Comet parameter: precursor_NL_ions

  • Controls whether or not precursor neutral loss peaks are considered in the xcorr scoring.
  • If left blank, this parameter is ignored.
  • To consider precursor neutral loss peaks, add one or more neutral loss mass value separated by a space.
  • Each entered mass value will be subtracted from the experimentral precursor mass and resulting neutral loss m/z values for all charge states (from 1 to precursor charge) will be analyzed.
  • As these neutral loss peaks are analyzed along side fragment ion peaks, the fragment tolerance settings (fragment_bin_tol, fragment_bin_offset, theoretical_fragment_ion) apply to the precursor neutral loss peaks.
  • The default value is blank/unused if this parameter is missing.

Example:
precursor_NL_ions =                                     ... entry blank; unused
precursor_NL_ions = 79.96633 97.97689