Guide · 1 min read · Updated October 6, 2026
What An HPLC Purity Figure Actually Means
The percentage on a report is a measurement with a method behind it. Know what it covers.
HPLC stands for high performance liquid chromatography. It separates a sample into its components and draws each one as a peak on a chart.
The Main Peak
The largest peak is the target compound. Smaller peaks are everything else the detector picked up.
Where The Percentage Comes From
Purity is usually the area of the main peak divided by the total area of all peaks. A higher figure means less of the sample was something else.
What It Does Not Tell You
- It does not confirm identity on its own. That is the job of mass spectrometry.
- It does not measure how much material is in the vial.
- It applies to the batch tested, not to other batches.
What To Ask For
The chromatogram itself, not only the number. A real report includes the trace.
Research use only. This guide explains how to verify a laboratory material. It is not usage, dosing or medical guidance.