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Table 1 Quality control checks within the prescreening workflow applied to the MS1 and MS2 spectral data for each case

From: Retrospective non-target analysis to support regulatory water monitoring: from masses of interest to recommendations via in silico workflows

Quality control check Description Positive mode threshold Negative mode threshold
1 Availability of MS1 precursor Presence/absence
2 Minimum MS1 intensity 1 × 105 1 × 104
3 Maximum MS1 noise level 3x (average baseline intensity)
4 Availability of MS2 corresponding to MS1 precursor Presence/absence
5 MS1–MS2 alignment window 0.3 min (i.e. ± 0.15 min)
6 Deduplication of cases Highest MS1 intensity
7 Minimum peak width and overall shape (manual QC) 0.1 min
  1. Thresholds apply to data measured using an Orbitrap instrument. Checks 1–5 are part of the automated prescreening workflow, while checks 6–7 were performed manually