What a COA documents
A well-formed COA identifies the compound tested, the batch or lot it references, the analytical methods used (typically HPLC and mass spectrometry), the measured purity, and the date of analysis. It should also identify the laboratory that performed the testing and be signed or otherwise attributable to a named analyst.
Batch-specific vs. representative COAs
Batch-specific COAs correspond to the exact lot a buyer receives. Representative COAs describe a prior production run and only imply — rather than prove — the current batch's quality. Research programs that require reproducibility should insist on batch-specific documentation.
Reading purity numbers
Purity is typically reported as an area-percent from an HPLC chromatogram. Values above 98% are common for reputable suppliers, but the number alone is not enough: the chromatogram itself, the injection volume, and the identity-confirming mass spectrum should also be published so the result can be independently interpreted.
Red flags
Watch for COAs with no lab name, no analyst signature, mismatched compound names, missing chromatograms, or dates that predate the batch's manufacture. Reused COAs across many lots are also a warning sign.
How Kyzen One uses COAs
Our review team assesses whether a supplier publishes COAs publicly, whether those COAs are batch-specific, and whether an independent third-party laboratory is named. Suppliers that publish complete, batch-level documentation earn stronger transparency signals in our comparisons.