Table 1. Gas chromatograph-mass spectrometer settings.
| Parameter | Setting | |
|---|---|---|
| Injector | ||
| Carrier gas | Helium | Hydrogen |
| Flow | 1.4 mL/min | 1.0 mL/min |
| Pressure | 9.4 psi | 1.5 psi |
| Injection mode | Splitless mode | |
| Injection volume | 1 μL | |
| Injector temperature | 250°C | |
| Oven temperature program | ||
| Initial ramp | 80°C at 6°C/min until reaching 120°C | |
| Final ramp | At 8°C/min until reaching 300°C for 29 min. | |
| Mass spectrometer | ||
| Ionization mode | Electron ionization | |
| Acquisition mode | Selected Ion Monitoring (SIM) | |
| Dwell time | 100 ms | |
| Source temperature | 230°C | |
| Quadrupole temperature | 150°C | |