How to Read a Certificate of Analysis (CoA)

A Certificate of Analysis (CoA) is a quality document issued by a testing laboratory that reports the analytical results for a specific batch of a compound. For research peptides and compounds, the CoA is the primary means by which a supplier demonstrates the quality and identity of their products. Understanding how to read and interpret a CoA is an essential skill for any researcher procuring peptides or research compounds.

This guide explains the key sections of a research peptide CoA and what to look for when assessing supplier documentation. All Bloom Vitality products are independently third-party tested, with batch-specific CoAs available on request via our Testing & Quality page.

Key Sections of a CoA

1. Product Identification

The CoA should clearly identify the compound tested, including:

• Compound name — Common name and/or IUPAC name
• CAS number — Chemical Abstracts Service registry number, providing an unambiguous chemical identifier
• Molecular formula and weight — Confirms the expected chemical composition
• Batch or lot number — Links the CoA to a specific production batch

2. Purity Result

Purity is typically expressed as a percentage and is one of the most important figures on a research peptide CoA. Common analytical methods used to determine purity include:

• HPLC (High-Performance Liquid Chromatography) — The gold standard for peptide purity determination. The peptide is separated chromatographically and quantified by UV absorbance. Results are expressed as area percentage — e.g. ≥98% purity by HPLC.
• MS (Mass Spectrometry) — Confirms the molecular identity of the compound by measuring mass-to-charge ratio. Often used alongside HPLC as an identity confirmation rather than a standalone purity method.

For research peptides, ≥98% purity by HPLC is generally considered acceptable for most research applications. Values below 95% warrant scrutiny.

3. Identity Confirmation

In addition to purity, a thorough CoA should confirm the identity of the compound tested. This is typically achieved via:

• Mass spectrometry (MS or LCMS) — Confirms that the measured molecular weight matches the expected value for the compound
• Amino acid analysis — For peptides, confirms the correct amino acid composition

4. Testing Laboratory Details

The issuing laboratory should be clearly identified. Key questions to consider:

• Is the laboratory independent of the supplier? (Third-party testing is more credible than in-house testing)
• Is the laboratory accredited (e.g. ISO 17025)? Accreditation provides assurance of analytical competence
• Is a verification reference provided? Some laboratories (including Janoshik, used by Bloom Vitality) provide online result verification

5. Test Date

Confirm the CoA is current and corresponds to the batch being supplied. A CoA from a different batch or a significantly earlier date does not provide assurance about the material you are receiving.

What is a Janoshik CoA?

Janoshik Analytical is an independent third-party testing laboratory that specialises in analysis of research compounds. Janoshik CoAs include a unique order reference that allows independent verification of results at verify.janoshik.com. This verification step allows researchers to confirm that the CoA document provided matches the result held on the laboratory’s own records — providing an additional layer of authenticity assurance.

Bloom Vitality uses Janoshik Analytical for independent batch testing. See our Testing & Quality page for further information and to request batch documentation.

Red Flags on a CoA

• No laboratory name or contact details
• No batch or lot number linking the CoA to a specific product
• Purity stated without specifying the analytical method
• In-house testing only (no independent third-party verification)
• No mass spectrometry identity confirmation
• Undated or very old test dates

For research and laboratory use only. This article is provided for informational purposes only and does not constitute analytical or regulatory advice.