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.

Glossary · 2026-09-24

Scientific lead: Alice Kay, Ph.D.

Mass spectrum on a peptide COA

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. The guide is how to read a peptide COA, next to the LC-MS term. 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.