How to Read a Certificate of Analysis
A practical guide to interpreting each section of a Certificate of Analysis for research compounds.
Overview
A Certificate of Analysis (CoA) is a laboratory document that reports the test results for a specific batch of a compound. It is the primary evidence of identity, purity, and quality.
Batch Information
A CoA should identify the product, batch number, lot number, manufacture date, and the testing laboratory. Cross-reference these with the label on your material.
Testing Methods
Typical tests include:
- Identity — confirmed by mass spectrometry (MS) or HPLC retention time.
- Purity — quantified by HPLC area percent.
- Residual solvents — by gas chromatography (GC).
- Water content — by Karl Fischer titration or loss on drying.
- Appearance — visual description.
Reading a CoA
For each test, locate the result, the specification, and the pass/fail status. A conforming batch shows every result within its specification.
Acceptance Criteria
Specifications define the acceptable range. A result marked "Conforms" or "Pass" meets the specification; "Non-conforms" or "Fail" does not.
Verification
You can verify a CoA by contacting the issuing laboratory and quoting the batch and lot numbers. Independent (third-party) testing provides the strongest assurance.
Research Use Notice: This material is provided for educational and laboratory research purposes only. It is not intended for human or veterinary use, diagnosis, or treatment. Always follow your institution's safety and handling protocols.
This article is for laboratory research and educational purposes only. It makes no medical, therapeutic, or diagnostic claims.
Research Use Only. This content is provided for educational and laboratory research purposes only. It is not intended for human or veterinary use, diagnosis, or treatment, and makes no medical or therapeutic claims.
