COA spec checker
Enter the results from a peptide certificate of analysis and compare them with the limits you need. The checker confirms that the reported mass matches the sequence, flags results that are out of spec or missing, and walks through the checks that show whether the report is genuine.
1. Choose a starting spec
Presets are starting points. Edit any limit to match your own requirements.
2. Identity (mass spec)
3. Limits vs COA results
| Test | Limit | COA result | Required | Status |
|---|---|---|---|---|
| HPLC purity Main peak area % | ≥ % | Not reported | ||
| Largest single impurity | ≤ % | Not reported | ||
| Net peptide content AAA, nitrogen or assay | ≥ % | Not reported | ||
| Water (Karl Fischer) | ≤ % | Not reported | ||
| TFA / counterion content | ≤ % | Not reported | ||
| Bacterial endotoxin LAL test | ≤ EU/mg | Not reported | ||
| Heavy metals | ≤ ppm | No limit |
Results such as “<0.5” are read as 0.5. Leave a limit empty to skip that test.
4. Is the report genuine?
How the identity check works
The expected mass is calculated from the sequence using both average and monoisotopic residue masses. COAs often report a protonated ion such as [M+H]⁺ or [M+2H]²⁺, so choose the form shown on the report and the checker converts it to a neutral mass before comparing. A difference within the tolerance counts as a match. Modified peptides (lipidated, cyclic, PEGylated) need the expected mass entered manually.
Why “not reported” matters
A COA that lists only purity and identity says nothing about endotoxin, water or salt content. For cell or animal work, ask the supplier for those tests on your lot before buying. A missing result is not a pass.
Limits of the tool
The checker compares numbers you type in. It cannot tell whether those numbers are real. Use the authenticity checklist and the COA verification guide to judge that, and the net content calculator to estimate real peptide mass. This tool is not dosing, medical or safety guidance.