Purity
Definition
The percentage of the desired compound in a sample, as opposed to impurities, degradation products, or other contaminants. Research-grade peptides typically claim >98% purity.
Related Terms in Quality
Certificate of Analysis (COA)
A document from a laboratory (ideally third-party) that certifies the identity, purity, potency, and quality of a substance. Essential for verifying research peptide quality.
HPLC (High-Performance Liquid Chromatography)
An analytical technique used to separate, identify, and quantify components in a mixture. Used in COAs to determine peptide purity percentage.
Mass Spectrometry (MS)
An analytical technique that measures the mass-to-charge ratio of molecules. Used in COAs to confirm peptide identity and molecular weight.
Endotoxin
Toxic substances (lipopolysaccharides) released from the cell walls of gram-negative bacteria. Endotoxin testing (LAL test) is important for injectable peptide quality.
cGMP (Current Good Manufacturing Practice)
FDA regulations that ensure pharmaceutical products are consistently produced and controlled according to quality standards. Applies to licensed drug manufacturers, not research-grade suppliers.
CAS Number
A unique numerical identifier assigned by the Chemical Abstracts Service to every chemical substance. Each peptide has a specific CAS number (e.g., BPC-157: 137525-51-0) that allows unambiguous identification regardless of naming conventions.
INCI Name
International Nomenclature of Cosmetic Ingredients — the standardized naming system required on cosmetic product labels worldwide. Relevant for topical peptide products like GHK-Cu (INCI: Copper Tripeptide-1) and Matrixyl (INCI: Palmitoyl Pentapeptide-4).
Amino Acid Analysis (AAA)
A quality control test that determines the amino acid composition and quantity of a peptide sample. Used alongside HPLC and mass spectrometry on COAs to verify peptide identity.