Lab A used a 7890B Agilent GC with LECO Pegasus IV time-of-flight MS instrument (Leco, St. Josph/MI, USA). The column was 30 m long Restek 95% dimethyl/5% diphenyl polysiloxane RTX-5MS column, 0.25 mm internal diameter, 0.25 um film, and a 10 m empty guard column (Restek, Bellefonte, PA). The autosampler was a Gerstel automatic liner exchanger with a multi-purpose autosampler system and a cold injection system (ALEX MPS2/CIS) (GERSTEL, Mulheim an der Ruhr, Germany). Each sample was injected at 0.5 µL through the multi-baffled glass liners (Restek, Bellefont, PA) under splitless mode operation with a 25 s purge time, 40 ml/min purge flow, Helium carrier gas (5.0 grade), and a column carrier gas flow of 1 ml/min. The initial temperature of the injection liner was 50 °C, the equilibration time was 0.5 min, and the temperature increased 12 °C/second to 275 °C with a hold time of 3 min. The oven was initially set at 50 °C held for 30 s, and then ramped at rate of 20 °C/min to a final temperature 330 °C, with a hole time of 10 min.
The transfer line of the time of flight mass spectrometry (TOF–MS) was set at 280 °C, with a solvent delay of 5.6 min. The ion source temperature was 250 °C. Mass Spectra were collected from 85–500 Da at 70 eV electron ionization energy. The scan rate was maintained at 17 spectra per second.
The transfer line of the time of flight mass spectrometry (TOF–MS) was set at 280 °C, with a solvent delay of 5.6 min. The ion source temperature was 250 °C. Mass Spectra were collected from 85–500 Da at 70 eV electron ionization energy. The scan rate was maintained at 17 spectra per second.