Gas chromatography-mass spectrometry

The plant extract was analysed in a single quadrupole GC-MS system (Thermo Scientific TRACE™ 1300 ISQ™ LT). Solution of the extract was prepared in acetonitrile (50 mg in 3 mL). As a stationary phase, a non-polar column TR-5MS (260F142P, 30 m × 0.25 mm × 0.25 µm with film thickness of 0.25 μm) was used. The injector port and oven temperature were set 250 °C. Helium was used as a carrier gas, and was released into the oven chamber at a constant flow rate of 1 mL/min. Sample was injected in a volume of 1 μL in split mode at the splitting ratio 1:50. The mass spectrometer was run with an ionization electron energy of 70 eV. Ion source and transfer line temperature were set at 250 °C. The total running duration was 55 min. The final chromatogram was generated with Thermo Scientific™ Xcalibur™ software. Compounds were identified based on their retention time, chemical formula and molecular weight from libraries of Wiley Registry™ and National Institute of Standards and Technology database.