The oven temperature program was
initially set at 50 °C for 5 min, then raised up to 200 °C at a
rate of 2 °C/min, and finally held isothermal for 40 min. The
injectors were set at 240 °C, with a split ratio of 1/50 for FID
and 1/100 for MS. The FID detector was maintained at
250 °C. The carrier gas was helium He N60 at a flow rate of
1 mL/min. The injected liquid sample volume was equal to
0.1 μL (and some replicates were performed using 0.5 μL to
increase peak detectability) using a syringe from SGE.