A certificate of analysis only means something if you can independently tie it to the vial in front of you. Here is the procedure a research lab can run in a few minutes, without taking the supplier's word for any of it.
1. Match the lot number on the vial to the COA
The single most common failure is a generic COA stapled to a different lot. The lot number printed on the vial must appear, character for character, on the certificate. If it doesn't, the document doesn't describe your material.
2. Confirm the issuing lab
A real COA names the third-party lab that ran the assay and carries that lab's own report ID. Pure North uses Janoshik Analytical; the report should resolve back to Janoshik, not to the supplier's own letterhead. A certificate with no independent lab named is a marketing sheet, not a COA.
3. Read the two numbers that matter
Purity (by HPLC) and identity (by mass spec) answer two different questions: how much of the sample is the target compound, and whether it is the right compound at all. A purity figure alone, with no identity confirmation, is incomplete, more in our HPLC vs LC-MS guide.
4. Cross-check against the public archive
Every lot Pure North has ever shipped has its COA archived publicly at /lab-results/. You can look up your lot there and confirm the document you received matches the archived original, a supplier that hides past lots can't offer that check.
5. Use the verification page
For a guided walk-through, /coa-verify/ steps through lot lookup and document matching. The published purity floor is 99.0%, with the catalog averaging 99.18%. Reference standards for laboratory research use only.