Precursors

For data-dependent acquisition (DDA), the Precursors tab maps each fragmented precursor ion as a point at its retention time × precursor m/z, across the included MS2 files. It is the quickest way to see what was selected for fragmentation and when.

DDA precursor-ion map

• Color by — File, Sample group, or none.
• Only files that contain MS2 spectra contribute; if none do, the view says so.

Moving between tabs

Click a precursor point to send its file, retention time and precursor m/z to the Spectrum tab; switch there to view the corresponding MS2 spectrum — and from that spectrum you can click fragment peaks straight into the EIC list.

Export

Save writes a static image of the precursor map.