2.2. Static headspace-gas chromatography (SH-GC) analysis
EOs were added to 10 mL of water or aqueous CD solutions
placed in 22 mL headspace glass vials. Vials were then sealed by
using a silicone septa and aluminum foil and thermostated at
25 ± 0.1 ◦C. After the equilibrium between aqueous and gaseous
phases had been established (30 min), 1 mL of vapor presents above
the solution was withdrawn from the vial by using a gas-tight
syringe and injected directly in the chromatographic column via
a transfer line (250 ◦C) for chromatographic analysis. All measurements
were conducted with an Agilent headspace autosampler and
a Perkin Elmer Autosystem XL equipped with a flame ionization
detector using a DB624 column gas chromatography. Temperature
conditions were as follows: initial temperature of 50 ◦C for 2 min,
increased to 190 ◦C at 2 ◦C/min giving a total runtime of 30 min.
Nitrogen was used as carrier vector. Main volatile components in
EOs were identified on the basis of gas chromatographic retention
times, determined by using standards of EOs components in the
same conditions.