Three measurements, one material
Purity, identity, and content are three different questions, and a single number cannot answer all three. Purity is the fraction of the sample that is the target molecule; identity is confirmation that the molecule is what it should be; content is how much active material is actually present.
The errors each measurement controls
HPLC purity controls for contaminants and degradation products. Mass spectrometry controls for sequence errors and molecular-weight mismatches. Peptide content controls for the difference between gross vial fill and actual active material.
A material can be pure but the wrong sequence, or the right sequence at low purity. Checking only one number leaves the other failure modes open.
Reading them together
A complete certificate presents the three measurements side by side for a single lot. Read them as a set: identity first (is it the right molecule?), then purity (how clean is it?), then content (how much active material per vial?).
What KAM Research publishes
Each batch certificate reports purity, identity, and content together, tied to a lot number and retrievable by QR. That set of three is what makes a material traceable to a specific, tested batch.