Independent documentation guide

How to read a COA and verify laboratory documentation

A certificate of analysis can help identify what was tested, by which method and for which batch. It cannot prove claims that were never measured. Use this practical checklist before relying on any laboratory document.

01

Start with document identity

Before reading percentages or graphs, confirm that the document can be linked to a real sample and a specific batch.

Product and lotName, form, declared quantity and lot must match the supplied material.
Laboratory and sample IDLook for the testing laboratory, sample identifier and a way to verify the report.
Dates and versionCheck receipt, test and report dates, plus any revision or report number.

02

Identity, purity and quantity are different questions

HPLC

Relative purity profile

HPLC separates detected components. An area percentage can describe chromatographic purity under the stated method, but it is not automatically the net amount in the vial and does not identify every possible impurity.

LC-MS / MS

Mass-based identity support

Mass spectrometry compares observed mass signals with the expected molecule. Check whether the report shows the expected mass, observed result, charge states and interpretation—not only a pass label.

Content assay

How much material is present

Net content or peptide content requires a suitable quantitative assay and reference standard. A high HPLC purity percentage alone does not prove the stated milligram content.

03

Check what was not tested

A document may support identity or chromatographic purity while saying nothing about sterility, endotoxins, bioburden, residual solvents, water content, elemental impurities or stability. Never infer a result from an absent test.

Important limitation

A COA does not by itself establish suitability for human or veterinary use. That conclusion requires a different regulatory and quality framework.

04

A seven-step verification checklist

  1. Match the lot. Compare the product, lot and quantity on the document with the label.
  2. Identify the laboratory. Confirm the name, contact information and report or sample number.
  3. Check the date. Confirm when the sample was tested and whether the report was revised.
  4. Read the method. Look for method, instrument conditions, acceptance criteria and units.
  5. Separate claims. Do not treat identity, purity and quantity as interchangeable results.
  6. Inspect raw evidence. Prefer full chromatograms or spectra over cropped screenshots and pass badges.
  7. List missing tests. Record which quality attributes the report does not address.

05

Red flags in laboratory documents

  • No lot, sample number or test date.
  • The product name or declared quantity does not match the supplied material.
  • Only a summary table is shown, without chromatogram, spectrum or method details.
  • Purity is presented as proof of content, sterility or safety.
  • The laboratory cannot verify the report or the report identifier is missing.

Documentation question

Ask for the records behind a claim

Send a document-related question. Peptiva can clarify product specifications and available batch records, but does not provide medical advice, dosing or personal-use instructions.

FAQ

Three common COA questions

Does 99% HPLC purity mean the vial contains the stated amount?

No. Chromatographic purity and quantitative content are different measurements. The stated amount requires an appropriate quantitative assay.

Does LC-MS prove purity?

LC-MS can support molecular identity and reveal mass-related signals, but the conclusion depends on the method and data. It should not be treated as a universal purity or safety test.

Is a supplier-created COA enough?

It is evidence, not an automatic guarantee. Independent testing, a verifiable report number and a clear chain between sample and lot provide stronger support.