This article concerns laboratory research materials. It is not medical advice and does not provide instructions for human or veterinary use.
Match the document to the product
Compare the product name, lot or batch identifier, sample code, report date, and testing laboratory with the material being reviewed.
Identity and purity are different
Identity testing helps determine what substance is present. Purity estimates the proportion represented by the target material under the stated method.
Look at the analytical methods
COAs may reference methods such as high-performance liquid chromatography or mass spectrometry. Each method answers a particular question and has limitations.
Review quantity and other reported tests
Purity and quantity are not interchangeable. Sterility, endotoxin, residual solvents, and water content are separate tests and should not be assumed.
A practical COA checklist
Check the sample name, lot identifier, laboratory, report date, methods, identity, purity, analyzed quantity, verification features, and disclosures.
The key takeaway
A COA is evidence for the specific sample and tests shown—not an all-purpose guarantee. Avoid conclusions the report does not support.