4.7.2. PCA of Extracts

The software MarkerlynxXS (Waters Corporation, Milford, MA, USA) was used to generate a matrix containing the *m*/*z* ratio of ions detected in each sample and the area under the curve of each peak in the chromatogram. PCA calculation was performed using Past 2.14 software (Waters Corporation). PC to be analyzed were selected according to the significance of the eigenvalues of each component. The loads were considered to evaluate the impact of the original variables on the new components, while percent of variance explained of the new PC selected were used to evaluate similarities and differences between the extracts studied.
