What is a Certificate of Analysis?
A Certificate of Analysis (COA) is a quality assurance document issued by an analytical laboratory that confirms the identity, purity, and key specifications of a specific batch of a research compound. Each COA is specific to a single production batch and is the primary document used to verify that a compound meets the required quality standard before use in research.
Key Fields in a Peptide COA
Compound Identity
The compound name, common synonyms, and where applicable, the Chemical Abstracts Service (CAS) number. Verify this matches the compound you ordered.
Batch / Lot Number
A unique identifier for the specific production batch. This is the critical traceability link — the batch number on your vial label should match the batch number on the COA exactly. If they do not match, do not use the compound until the discrepancy is resolved.
Molecular Formula and Molecular Weight
The chemical formula and calculated molecular mass of the compound. These should match published reference values for the compound in question.
Purity (%)
The purity figure expressed as a percentage, derived from HPLC analysis. For research-grade compounds, a minimum of ≥98% is the accepted standard; Essential Peptides compounds are verified to ≥99% as standard. The analytical method used to determine purity should be stated (e.g. RP-HPLC at 214nm).
HPLC Method Details
Specifies the column type, mobile phase, gradient conditions, and detection wavelength used in the purity analysis. This allows the result to be independently verified if required.
Mass Spectrometry Result
The observed molecular ion mass recorded by MS analysis, compared against the theoretical mass. Confirmation that these values match (within stated tolerance) verifies sequence identity.
Storage Conditions
The recommended storage temperature and conditions for the compound. Follow these exactly — incorrect storage will void the analytical guarantee of the COA.
Issuing Laboratory
The name and accreditation details of the third-party analytical laboratory that performed the testing. A reputable COA will be issued by a named, identifiable laboratory — not by the supplier itself.
Release Date
The date on which the COA was issued. Verify this is consistent with the expected production and dispatch timeline for your order.
How to Cross-Reference Against Your Vial
On receipt of a compound, check the following against the COA before accepting into inventory:
- Batch number on vial label = batch number on COA
- Compound name on label = compound name on COA
- Quantity/mass matches order documentation
- Storage conditions on COA are being met immediately upon receipt
