*2.4. Gas Chromatographic–Mass Spectral (GC–MS) Analysis*

Gas chromatography–mass spectrometry was carried out as previously described [14]: Shimadzu GCMS-QP2010 Ultra instrument, electron impact (EI) mode (electron energy = 70 eV), scan range = 40–400 atomic mass units, scan rate = 3.0 scans/s, and GC-MS solution software (Shimadzu Scientific Instruments, Columbia, MD, USA); ZB-5 fused silica capillary column, 30 m length, 0.25 mm internal diameter, 0.25 μm film thickness (Phenomenex, Torrance, CA, USA); He carrier gas, head pressure = 552 kPa, flow rate = 1.37 mL/min; injector temperature = 250 ◦C, ion source temperature = 200 ◦C, oven temperature program = 50 ◦C start, increased by 2 ◦C/min to 260 ◦C; 7% w/v solutions, 0.1 μL injections, split mode (30:1). Essential oil components were identified based on both their retention indices, which were determined by reference to a homologous *n*-alkane series, and their mass spectral fragmentation patterns available from the databases [17–20].
