An Agilent gas chromatography–mass spectrometer (Agilent 6890
N/5973I) coupled with electrospray ionization was used for the phytochemical
analysis. Helium gas with a flow rate of 1.2 mL/min was used
as a carrier, and 1 μL of sample dissolved in ethanolwas injected for analysis.
A single quadrupole detector was used for the separation of various
phytochemicals using an HP-5 MS capillary column (0.25 mm ×
30 m × 0.25 μm film thickness). The oven temperature was initially
maintained at 70 °C for 2 min and then gradually increased at the rate
of 20 °C/min to 305 °C for 30 min with a 1-minute hold at each point.
The mass spectrometer electrospray ion source operated at 70 eV, and
the acquisition range was between 35 m/z and 700 m/z, with a scan
rate of 1 scan/s. Mass spectral correlations were performed using the
NIST02 database.