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MSn tree feature list builder

Feature detection → MSn → MSn tree feature list builder

This module is an alternative to the Chromatogram builder for creating chromatograms based on MS2 spectra or MSn trees.

  1. Groups all MS2 spectra are by an m/z tolerance.
  2. Adds MSn, multi-stage fragmentation, spectra to the MS2 groups, if they are present.
  3. Builds an extracted ion chromatogram (EIC) for each group around their first MS2 scans precursor m/z and the m/z tolerance.
  4. The EICs may be empty if the precursor m/z reported in the MS2 scan metadata does not match the MS1 data or if the m/z tolerance is too narrow.
  5. Even empty EICs will be reported in the resulting feature list with their respective precursor m/z and fragmentation scans.

Parameters

Raw data files

The selected data files to process.

EIC scans

A filter to select scans (usually MS1) for building extracted ion chromatograms.

m/z tolerance (scan-to-scan)

Defines the fluctuation of an individual m/z peak in between scans. For TOF instruments, 0.005 m/z or 20 ppm is a good starting point, while Orbitraps or FT-ICRs can achieve narrower signals depending on the set mass resolution.

Suffix

This suffix is added to the produced feature list.


Robin Schmid