The programmed
oven temperature was: 130 C for 1 min, 130–170 C at
6.5 C/min, 170–215 C at 2.75C/min, 215 C for 12 min, 215–
230 C at 40 C/min, 230 C for 3 min. The carrier gas (H2) flow rate
was 1.7 mL/min; constant pressure mode was set up. The split ratio
was set at 50:1. The temperatures of injector and detector were 270
and 280 C, respectively. Peak areas were measured by using an Agilent
MSD Chemstation (version E.01.00.237) for HRGC-FID.