Db 5ms quartz capillary column

Volatile compounds were analyzed using a GC-MS system, equipped with a DB-5MS quartz capillary column (30 m × 0.25 mm × 0.25 µm, Shimadzu). The column oven temperature program was as follows: 40 °C for 2 min, increasing to 200 °C at a rate of 5 °C/min and holding for 6 min. Helium (99.999%) was used as the carrier gas at a flowrate of 1 mL/min. The ion source and quadrupole temperatures were 230 and 150 °C, respectively. The ionizing energy was 70 eV, and the mass range scanned was 40–500 amu in the full-scan acquisition mode.

The derivatized samples were separated on a nonpolar DB-5MS quartz capillary column (30 m × 0.25 mm × 0.25 μm; Shimadzu, Japan) of a GC-MS spectrometer (GC-MS-QP2010, Shimadzu, Japan) using the following parameters: sampling volume, 1 μL; carrier gas, helium (99.999%); flow rate, 1.0 mL·min⁻¹; and split ratio, 10 : 1. The initial oven temperature was 70°C maintained for 4 min and then increased to 110°C at the rate of 20°C·min⁻¹, 190°C at the rate of 8°C·min⁻¹, and 270°C at the rate of 8°C·min⁻¹ and maintained for 5 min. The inlet temperature was 280°C. The temperature of the electron impact ionization source was 200°C, the solvent delay time was 6.5 min, and the scanning range of mass spectrometry was 35–550 m/z. During the formal analysis, the sampling sequence of all samples was randomly arranged to avoid the run order effect and systematic variation attributed to instrument-based analyses. One QC sample was analyzed after every five sample injections.