Pegasus 3 4d tof ms

The samples were injected into an Agilent 6890N (Agilent Technologies, Wilmington, DE, USA) gas chromatograph equipped with a Rxi-5Sil MS column (30 m × 0.25 mmID × 0.25 μm; RESTEK, Bellefonte, PA, USA). We used the splitless injection mode and helium as a carrier gas at a constant flow rate of 1 mL/min. The GC temperature program was as follows: the initial column temperature 55 °C was maintained 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, and finally maintained at 200 °C for 2 min. The back-inlet temperature was kept at 250 °C. Mass spectral analysis was performed on a Pegasus III 4D TOF-MS (LECO, St. Joseph, MI, USA). The MS ionization energy (voltage) was set at 70 eV. The ionization source temperature was 200 °C; the MS scan range (m/z) was 29–500 amu; and the acquisition rate was 30 spectra/s.

The conditions for GC-TOF-MS analysis of VOCs were established following the previously reported methods, with some modifications [76 (link),77 (link)]. The collected volatile fractions were injected to an Agilent 6890N (Agilent Technologies, Wilmington, DE, USA) gas chromatograph using the split-less injection mode. The chromatographic column used was Rxi-5Sil MS (30 m × 0.25 mm ID × 0.25 μm; RESTEK, Bellefonte, PA, USA). As a carrier gas, helium (percentage purity > 99.999%) was used at a constant flow rate of 1 mL/min.
The temperature program was initially set at 55 °C for 3 min, then increased at 15 °C/min to 150 °C, then at 3 °C/min to 200 °C, and finally maintained at 200 °C for 2 min. The back-inlet temperature was held at 250 °C. A Pegasus III 4D TOF-MS (LECO, St. Joseph, MI, USA) was used to perform the mass spectral analysis. The TOFMS parameters were set as follows: MS ionization voltage at 70 eV, ionization source temperature at 200 °C, MS scan range (m/z) at 29–500 amu, and acquisition at 30 spectra/s rate.

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.