Check what the percentage represents
HPLC purity measured by UV detection describes signals under a defined analytical method. It does not directly state the target peptide’s mass fraction in the entire vial of powder. [1]
Content has a separate definition
A lyophilized product can contain peptidic material, counterions and moisture. Net peptide content differs from chromatographic purity and may include peptidic impurities. Read the definition used in the report. [2]
Ask a specific testing question
Tell the laboratory whether you need purity, target-peptide mass per vial or solution concentration. Agree the reporting units and calculation basis. LANHENG confirms the testing objective and deliverables when discussing your request.