When a research peptide is described as "≥99% pure", that figure almost always comes from High Performance Liquid Chromatography (HPLC). This article explains what HPLC measures and why it is the industry standard for peptide purity.
What HPLC does
HPLC separates the components of a sample as they pass through a column at different rates. A detector records each component as a peak. For a peptide, the target compound produces the main peak; impurities and by-products appear as additional, usually smaller, peaks.
How purity is calculated
Purity is expressed as the area of the main peak divided by the total area of all peaks, as a percentage. A result of 99% means the target peptide accounts for 99% of the detected material.
HPLC vs. mass spectrometry
- HPLC answers "how pure?" — the proportion of target compound.
- Mass spectrometry (MS) answers "is it the right molecule?" — confirming molecular weight and identity.
Together, HPLC and MS verify both purity and identity.
Why it matters for research
Impurities can confound experimental results. Verified high-purity material reduces variables and improves reproducibility. Every compound we supply is HPLC-tested to ≥99% purity and third-party verified.
For laboratory research use only — not for human or veterinary consumption.