Fig. 2 illustrates the applied workflow for the identification in the case of saluamine, a T P of furosemide. In step I an initially unknown peak with m/z of 248.970 and RT of 2.27 min was extracted. Based on its increasing abundance during the incubation (Fig. 2 a), the unknown peak passed step II. The mass spectrum(Fig. 2 b) shows a peak at m/z 250.972 with an abundance ratio of approximately 1:3 relative to m/z 248.970, which points to a 37 Cl is otopologue. In step III the base peak (i.e., m/z 248.970) was matched with a UM-PPS prediction as a TP from furosemide, with the molecular formula of C7H7ClN2O4S and the structure of saluamine. Finally, this was confirmed by UHPLC/QToF-MS analysis of as aluamine reference standard.