COA
HPLC on a peptide COA
High-performance liquid chromatography, as usually reported on research-peptide certificates, is a separation with a UV detector. The headline purity figure is almost always the main peak’s share of total peak area.
What this tells you
- How much of the detected peak area, under this method and wavelength, belongs to the main peak.
- Whether the integration looks like a single dominant component or a crowded trace — if the chromatogram is attached.
What this does not tell you
- What the main peak is. That is an identity question.
- What fraction of the vial’s mass is peptide. Water and counterion are mostly invisible to this number.
- Endotoxin, sterility, residual solvents, or heavy metals.