Fig. 2

Schema of the workflow for data processing and peak annotation to obtain the data matrix. Non-processed data for GC-TOF–MS analysis of each sample were exported as NetCDF files. These files were imported in MATLAB for baseline correction, peak alignment, and deconvolution by the H-MCR method. Libraries were prepared for the provisional identification of the extracted mass spectra of the VOC peaks (gray box). After merging the information into a data matrix, we obtained a data matrix comprised of the compound name, sample name, and the sum of the peak area of each extracted mass