A certificate of analysis, or COA, records tests and results for a stated batch. It should be read alongside the agreed purchasing specification. A sample COA demonstrates a document format; it does not certify a batch that has not yet been manufactured or allocated.
Fields to match
Check the product identity, batch or lot number, report date, test method, acceptance criteria and actual results. Ask how identity was confirmed and whether chromatographic purity is reported by area percentage or another method. The method and calculation matter when comparing figures between suppliers.
Questions worth asking
- Does the COA match the material and packaging being quoted?
- Are tests performed for each batch or by another defined sampling plan?
- Is supporting chromatographic or mass data available for review?
- How are deviations or out-of-specification results handled?
Where a product has special storage or shipping needs, check that the record reflects those conditions. A COA is one part of an assessment; safety data, traceability and destination-market requirements may also matter. Read our documentation approach.