Rxi 5sil ms fused silica capillary column

The collected volatile fractions were injected in splitless mode into a 6890N Agilent GC (Agilent Technologies, Wilmington, NC, USA), which was equipped with a Rxi-5Sil MS fused-silica capillary column (30 m × 0.25 mm inner diameter × 0.25 μm, RESTEK, Bellefonte, PA, USA). Helium was used as carrier gas at a constant flow rate of 1.0 mL/min. The programmed GC oven temperature started at 55 °C for 3 min, then increased to 150 °C at the rate of 15 °C/min, then increased to 200 °C at the rate of 3 °C/min with a final hold at 200 °C for 2 min. The back inlet temperature was kept at 250 °C. The mass spectral analysis was done on time-of-flight mass spectrometer Pegasus III 4D TOF-MS (LECO, MI, USA). The mass spectral ionization energy was 70 eV with an ionization source temperature set on 200 °C. The MS scan range (m/z) was 29–500 amu with an acquisition rate of 30 spectra/s.

Gas Chromatography and Mass Spectrometry (GC-MS) was employed to identify the type of lipid-derived radicals detected by the ESR spectrometer. The Shimadzu (Kyoto, Japan) GC-MS QP2010 ultra system was equipped with a Shimadzu AOC-20i auto injector and Rxi-5Sil MS fused silica capillary column (30 m × 0.25 mm I.D., film thickness 0.25 μm, 5% phenyl/95% dimethylpolysiloxane, Restek, Bellefonte, PA, USA). Helium was used as the carrier gas at a flow rate of 1.0 mL/min, and the injector port temperature was 250 °C in split mode with a ratio of 1:10. The GC oven temperature was initially held at 35 °C for 5 min and then increased to 320 °C at a rate of 10 °C/min for 5 min. The mass spectrometer was operated in the electron impact (EI) ionization mode at an ion source temperature of 200 °C. The GC-MS interface temperature was maintained at 250 °C and the electron energy was kept at 70 eV.