Glossary · 2026-09-24
By Alice Kay · Last reviewed 24 Sep 2026
Mass spectrum on a peptide COA
Research-use notice: This article summarizes published scientific literature for educational purposes. It is not medical advice and does not provide dosing, administration or human-use information. Findings described in the literature do not apply to any BlueNex Labs product, which is supplied only for in-vitro laboratory research and not for human or animal use.
A mass spectrum plots ion signal against mass-to-charge. On a peptide lot report it is the usual identity evidence: an observed ion compared with a mass calculated for a stated species. Free peptide, acetate, and trifluoroacetate are different species. Sodium and potassium adducts move the observed ion by a familiar offset when the report says so.
If the observed mass matches none of the species you can justify from the sequence and the words on the PDF, stop and hold the vial. A high area percent does not repair a mass mismatch. For the guide, see how to read a peptide COA, next to the LC-MS term. Research use only.
Published lot files for this catalogue are indexed in the certificates library. This definition does not add a report, and it does not assign a task identifier. Research use only.
Frequently asked questions
- Should a receiver add an adduct mass that the report does not mention?
- No. File the species the laboratory named. If the match is unexplained, the vial stays out of the study file until that line is clear.
- Does LC-MS always include a chromatogram and a spectrum?
- Only when both are in the file you opened. Record the pages that are present. Do not describe a missing spectrum as if it were attached.
Research use only. BlueNex Labs does not provide medical or veterinary advice. Confirm your institution’s policies before purchase. How a comparison or class note is checked sits on documentation standards. Articles are written and reviewed by Alice Kay, Ph.D.