UPLC-MS Analysis of Phytochemicals

Chromatographic analysis was performed using a Thermo Fisher Accela UPLC system (Thermo Fisher Scientific, San Jose, CA, United States) equipped with a quaternary pump solvent management system, an online degasser, a diode-array detector (DAD), a column compartment, and an auto-sampler using a Phenomenex UPLC Kinetex C18 column (2.1 × 100 mm, 1.7 μm). Chromatographic separation conditions were as follows: Flow rate: 0.2 ml/min; Injection volume: 3 μl; Column temperature: 25°C; Mobile phase A: an aqueous solution of 0.1% formic acid; Mobile phase B: acetonitrile; An elution gradient: 5%–25% B from 0–5 min, 25%–60% B from 5–28 min, 60%–90% B from 28–38 min and 90% B between 38–42 min; Detection wavelengths: 214, 254, and 280 nm. Mass spectrometry (MS) was performed using a Thermo Fisher Accela LTQ Orbitrap XL hybrid mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) equipped with an electrospray ionization (ESI) interface. The ESI source was set in positive ionization mode. MS acquisition was set with a scan range of 150–1300 m/z and a resolving power of 30,000 for full-scan (Fan et al., 2018 (link)).