A COA proves something only when it points to your vial. Here is how to tell a lot-matched certificate from a decorative PDF.
A Certificate of Analysis is the most important document a peptide vendor gives you. It is also the easiest document to fake. Four checks separate a real certificate from a decorative one.
1 — Find your lot number on the certificate. The vial carries a lot number. The certificate must carry the same one. A certificate without your lot number describes a different batch, or no batch at all.
2 — Find the name of the laboratory. Look for a named laboratory with ISO 17025 accreditation. ISO 17025 sets the requirements for testing laboratory competence. An in-house result carries no independent check.
3 — Read the method, not the headline. The certificate must show the HPLC result and the mass spectrometry result. HPLC separates the target compound from its impurities and gives the purity figure. Mass spectrometry confirms the molecular weight and the identity. A purity percentage without a method is a claim.
4 — Look for the chromatogram and the date. The chromatogram shows the peaks behind the purity figure. The test date tells you how old the result is.
Then cross-check. Open the vendor's public COA archive. Search for your lot number. If the archive has no entry for your lot, the certificate stands alone and you cannot verify it.
Annotated certificate
An annotated image of a real, published COA belongs here — with the lot number, the laboratory name, the method fields, the chromatogram and the date marked. One real annotated certificate is worth more than a page of stock photography. Add it once a redacted certificate is ready to host.
Sources
- ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories.ISO/IEC 17025:2017View source →
- FDA — Bulk Drug Substances Used in Compounding Under Section 503A (requires a valid certificate of analysis).View source →
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