Lcquan quantitation software

The LC–MS system was a Thermo TSQ Quantum Ultra triple-quadrupole mass spectrometer equipped with an electrospray ionization source (San Jose, CA, USA). LCquan quantitation software (version 2.5.6, Thermo Fisher Scientific, Waltham, MA, USA) was used to control the LC–MS system for data acquisition and analysis. Chromatographic separation was conducted using a Waters XTerra^® MS C18 column (3.0 mm × 50 mm, 5 µm) maintained at 20 °C. By injecting 5 µL samples with flow rate of 0.2 mL/min, chromatographic separation was achieved using a mobile phase of 0.1% formic acid water (A) and acetonitrile (B) via gradient elution, 0–2 min, 20% B; 2–3 min, 30% B; 3–20 min, 30% B. The analytes were detected in ESI source with positive and negative ion modes in individual runs with multiple reaction monitoring.

Chromatographic separation was performed on a Shimadzu HPLC system (Kyoto, Japan) using a Thermo Syncronis-C₁₈ column (50 mm × 2.1 mm, 5 μm) at 20 °C. The mobile phase of 0.05% formic acid (A) and methanol (B) was formed via gradient elution. The program was performed as follows: 0–0.5 min, 80% A; 1.0–5.0 min, 70% A; 5.5–10.0 min, 80% A. The flow rate was kept at 0.2 mL/min. The sample injection volume was 5 μL.
MS/MS analyses were performed using a Thermo TSQ Quantum Ultra triple-quadrupole mass spectrometer equipped with an electrospray ionization source (San Jose, CA, USA). The analytes were detected in positive SRM mode with an electrospray voltage of 4.2 kV and a capillary temperature of 370 °C. Nitrogen was used as the sheath gas (30 Arb) as well as the auxiliary gas (10 Arb), and argon was used as the collision gas (1.0 m Torr). LCquan quantitation software (version 2.5.6, ThermoFisher Scientific, Waltham, MA, USA) was used for data acquisition and analysis.