4.8.4. Biomarker Identification and Metabolic Pathway Analysis

The identities of the potential biomarkers were confirmed by comparing their mass spectra and chromatographic retention times with the available reference standards and a full spectral library containing MS/MS data obtained in the positive and/or negative ion modes. The Mass Fragment application manager (Waters MassLynx v4.1, Waters corp., Milford, CT, USA) was used to facilitate the MS/MS fragment ion analysis through the use of chemically intelligent peak-matching algorithms. This information was then used to search multiple databases and to analyze the potential metabolic

pathway using MetPA. Potential biological roles were evaluated by an enrichment analysis using MetaboAnalyst (version 3.0, McGill Univeristy, Montreal, Canada).
