A certificate of analysis (COA) is the document confirming exactly what a given batch of a product is and how pure it is. It is what separates a credible supplier from a random one.
The key elements of a certificate
- Compound name — the name, the CAS number (a unique identifier for the substance), the formula and the molecular mass
- Purity (tested by HPLC) — what percentage of the content is the declared compound; look for at least 98–99%. HPLC is a laboratory method for separating a sample and checking its composition
- Batch number (LOT) — it should match the number on the vial
- Test method — most often HPLC, sometimes also mass spectrometry (another method confirming what is in the sample)
- The date the test was performed
What to watch out for
A missing batch number, no information about the test method, or a “purity” stated without a specific percentage are warning signs. A proper certificate always refers to a specific batch (LOT), not to the product “in general”.
Certificates at SWISS LAB
We provide the certificate of analysis for the current batch on request — just give us the product name and the batch number (LOT) from the packaging.
