GC-MS analysis
The essential oils from aerial parts of A. capitatum and L.
aromatica were analyzed by GC-MS electron impact ionization
(EI) method on GC-17A gas chromatograph
(Shimadzu) coupled to a GC-MS QP 5050A Mass
Spectrometer (Shimadzu); fused silica capillary column
(30m x 2.5mm; 0.25m film thickness), coated with DB-5
(J&W); column temperature 100oC (2 min) to 250oC at the
rate of 3oC/min; carrier gas, helium at constant pressure of
90Kpa. Acquisition parameters full scan; scan range 40-350
amu. 2 μl of the diluted samples (1ml oil in 50 ml solvent)
were injected.