Independent guide to data evaluation in UNICORN™

Integrate detector response, map fractions, and preserve a defensible evaluation record.

Independent educational guide by ChromatoHub. Not affiliated with, sponsored by, or endorsed by Cytiva™. ÄKTA™ and UNICORN™ are trademarks of Cytiva™ or its affiliates. Trademark information.

Opening and viewing a result

Open the result and inspect the recorded method, system settings, run log, detector channels, and fraction information before evaluating it. UNICORN™ workflows, licenses, databases, export options, and labels vary by release and configuration; use the manual and on-screen help for the installed version rather than assuming a universal menu path.

Peak integration

Define and record the integration interval and baseline for each reported feature. Do not impose one run-wide baseline prescription: a baseline should be appropriate to the stated region and question. Key outputs include:

  • Retention volume (VR) — peak maximum in mL.
  • Integrated detector response — area above the selected baseline, with its signal × time or volume units.
  • Peak width at half maximum (w½) — used to calculate plate count.
  • Area % — relative integrated response within the explicitly stated set of regions.

Area % is not purity, mass, recovery, concentration, or identity. Detector response and integration are method-dependent; quantitative interpretation requires an appropriate validated calibration/response model. Use an orthogonal assay when a purity or identity decision is required.

Fraction analysis table

Record fraction/tube identifiers, collector start/end, detector-mapped start/end, and the delay basis. A collector is downstream of the detector, so map a detector feature to its physical fractions using the calibrated detector-to-collector delay. Pooling may be guided by the trace and stated criteria, but needs appropriate assay evidence; a central-looking fraction set is not automatically purer.

Chromatogram with UV, conductivity and %B, injection mark and delay-mapped fractionsA UV trace shows a small flow-through peak after the injection mark and a main peak during the gradient. The conductivity trace rises later than the programmed %B line. Two rows of fraction marks sit below the axis: tube boundaries as recorded at the collector, and the same tubes shifted earlier by the delay volume so they line up with the detector trace.010203040050100Volume at UV monitor (mL)UV signal (relative)%B programmedInjectUVconductivity (mS/cm, rescaled)%B programmedTube changes at collectorSame tubes on UV trace (collector volume − delay)123456← delay (exaggerated)
Schematic evaluation view (illustrative data). UV absorbance, conductivity and the programmed %B share one volume axis; conductivity trails the programmed gradient because the new buffer must first pass the mixer and column. The collector changes tubes at the volumes in the upper row, but the liquid entering a tube passed the UV monitor one delay volume earlier, so each tube maps back onto the chromatogram as in the lower row. The offset is exaggerated; use the calibrated delay for your own system and tubing. Delay mapping: Agilent OpenLab Delay Calibration documentation (delay volume is the tubing volume from detector to collector; recalibrate after tubing changes) and Cytiva™ ÄKTA™ pure data file (both read 2026-09-25).

Exporting a reproducible record

Export or retain the original result, detector data, integration settings, baseline definition, fraction map, delay calibration basis, and report metadata in the formats available in your installation. Verify exported values against the source result before relying on them downstream.

Sources and scope

Agilent OpenLab: Peak area measurement (official documentation, accessed 2026-09-25) defines area for a simple isolated peak as accumulated signal above the baseline between start and stop. Agilent OpenLab: Delay Calibration (official documentation, accessed 2026-09-25) supports detector-to-collector delay mapping. The supplied Cytiva™ UNICORN™ Evaluation Manual was read at this URL on 2026-09-25 and identifies itself as UNICORN™ 7.4; it supports version-scoped evaluation/reporting features, not universal UI instructions. If the direct manual link is unavailable, use Cytiva™’s official documentation finder and select the matching software version and instrument.

Try it on a trace

Open a two-column chromatogram in the workbench, or load the synthetic example. No account needed.

Open the workbench

Send feedback

What is it about?

At least 5 characters.0 / 4000

So we can reply. Leave it empty to stay anonymous.

Page: /learn/akta/evaluation