Identifying the chemical features in untargeted datasets is a complex endeavor. Since several chemical formulas can have similar monoisotopic masses, especially for larger masses, at least the fragmentation spectra of the features (MS 2 ) are needed for a tentative compound identification. Data-dependent acquisition (DDA) is one of the main strategies to acquire MS 2 spectra. In this strategy, either a certain number of the most intense ions from the MS scan or ions with defined mass-to-charge ratio (m/z) are fragmented .