Start with identity.
Identity testing asks whether the submitted material is consistent with the compound named on the report. Methods such as liquid chromatography–mass spectrometry (LC-MS) compare analytical signals with the expected molecular characteristics.
Purity and net content answer different questions.
Chromatographic purity describes the relative proportion of the target material among detected components under the stated test conditions. Net content estimates how much target material was measured in the submitted vial. A high purity percentage does not, by itself, establish the amount in the container.
Match the report to the vial.
A useful COA should identify the laboratory, reported date, test methods, sample or lot identifier, and results. The lot printed on the vial should match the lot associated with the posted report.
- Confirm the product and lot
- Review the test method
- Separate purity from quantity
- Check the reporting laboratory and date
Know what a COA does not prove.
A COA reports the tests performed on the submitted sample. It does not establish suitability for human or veterinary use, and it should not be treated as a substitute for independent laboratory controls or a complete quality system.