Fig. 2 illustrates the applied workflow for the identification in the case of saluamine, a TP of furosemide. In step I an ini-tially unknown peak with m/z of 248.970 and RT of 2.27 min wasextracted. Based on its increasing abundance during the incuba-tion (Fig. 2a), the unknown peak passed step II. The mass spectrum(Fig. 2b) shows a peak at m/z 250.972 with an abundance ratioof approximately 1:3 relative to m/z 248.970, which points to a37Cl isotopologue. In step III the base peak (i.e., m/z 248.970) wasmatched with a UM-PPS prediction as a TP from furosemide, withthe molecular formula of C7H7ClN2O4S and the structure of salu-amine. Finally, this was confirmed by UHPLC/QToF-MS analysis ofa saluamine reference standard.