Reading the certificate of analysis

A CoA is a batch's identity document. What information it must contain, how to recognise a reliable certificate and how the QR code on the label links to it.

Updated 10/09/2026 · PURA LABS editorial

The Certificate of Analysis (CoA) summarises the test results of a single batch. It is not a marketing document but a measurement record. It should look correspondingly sober.

Mandatory items of a reliable CoA

  1. Product name and CAS number: unambiguous identification of the substance
  2. Batch or lot number: identical to the label
  3. Molecular formula and molar mass: the basis for the identity test
  4. Test method: e.g. RP-HPLC, ESI-MS, with method details
  5. Specification and result: side by side, so the assessment can be followed
  6. Raw data: chromatogram and mass spectrum as figures
  7. Testing laboratory, date and release: who measured and released it, and when

Warning signs

  • No lot number, or a number that is the same for all products
  • Only a percentage, no chromatogram
  • Purity without a stated method
  • Identity “conforms” without a measured mass
  • A date that precedes the batch’s manufacturing date

From label to report

Every PURA LABS label carries the lot number, along with a QR code. Both lead to the report for exactly that batch. You can also enter the number directly:

  • on the reports page in the “Check batch” field
  • or via the address puralabs-research.com/coa/YOUR-LOT-NUMBER

Reading a specification correctly

A specification such as “≥ 98.0 %” is the limit set before the measurement. The result must meet it. A result of 99.4 % against a specification of ≥ 98.0 % therefore conforms. What matters is that the specification is fixed in advance and not adjusted afterwards to match the result.

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