How to read a peptide certificate of analysis

Start with record identity

Confirm that the product name, batch or lot identifier, sample identifier and document version match the material being reviewed. A certificate that cannot be linked to the physical unit is not useful release evidence.

Separate method from conclusion

Record which analytical technique produced each result. Chromatographic purity, mass-based identity and quantitative content answer different questions and should not be presented as interchangeable conclusions.

Check the evidence chain

The record should preserve the testing entity, report date, method reference, acceptance criteria, observed result and authorised release decision. Missing fields should remain visibly unavailable rather than being inferred.

Procurement checklist

Request the exact lot identifier, approved specification, source report, method reference, sample-custody information and document-control history.

• Do the identifiers match the physical material?
• Is each result tied to a named method?
• Are specification limits separated from observed results?
• Is the testing source identifiable?
• Is the document current and controlled?

Primary reference

FDA guidance on analytical procedures explains that analytical methods must be suitable for their intended purpose and appropriately documented. This principle supports method-specific interpretation rather than relying on an isolated headline number.