GC analysis was carried out using an Agilent 6850 gas chromatograph,
under the following operation conditions: vector gas,
Helium; injector and detector temperatures, 250 C; injected volume,
1 l; split ration 1/100; HP1 column (J&W Scientific), polydimethylsiloxane
(10 m 1 mm i.d., film thickness 0.4 m;
constant flow 0.3 mL/min). Te