Agilent 6540 ultra high definition accurate mass q tof lc ms system

The reaction product was concentrated by vacuum freezing for 28 h, and was resuspended in 200 μL ddH₂O. The sample was further centrifuged at 14,000 × g for 15 min and the supernatant was loaded onto an Agilent HC-C18 column (250 × 4.6 mm; 5 μm particle sizes) in the Agilent 6540 Ultra High Definition (UHD) Accurate-Mass Q-TOF LC-MS system (wavelength was set as 254 nm). The MS operating conditions were capillary Voltage 3500 V, nebulizer pressure 35 psig, the flow rate of drying gas 9 L/min and temperature 350°C. The scanning range of Q-TOF was m/z 100–1,000 under the negative-ion detection mode. Data were acquired at the rate of one spectrum per second (Xin et al., 2015 (link)).

The Agilent 6540 Ultra High Definition (UHD) Accurate-Mass Q-TOF LC/MS system from Agilent Technologies (Santa Clara, CA, USA) was used for mass spectrometry analysis. The compounds in 10 μL were injected and separated on an ACE C18 HPLC column at a flow rate of 1.0 mL/min and column temperature of 40°C, by using the same gradient from the mobile phases of (A) 0.1% formic acid in water and (B) methanol as described for HPLC. The MS parameters were set as follows: electrospray ionization source (ESI) in a negative mode, nitrogen (N₂) as drying gas, flow rate at 8 L/min, gas temperature at 300°C, nebulizer at 40 psi, sheath gas temperature at 350°C, flow rate of sheath gas at 8 L/min, capillary voltage at 4.0 kV, end plate offset at -500 V, fragmentor at 150 V, skimmer at 65 V, Oct RF Vpp at 600 V, scan range of 100-1700 m/z, and collision energy at 25 V for MS and 45 V for MS/MS, respectively. The data was analyzed on Agilent MassHunter Qualitative Analysis B.06.00 and Agilent MassHunter Quantitative Analysis B.06.00 from Agilent Technologies (Santa Clara, CA, USA).

UPLC-MS/MS profiling was performed on Agilent 6,540 Ultra High Definition (UHD) Accurate-Mass Q-TOF LC/MS system from Agilent Technologies (Santa Clara, CA, United States). The samples (2 μL) were separated on a BEH C18 UPLC column at a flow rate of .4 mL/min, column temperature at 40°C, and with a gradient from solvents of .1% formic acid in water (A) and .1% formic acid in acetonitrile B) as follows: 2%–35% B at 0–10 min, 35%–75% B at 10–18 min, and 75%–100% B at 18–22.1 min. The MS instrument was configured as follows: electrospray ionization source (ESI) for both positive and negative modes, nitrogen (N2) as drying gas, flow rate at 8 L/min, gas temperature at 300°C, nebulizer at 40 psi, sheath gas temperature at 350°C, flow rate of sheath gas at 8 L/min, capillary voltage at 3.0 kV, end plate offset at −500 V, fragmentor at 150 V, skimmer at 65 V, Oct RF Vpp at 600 V, scan range of 100–1,700 m/z, and collision energy at 25 V for MS and 45 V for MS/MS, respectively. The data were analyzed with Agilent MassHunter Qualitative Analysis B.06.00 and Agilent MassHunter Quantitative Analysis B.06.00 from Agilent Technologies (Santa Clara, CA, United States).