GC-MS Analysis of Leaf Essential Oil

Chemical constituents in leaf essential oil and fraction E1 were analyzed using a Thermo Trace GC Ultra gas chromatograph equipped with a Polaris Q MSD mass spectrometer (Thermo Fisher Scientific, Austin, TX, USA). Analyte (1 μL) was injected into the capillary column (DB-5MS, Crossbond 5% phenyl methyl polysiloxane, 30 m length × 0.25 mm i.d. × 0.25 µm film thickness). The GC column temperature program was set as follows: initial temperature of 60 °C for 3 min; 2 °C/min up to 120 °C with a 3 min hold; 3 °C/min up to 180 °C; 10 °C/min up to 250 °C with a 5 min hold. The flow rate of the carrier gas, helium, was 1 mL/min and the split ratio was 1:10. The compound was characterized by comparing the mass spectra (m/z 50–650 amu) with library databases, including National Institute of Standards and Technology (NIST) and Wiley, and Arithmetic index (AI) [44 ]. The quantification of constituents was analyzed by integrating the peak area of the chromatogram [45 (link),46 (link)].