High-Performance Liquid Chromatography (HPLC) is the standard analytical method for measuring the purity of a research peptide. This guide explains how it works and how to interpret the result.
What HPLC measures
HPLC separates the components of a sample by passing it through a column under high pressure. Different molecules travel at different rates, producing distinct peaks that can be measured.
For a peptide, the main peak represents the target molecule; smaller peaks represent impurities or related substances. The relative size of the main peak gives the purity percentage.
Reading a purity figure
A purity figure such as 98% means the target peptide accounts for that proportion of the measured sample. Higher purity generally means fewer interfering substances in a research result.
Purity should always be read alongside an identity confirmation (commonly mass spectrometry), because purity alone does not prove the peak is the intended molecule.
Why third-party testing matters
Independent, third-party HPLC testing is performed outside the supplier, which removes any conflict of interest and gives researchers greater confidence in the reported figures.
Every Stratum product is third-party HPLC tested, with a Certificate of Analysis available on request. Our guide on the Certificate of Analysis explains how the full document fits together.
This guide is for general educational purposes only and describes laboratory research practice. Stratum products are supplied for laboratory research use only — not for human or animal consumption. See our research use disclaimer.