Use the Nearby Precursor marker to mark the peaks in the current MS (n-1) scan that the instrument selected for data-dependent MSn acquisition in the current scan or another scan. The application searches for matching data-dependent scans (by the precursor ion’s m/z value within the specified mass tolerance) within the specified time range of the current scan. You can change the default behavior (that is, Entire File) for this marker on the Display Options dialog box.

Procedure

  1. Open an injection or a raw data file (see Open injections or raw data files).
  2. The Chromatogram view and Spectrum view open.
  3. Select the Spectrum view.
  4. Select the Ellipsis menu to open the Display Options dialog box.
  5. In the Labels area, select the Nearby Precursors checkbox.
  6. Enables the Nearby precursor time range box.
  7. In the Nearby Precursor area, do one of the following to specify the search for the data-dependent scans:
  8. Set the search to every scan in the file (by default, Entire File is selected)
  9. Set the time range to search within the raw data file.

  11. NOTE

    Consider the experiment type when setting the time range. For infusion experiments, consider setting the search range to the entire file. For chromatography experiments, consider basing the search range on the chromatographic peak width.

  12. Select OK to apply the labels to the active spectrum.