What a third-party COA is

A COA reports tests performed on a specific lot. Independence matters because in-house QC is process control: useful, but commercially conflicted. A separately incorporated analytical laboratory does not share that pressure. Agreement or disagreement between in-house and independent methods is itself a data point.

What a complete report should contain

• Sample identification: product name, lot number, sample date.
• Identity: mass spectrometry or another orthogonal method matching expected mass.
• Purity by HPLC: area-percent plus the chromatogram and method (column, mobile phase, gradient, detector).
• Net peptide content where applicable (amino-acid or elemental analysis). This is not the same as HPLC purity.
• Water content for lyophilized material, often Karl Fischer.
• Microbial or endotoxin testing when relevant to the work.
• Laboratory identification: name, location, accreditation if any, analyst.
• Dates of analysis and of the report.

Red flag. A document labeled “COA” that is only a final percentage, with no chromatogram or method, is not a meaningful certificate. The trace and the method are the evidence; the percentage is the summary.

How to verify a report

1. Search the issuing lab independently. A real laboratory has a public presence and an address.
2. Match the lot printed on the vial to the lot on the report.
3. Look at the chromatogram, not only the number. A clean baseline and a dominant, well-separated target peak are visual checks. Wide, asymmetric, or unresolved shoulder peaks can hide impurities in the main peak.
4. Confirm mass-spec data when present: observed mass should match the theoretical mass within instrument tolerance.
5. Prefer lot-by-lot reports over a single “representative” certificate used for every vial.

Reproducible work depends on knowing what is in the vial. A label percentage without a matching lot report can put unidentified synthesis byproducts into every downstream assay.

Questions a supplier should be able to answer

• Who is the analytical laboratory, and can I see their identity?
• Are reports lot-specific, or only representative?
• Is the chromatogram included, or only a percentage?
• Is mass-spectrometry identity included?
• How is net peptide content measured?

Heavy Kingdom practice. Lot reports are listed in the documentation hub when they are published. If a report is not posted yet, email support@heavykingdom.com and match any document to the lot on the vial before laboratory use. A product photo is not a substitute for a lot-specific report.