*3.9. GC-FID and GC-MS Analysis*

A total of 1 µL of the obtained extracts of volatiles was analyzed by GC–FID using an Agilent gas chromatograph 6890N fitted with an HP-5MS column (30 m × 250 µm × 0.5 µm) in splitless mode. Detector and injector temperatures were set to 250 ◦C. The following oven temperature program was used: 50 ◦C for 2 min, heating from 50 to 320 ◦C at a rate of 5 K min−<sup>1</sup> . The final temperature was held for 6 min. Hydrogen was used as carrier gas with a constant flow rate of 1.2 mL min−<sup>1</sup> . GC-MS was performed using an Agilent mass spectrometer 5975B, on an HP-5MS column (see GC), operating at 70 eV ionization energy, using the same temperature program as above. Helium was used as carrier gas with a constant flow rate of 1.2 mL min−<sup>1</sup> . Retention indices were calculated by using retention times of C6-C24-alkanes that were injected under the same chromatographic conditions.
