**2.5 Gas chromatography coupled to mass spectrometry analyses (GC/MS)**

GC/MS analyses were performed using a chromatograph Shimadzu 2010 Plus system coupled with a Shimadzu QP-2010 Plus selective detector (MSD) and equipped with a DB5-MS capillary fused silica column (60 m, 0.25 mm I.D., 0.25 μm film thickness). The oven temperature program initiated at 60°C, then was raised by 3°C/min to 246°C, and then was held for 20 min. Other operating conditions were as follows: carrier gas, He (99.999%), with a flow rate of 1.03 mL/min; injector temperature, 220°C; split ratio of 1:50; and injection volume of 1 μL. Mass spectra were taken at 70 eV. The m/z values were recorded in the range of m/z 40–700 Da.
