GC-MS Analysis of TMS-Derivatized Metabolites

The manual TMS derivatisation was performed following the protocol published in Pinu et al. [21 (link)] and the derivatised samples were injected into an Agilent GC 7890 coupled to a MSD 5975 (Agilent Technologies, Santa Clara, CA, USA) with a quadrupole mass selective detector (Electron Ionisation) operated at 70 eV. The column used for the analysis of TMS-derivatized samples was a Zebron ZB-1701 (Phenomenex, Torrance, CA, USA), 30 m × 250 µm (internal diameter) × 0.15 µm (film thickness), with a 5-m guard column. The MS was operated in scan mode, where scanning started after 5 min (mass range 40 to 650 atomic mass unit (a.m.u ) at 1.47 scans/s). GC-MS parameters are already described in Villas-Boas et al [18 (link)].