QUALITY & TESTING

Reading an HPLC Certificate of Analysis

Velox Peptides Research Team·Published May 2026·6 min read
For in vitro research use only. This guide is provided for scientific reference to help researchers interpret batch documentation. All Velox Peptides compounds are supplied for in vitro research use only.

What is a Certificate of Analysis?

A Certificate of Analysis (CoA) is the test report that comes with a research compound. It shows the results of the lab tests done on that exact batch (the specific group of vials made together). It is the main proof of what is really in the vial — what it is, how pure it is, and what form it takes. A real CoA should always be linked to a specific batch or lot number, not just to the product in general.

Every Velox Peptides compound is HPLC-tested by an outside lab (HPLC is a lab test that checks how pure something is), and the batch report is available on request. This guide explains how to read the main parts.

What HPLC purity actually means

HPLC (short for High-Performance Liquid Chromatography) is a lab test that splits a sample into its separate parts and measures how much of each part there is. On a CoA, “HPLC purity” tells you what percentage of the sample is the peptide you actually want. The rest is leftovers — small impurities, incomplete (truncated) peptide chains, or leftover chemicals from making it.

A number like “≥98% HPLC purity” means at least 98% of the material is the compound you want. The test also produces a chromatogram — a graph that shows peaks. It should have one big peak for your compound and only small peaks for everything else. A trustworthy CoA shows this graph, not just the number on its own.

Why mass spectrometry confirmation matters

HPLC tells you how much of the sample is one single compound, but not which compound it is. Mass spectrometry (MS) answers that. It is a lab test that weighs the peptide molecule (its molecular weight) and checks that the weight matches what the correct peptide should weigh.

A CoA that gives you both the HPLC purity and an MS-confirmed weight gives you two separate proofs: that the material is pure, and that it is the right molecule. Purity on its own, without checking the identity, is only half the story.

What to check on any CoA

Look for these things: a specific batch or lot number; the name of the lab that did the testing (ideally an outside, independent lab); the HPLC purity number with the chromatogram graph shown; an MS-confirmed molecular weight; what it looks like and its form (for example, white lyophilised, or freeze-dried, powder); and the date it was tested. Be careful with any report that has no batch number, names no lab, or shows a number with no graph behind it.

You can review Velox Peptides batch documentation in the CoA library, or read more about our testing process on the Quality & Testing page. New to ordering research peptides? See our guide to buying research peptides in the UK safely.

Frequently asked questions

What does HPLC purity mean on a CoA?
It is the percentage of the sample that is the target compound, as measured by High-Performance Liquid Chromatography. ≥98% means at least 98% of the material is the intended peptide.
Why does mass spectrometry matter?
HPLC shows how pure a sample is but not what it is. Mass spectrometry confirms the molecular weight matches the target sequence, verifying identity.
Should a CoA be batch-specific?
Yes. A genuine CoA reports results for a specific batch or lot number, not the product in general.
Where can I see Velox Peptides CoAs?
Batch documentation is available on request and archived in the CoA library. Every order includes a batch-specific certificate.
Compliance statement. Velox Peptides supplies research reagents for in vitro use by qualified researchers. Every compound is sold strictly as a research reagent. No product is a medicinal product within the meaning of the Human Medicines Regulations 2012. No product has been evaluated by the MHRA or FDA. No product is intended for human or veterinary consumption, diagnosis, treatment, cure, or prevention of any condition. Any use outside lawful scientific research is outside the scope of sale. See our Research Use Policy and MHRA Statement.

All research summaries on this page are derived from publicly available peer-reviewed literature. Velox Peptides makes no therapeutic claims. For research use only.