Xevo g2 xs type qtof ms mass spectrometer

The UPLC-QTOF-MS/MS system was comprised of an Acquity Ultra-Performance Liquid Chromatography (UPLC) system and a Xevo G2-XS type QTOF-MS mass spectrometer (Waters, Milford, MA, USA). Each of the five selected crude extracts prepared above (GPS, S-1006, S-1201, S-1206 or GPE) was dissolved at a concentration of 1 mg/mL in chromatographic pure methanol, and the dissolved solution was filtered through a 0.22-μm membrane filter prior to the analysis with the UPLC under conditions exactly the same as that of the above HPLC, including the Diamonsil C₁₈ column, solvent system and gradient program, flow rate, injection volume, and column temperature. Mass spectra were recorded within the range of m/z 100–1500 in both positive and negative ionization modes under the following conditions: nitrogen drying gas flow, 10.0 L/min; nebulizer pressure, 45 psi; gas drying temperature, 370 °C; capillary and fragment or voltage, 2500 kV; and MS/MS collision energies, 20 V^{16 (link)}. The ginsenosides identified by negative ionization modes have covered those in positive modes, hence, the results were mainly based on negative ionization modes.

The UPLC-QTOF-MS/MS system comprised an Acquity Ultra-Performance Liquid Chromatography (UPLC) system and a Xevo G2-XS type QTOF-MS mass spectrometer (Waters, Milford, MA, USA). Each of the crude extracts prepared above was dissolved at concentration of 1 mg/mL in chromatographic pure methanol, and the dissolved solution was filtered through a 0.2 μm membrane filter prior to the analysis with the UPLC, in which the reversed phase column was also used, and the column temperature was also set at 25 °C. Mass spectra were recorded within the range of m/z 100–1500 in both positive and negative ionization modes under the following conditions: nitrogen drying gas flow, 10.0 L/min; nebulizer pressure, 45 psi; gas drying temperature, 370 °C; capillary and fragment or voltage, 2.500 kV; and MS/MS collision energies, 20 V.