What a certificate of analysis is
A certificate of analysis is the released test record for one manufactured lot. For a lyophilized peptide it normally reports identity confirmation by mass spectrometry, purity as the main-peak area percentage from reverse-phase HPLC, the appearance of the cake, and the net peptide content of the vial. It records what was measured on that lot on a given day. It is a description of the material only — it says nothing about the behavior of that material in any biological system, and it is not an authorization to use it in one.