG extract was dissolved in extractant (ethanol:water = 60%:40%), diluted to 1 ppm solution (used as a spray reagent), and then filtered. A 2 μL/min flow rate was applied to the 1 ppm spray reagent to pass through a quartz capillary tube. The spray solvent became charged reagent droplets in an electric field with a 0.6 MPa nitrogen sheath gas flow, which was followed by the desolventization to generate ions for subsequent MS analysis. The mass spectral scanning range was m/z 50 to 1000. The width of the parent ion isolation was 1.0–1.2 Da, and the collision energy was 15–40%.