Analytical reports often place a purity percentage near the top of the page. That number is useful, but it is also one of the easiest results to overinterpret.
Purity and identity are different analytical questions. A report should be read according to the method actually performed and the parameter the method is intended to assess.
What does purity describe?
In chromatographic analysis, a reported purity value commonly describes the proportion of the detected chromatographic response associated with the target peak under the stated method and conditions. It is therefore important to review the method, detector, integration and reporting basis rather than reading the percentage in isolation.
A high chromatographic purity result does not automatically establish what the material is. It also does not, by itself, establish the amount present in a vial or container.
What does identity describe?
Identity testing addresses whether the tested sample is consistent with the stated material under the reported method. Depending on the material and laboratory workflow, identity evidence may involve techniques such as mass spectrometry or other material-appropriate analytical methods.
The key point is simple: identity asks “what is it?” while purity asks “how much of the measured analytical response is associated with the target relative to other detected components under this method?”
Why the distinction matters
Imagine a report that shows 99%+ purity but does not include an identity test. The purity result may indicate a dominant chromatographic peak, but it should not be presented as independent proof that the peak represents the stated compound unless the identity question has also been addressed.
The same separation applies to other parameters. A purity percentage does not prove:
- measured content or quantity,
- endotoxin status,
- microbial status or sterility,
- heavy-metal or elemental-impurity status, or
- batch linkage to inventory held by a seller.
Each of those questions requires its own evidence where relevant.
How Avelqor reads analytical reports
Avelqor Labs separates analytical parameters instead of combining them into a single generic “tested” claim. On our documentation pages, identity, purity, content, endotoxin, microbial testing and elemental analysis are described according to the evidence actually supplied.
If a parameter was not tested, it should be treated as not tested rather than inferred from a different result.
A practical review sequence
- Identify the material and reported lot.
- Identify the issuing laboratory or supplier.
- Check the analytical method and the parameter it addresses.
- Review the numerical result together with units and reporting limits.
- Check whether identity and purity were assessed separately.
- Confirm whether the report can be linked to the exact inventory lot being supplied.
For a more complete review process, see How to Read a COA for Research Materials and the Research Material Documentation Checklist.
Related research notes
Continue with Why Batch Linkage Matters in Analytical Documentation and What a QR Code on a COA Can — and Cannot — Prove. You can also review the full Avelqor Research Library.
You can review Avelqor’s current COA & Batch Verification records.
Research documentation only: this article discusses analytical documentation and does not provide medical, dosing, treatment or administration guidance.