Understand the source comparison
Identity Versus Purity
Purity, identity, and quantity answer different questions. Purity asks how much of the detected chromatographic signal belongs to the main component. Identity asks whether the main component is the expected peptide. Quantity asks how much peptide is actually p
No winner is assigned.
This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- Purity, identity, and quantity answer different questions. Purity asks how much of the detected chromatographic signal belongs to the main component. Identity asks whether the main component is the expected peptide. Quantity asks how much peptide is actually present. They are related, but none replaces the others.
- Purity
- HPLC area percent
- Does not prove structure alone
- Identity
- LC-MS observed mass
- Does not quantify all impurities
- Quantity
- Assay or content test
- Depends on method design
- Stability
- Time-based data
- Sequence and storage dependent