A total of 1.0 µL of the sample solution was used in a Shimadzu GC-2010 gas chromatograph (Shimadzu Scientific Instrument, Inc., Columbia, MD, USA).
The GC-MS system was equipped with an HP-5ms (30 m × 250 µm × 0.25 µm) chromatographic column, made of (5%-phenyl)-methylpolysiloxane.
In the heating procedure, the initial temperature was set at 40 °C for 2 min, increased at 5 °C/min to 230 °C and held at 230 °C for 2 min, then increased to 250 °C at 20 °C/min and held at 250 °C for another 2 min. Samples were injected in splitless mode; Injection time was 1.00 min. The carrier gas was helium with a flow rate of one mL/min. The temperature of the GC injector was 250 °C.
The GC MS-QP2010 SE mass spectrometer was operated in EI mode at 70 eV of electron energy; ion source temperature was equal to 230 °C, and the interface temperature was equal to 250 °C. The solvent delay time was 1.00 min; The scan interval was 0.30 s with a 2,000 amu/s scan speed, and the scan Mas range was 50∼550 m/z. The maximum length of retention time was 43.00 min. All measurements were repeated three times.
The GC-MS system was equipped with an HP-5ms (30 m × 250 µm × 0.25 µm) chromatographic column, made of (5%-phenyl)-methylpolysiloxane.
In the heating procedure, the initial temperature was set at 40 °C for 2 min, increased at 5 °C/min to 230 °C and held at 230 °C for 2 min, then increased to 250 °C at 20 °C/min and held at 250 °C for another 2 min. Samples were injected in splitless mode; Injection time was 1.00 min. The carrier gas was helium with a flow rate of one mL/min. The temperature of the GC injector was 250 °C.
The GC MS-QP2010 SE mass spectrometer was operated in EI mode at 70 eV of electron energy; ion source temperature was equal to 230 °C, and the interface temperature was equal to 250 °C. The solvent delay time was 1.00 min; The scan interval was 0.30 s with a 2,000 amu/s scan speed, and the scan Mas range was 50∼550 m/z. The maximum length of retention time was 43.00 min. All measurements were repeated three times.