2.4. Gas chromatography-mass spectrometry GC-MS analyses
The essential oils were analysed on a Shimadzu gas chromatograph Model GC2010 coupled to
a Shimadzu MS model QP2010, equipped with a DB5 MS column (30m X 0.25mm; 0.25μm),
programming from 50°C (5 min) to 300°C at 5°C/min, 5 min hold. Helium was used as carrier gas (1.0
mL/min): injection in split mode (1:30); injector and detector temperatures were 250°C and 280°C
respectively. The MS working in electron impact mode at 70 eV; electron multiplier, 2500 V; ion
source Temperature, 180°C; mass spectra data were acquired in the scan mode in m/z range 33-450.