High-Performance Liquid Chromatography (HPLC) is the standard way to assess peptide purity. It separates a sample into its components so the target peptide can be measured against any impurities, with the result given as a purity percentage.
A figure of "≥99% by HPLC" means the vial's contents are almost entirely the named peptide, with only trace synthesis by-products. Mass spectrometry is the companion technique: it confirms the molecular weight, and therefore the identity, of the compound.
Independent, third-party testing matters because it takes the supplier's own word out of the equation. A Certificate of Analysis (CoA) records the batch result and is the primary evidence a researcher should want before using any material.
Every Vosberg batch is independently HPLC-tested, with the CoA on request. Purity isn't a marketing number — it's the line between a usable reference material and an unknown.
This article is for educational and research-reference purposes only. It is not medical advice. All products are supplied strictly for in-vitro laboratory research use, not for human or veterinary consumption.
Reference: Research Peptide Purity & Testing — a full guide.