A total of 6060 features were detected, of which 3742 had MS 2 data. To assess which features were potentially polyphenols, the 6060 features were matched by their monoisotopic mass with the PhytoHub database, one of the largest online databases on polyphenols containing currently 2268 analytes . To screen for additional exposome-related features, the features were matched by MS with the Exposome-Explorer database, which contains currently 1212 biomarkers for environmental exposure . Features that were MS 1 matched and had MS 2 data were then annotated by matching to several open and online spectral libraries, or by in silico fragmentation.