Figure 2.

Distribution MS² spectra acquired by DDA (A), i-DDA (B), xcms-DDA (C) and hmdb-DDA (D) assigned to informative (blue) and noise (grey) LC–MS features. Note: DDA: untargeted selection of precursors in the 70–1500 Da range; i-DDA: untargeted iterated DDA, in which MS² spectra were acquired in seven QC replicates using DDA in the [70–200], [200–400], [40–600], [600–800], [800–1000], [1000–1250], and [1250–1500] Da ranges; xcms-DDA: targeted dynamic iterated DDA, in which precursor ions were selected using an inclusion list generated from the cleaned-up peak table obtained after the injection of two blanks and three QCs during system conditioning; hmdb-DDA: targeted dynamic iterated DDA using an inclusion list of (pre)annotated features in the cleaned-up peak table obtained after the injection of two blanks and three QCs during system conditioning.