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Understanding Certificates of Analysis

A plain-English guide to reading COAs, analytical methods, batch matching, purity, identity and the limits of a test report.

Published by Aureon Research · Reviewed 11 August 2026

What is a Certificate of Analysis?

A Certificate of Analysis, usually shortened to COA, is a document associated with a particular material or batch. Its purpose is to present identifying information and analytical results supplied by the document issuer. The useful question is not simply whether a COA exists, but what was tested, by whom, with which method, and which batch the document refers to.

A COA is evidence with boundaries.An analytical result only supports the characteristic that was actually measured. One test result should not be stretched into claims about characteristics the method did not assess.

A practical COA checklist

1. Match the material and batchCheck that the product name, batch or lot identifier and any sample identifier correspond with the material you are reviewing.
2. Identify the issuing laboratory or organisationLook for who produced the document and whether the report contains enough information to trace the analysis.
3. Read the analytical methodHPLC, mass spectrometry and other methods answer different questions. The method matters as much as the headline result.
4. Separate identity from purityA result consistent with molecular identity is not automatically a purity measurement. Equally, a chromatographic purity figure is not by itself proof of molecular identity.
5. Check dates and report referencesAnalysis date, report date, document number and revision information help establish which record you are looking at.

Common analytical terms

HPLC

High-performance liquid chromatography separates components in a sample under defined analytical conditions. Depending on the method and reporting approach, a chromatogram may be used to estimate relative purity or quantify an analyte. Always read the method and basis of calculation rather than assuming every HPLC percentage means the same thing.

Mass spectrometry

Mass spectrometry measures mass-to-charge information from ions and can provide evidence consistent with molecular identity. It is often complementary to chromatographic analysis rather than interchangeable with it.

Purity and assay

These terms are sometimes used loosely. Purity commonly describes the proportion of a target component relative to detected components under a stated method. Assay generally refers to the measured amount or concentration of a target substance. The report should state what the number represents.

What a COA cannot tell you automatically

A COA does not automatically establish sterility, endotoxin status, biological activity, suitability for a particular experiment, stability after opening or any property that was not actually tested and reported. Those questions require their own methods, specifications and controls.

Products with a COA link

Retatrutide 30mgProduct page →MT-2Product page →NAD+ 1000mgProduct page →