in many spectroscopic softwares, we considered the treated spectra
(before decomposition) as variables in Principal Component Analyses
(PCA). As a second approach, the fitting parameters (band positions
P, full width at half maximum W, area A, and profile K) were
considered as variables in PCA. All the PCA score plots are presented
on the two first principal components (PC); the following PCs do not
show a more significant separation between the different items. More
detailed explanations are presented within the results part (3.2 and
3.3 paragraphs).