A certificate of analysis (COA) is the testing laboratory's report on one specific lot of material. It applies to that lot only, not to the product in general.
What to check, section by section
- Laboratory. The name of the laboratory that ran the tests. An independent third-party laboratory has no stake in the result.
- Lot or batch number. This must match the lot number printed on your vial label. A certificate for a different lot tells you nothing about your vial.
- Sample identity. The compound name and, often, its expected molecular weight.
- Test date. When the analysis was done.
- Methods. Usually HPLC for purity and mass spectrometry (MS) for identity. Some certificates add a quantity (content) test, endotoxin or residual solvents.
- Results. The observed mass compared with the expected mass, the HPLC purity as a percentage of peak area, and a pass or fail against the specification.
- Chromatogram and spectrum. The raw traces behind the numbers. A clean main peak and a mass matching the expected value are what you want to see.
- Verification. Some laboratories print a code you can check on their website.
How we publish certificates
Every lot is sent for third-party testing. We publish the certificate on our Lab Results page when the lot is released, and the product page links to it. Until a document is attached, the product shows "COA pending" and no purity figure. Blends such as KLOW Blend show identity and quantity only, never a single purity percentage. Laboratory supplies do not carry a certificate.
Try it: an interactive certificate
Click each part of this sample layout to see what it means. It is a diagram, not a real certificate: values are shown as placeholders.
Select a part of the certificate.
Quick quiz
For laboratory research use only. This article describes chemistry and handling. It does not describe human use.