Extraction of Essential Oil
Prior to extraction, 10 mL of dichloromethane was added
into the receiving flask in order to decrease essential oil
loss. Pine nut shells (5 g) were subjected to steam
distillation for 3 h. The obtained essential oil was collected
in dichloromethane layer in the receiving flask. The extracts
passed through dewatering procedure over anhydrous
sodium sulfate, passed through a 0.45-μm filter, and stored
at 4 °C prior to GC-MS analysis.
GC-MS Analysis
GC-MS analysis was performed on an Agilent 7890A
gas chromatography instrument coupled with an Agilent
5975C Mass Spectrometer according to the analytical
method of a previous report (Zhang et al. 2009) with
slight modification. Briefly, the analytes were separated on