Why is mass spectrometry needed on the COA?

HPLC measures purity, not identity. Mass spectrometry confirms the molecular weight and verifies that you have the correct compound.

What should I do if the COA batch number does not match my vial?

Contact the supplier immediately. The COA does not apply to your product. Reputable suppliers will provide the correct documentation or arrange a replacement. Do not use material without matched documentation.

Is third-party testing important?

Yes. Independent testing provides objective verification and removes potential conflicts of interest that can exist with in-house testing alone.

What is the minimum acceptable purity for research-grade peptides?

≥98% HPLC purity is the widely accepted industry standard. Many high-quality suppliers test to ≥99%.

Certificate of Analysis Archives

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Lab Guides

August 10, 2026 · zentralabs

How to Read a Certificate of Analysis (COA) for Research Peptides

A Certificate of Analysis (COA) is one of the most important documents in peptide research. It provides analytical data that…

Quality & Testing

August 7, 2026 · zentralabs

Understanding HPLC Purity: What the Percentage on Your Peptide COA Actually Means

A Certificate of Analysis rarely comes with much explanation attached to it. Researchers reviewing the document may encounter a purity…

Certificate of Analysis Articles

How to Read a Certificate of Analysis (COA) for Research Peptides

Understanding HPLC Purity: What the Percentage on Your Peptide COA Actually Means

Stay ahead of the research curve.