How to Read a Certificate of Analysis

Knowledge Hub · COA basics

A practical checklist for matching a laboratory report to an identified research sample and understanding what its results do—and do not—establish.

Start with the identifying information

Match the named compound, labeled quantity, lot number, testing laboratory, accession or report number, and received and reported dates. If the lot on the material does not match the lot on the report, the certificate should not be treated as documentation for that item.

Read the method beside the result

A result has meaning only in the context of the stated analytical procedure. Identity, purity, and measured content answer different questions and may use different instruments, reference materials, calculations, and acceptance criteria.

Identity, purity, and net content are not interchangeable

Identity: Whether the detected analytical characteristics are consistent with the named compound under the stated method.

Purity: The proportion reported by the stated procedure. A purity result does not automatically describe sterility, endotoxin, residual solvent, or every possible impurity.

Net content: The measured amount in the submitted sample. It is distinct from identity and chromatographic purity.

Check the limitations

Laboratory results apply to the submitted sample and the scope of testing shown. A COA is not FDA approval, a prescription, a medical recommendation, a dosing guide, or proof of suitability for human or animal use.

Useful questions for a document review

  • Does the lot number match the labeled item?
  • Is the testing laboratory identified?
  • Are the analytical procedures named?
  • Are the result units and measured values clear?
  • Does the report distinguish identity, purity, and content?
  • Are any scope limitations or sample qualifications stated?

Research documentation education only. This guide is not medical, veterinary, legal, or regulatory advice and contains no human-use instructions.