HRMS Analysis of Medicinal Plant Extracts

For HRMS recording, the A. quinata A2 and A4 and C. ternatea C3 extracts (7 µL/band each) were applied in triplicate on two MS-grade HPTLC F₂₅₄ plates. The active zones of interest were eluted for 1 min with water−methanol (9:1, V/V) at a flow rate of 0.1 mL/min using the open-source modified auto-TLC-LC-MS interface [68 (link)]. The analytes were transferred through a 50-µL sample loop with an integrated desalting cartridge (Accucore RP-MS, 10 mm × 2.1 mm, 2.6 μm, Thermo Fisher Scientific) to the analytical HPLC column (Accucore RP-MS, 100 mm × 2.1 mm, 2.6 μm, Thermo Fisher Scientific) set to 40 °C. Solvent A (2.5 mM ammonium acetate in water, pH 4.5) and solvent B (methanol) were used at a flow rate of 0.4 mL/min for gradient elution, i.e., 0−2 min 2%B, 2−7 min increase to 100%B, hold, and 10−12 min decrease to 2%B. [61 (link)] The eluent was directed to the HESI-HRMS system (Q Exactive Plus, Thermo Fisher Scientific). The spectrometer parameters were as follows: capillary temperature 270 °C, spray voltage ± 3.5 kV, sheath gas 20 arbitrary units, aux gas 10 arbitrary units, S–Lens RF level 50. Full scan mass spectra m/z 100–1100 were recorded in the positive and negative ionization modes. The spectra were processed by Xcalibur 3.0.63 software (Thermo Fisher Scientific).