Untargeted Analysis
Untargeted mode discovers metabolite features from your RAW files without needing a metabolite list up front. LEAF detects every peak it can, aligns them across samples, and gives you a feature table to triage.
[Screenshot: Untargeted view showing feature table and EIC chart]
When to use it
| Use untargeted when... | Use targeted when... |
|---|---|
| You don't know what's in your sample | You have a defined panel of compounds to quantify |
| You're hunting for unknown metabolites | You're tracking specific pathways |
| You want a survey of one group vs another | You need quantitative comparisons of named compounds |
You can always run both: untargeted to find candidates, targeted to lock them in for routine analysis.
Switch to untargeted mode
On the Extract page, click the Targeted / Untargeted toggle at the top. The compound list editor disappears (you don't need a CSV) and the parameters sidebar swaps in untargeted-specific options.
Parameters
| Parameter | Default | What it does |
|---|---|---|
| Polarity | NEG | Match your method's polarity |
| Mass Tolerance | 5 ppm | Tighter than targeted — affects feature alignment |
| Min intensity | 1e5 | Drop features below this peak height |
| Min samples | 2 | Require a feature to appear in at least N samples to keep it |
| RT range | full run | Optionally restrict to a part of the run |
Run the extraction
Click Start Processing. Progress shows in the same floating action button as targeted runs. Untargeted runs typically take 2–5× longer than targeted because every peak has to be detected, not just the ones in your list.
Open the results
After completion, click Open in the jobs panel. The Untargeted view loads.
Layout
| Panel | What it shows |
|---|---|
| Feature table | Every detected feature with m/z, RT, detection rate, intensity stats |
| EIC chart | Chromatogram for the selected feature across samples |
| Alignment panel | RT alignment quality across samples |
| Gap-group panel | Features that should align but don't — flagged for review |
| Stats panel | Per-feature group comparisons (fold change, p-value) |
| Results panel | Filter, sort, and tag features for export |
Triage workflow
- Filter the feature table by detection rate (e.g., keep only features in >50% of samples)
- Sort by intensity or by group fold-change to find candidates
- Inspect the EIC chart — does the peak look real, or is it noise?
- Tag interesting features with flags or notes
- Export the tagged set as a CSV — feed it back into LEAF as a targeted CSV for routine quantification
Identify features
LEAF doesn't identify features for you — it gives you m/z and RT. To get a name, search:
- A spectral library (e.g., HMDB, METLIN, MoNA)
- An MS2 spectrum from the same sample (LEAF supports MS2 matching against mzVault libraries — see the LEAF developer docs)
- A pure standard run on the same instrument
When you have a name, add the feature to a targeted CSV for the next batch of samples.
Export
Untargeted exports save as .usd files — same format family as .msd, but with feature data instead of compound data. The export dialog also offers per-feature CSVs.
Next step
→ UI tour — every panel and button explained