What a COA is
A Certificate of Analysis is a batch-specific summary of tests performed on a material. Its value depends on traceability, test methods, acceptance criteria, laboratory competence, and whether the tested sample can be linked to the supplied batch.
Identity versus purity
Identity asks whether the material is what it claims to be. Purity estimates the proportion represented by a target signal under a specified method. A high chromatographic purity percentage does not independently prove identity, concentration, sterility, or absence of every contaminant.
Common analytical methods
High-performance liquid chromatography can separate components and estimate chromatographic purity. Mass spectrometry can support molecular identity. Other attributes may require separate methods, including water content, residual solvents, peptide content, bioburden, endotoxin, or sterility testing.
Traceability checks
Look for a batch or lot number, sample identifier, test date, method description, result units, laboratory identity, and a clear connection between the report and the supplied material. Screenshots without traceable identifiers provide limited assurance.
Independent testing
Third-party testing can reduce conflicts of interest, but independence alone does not guarantee quality. Method suitability, sample custody, accreditation scope, and transparent reporting remain important.
Further reading and source verification
These links are provided so readers can review scientific or regulatory sources directly. External content may address clinical or experimental procedures that fall outside this library’s editorial scope.