More detailed description of MS Level parameter and algorithm
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.
</p><p>
- 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
+ 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 <i>MS Level</i> is detected,
+ the precursor m/z recorded in the MS2 scan is utilized to build a chromatogram feature.
+ </p><p>
+ The feature list of precursor signals is constructed using the specified <i>mass and
+ retention time tolerances</i>. 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.
</p><p>
If more than one peak is detected in the range or more precise peak integration
<dt>MS level</dt>
<dd>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. <i>Do not set MS Level in the
- Scan Selection field - this will cause the algorithm to behave improperly.</i></dd>
+ Scan Selection field - all MSn levels are required to trace MSn precursor origins.</i></dd>
<dt>m/z Tolerance</dt>
<dd>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.</dd>
