MSn feature list builder

Description

The MSn feature list builder detects MS1 precursor signals which possess an MSn scan. The modules scans the raw data looking for MSn scans and builds a chromatographic feature for each MS1 precursor ion with a corresponding MSn scan.

Precursor ion signals are detected through fragment scan tracing. Starting with all MS2 scans in range, MSn scans are recursively detected by tracing through each fragment scan associated with each previous MS level. If a scan at the specified MS Level is detected, the precursor m/z recorded in the MS2 scan is utilized to build a chromatogram feature.

The feature list of precursor signals is constructed using the specified mass and retention time tolerances. For each detected MSn-containing precursor signal, a targeted chromatogram in the retention time range is built using all MS1 basepeaks within the mass range.

If more than one peak is detected in the range or more precise peak integration is required, the feature list may be deconvoluted via the Chromatogram Deconvolution tool.

Method parameters

MS level
The MS level for precursor feature building. All fragment scans corresponding to this MS level are detected and traced back to their MS1 precursor ion origin. Do not set MS Level in the Scan Selection field - all MSn levels are required to trace MSn precursor origins.
m/z Tolerance
Precursor ion (MS1) mass tolerance for feature building. All MS1 base peaks within this mass range will be use to build a targeted chromatogram feature.
Retention time tolerance
Precursor ion (MS1) retention time tolerance for feature building. All MS1 base peaks with this retention time range will be used to build a targeted chromatogram feature.