Fig. 1.

General procedure of feature finding. A, starting with the most intense peaks (magenta dots), potential mass traces are extended with peaks compatible in m/z back and forth in retention time. B, each mass trace is smoothed to facilitate the determination of chromatographic maxima. Multimodal elution profiles are split into smaller mass traces with respect to the number of maxima. C, based on this set of mass traces, potential feature hypotheses are generated and scored according to their compatibility with theoretical isotope patterns. D, finally, the best-scoring hypotheses are assembled to features.