2.3 | Gas Chromatography-Mass Spectrometry (GS-MS) data
extraction
The dried hair extracts were resuspended in 200 μL of sodium hydroxide
(1 M) and chemically derivatized via the methyl chloroformate method
based on previous recommendations.17 All samples were
analyzed in a single batch, and derivatized compounds were separated by
a GC7890 chromatography system coupled to an MSD5975 with electron
impact ionization (70 eV) (Agilent, California, USA). The automated Mass
Spectral Deconvolution and Identification System software was utilized
for metabolite deconvolution. Subsequently, the metabolite
identifications, GS-MS data mining, and data normalization were
performed as previously described.17