Glossary
HPLC
High-performance liquid chromatography — the standard technique for separating a mixture and measuring chromatographic purity.
High-performance liquid chromatography (HPLC) pushes a dissolved sample through a packed column under high pressure; different components travel at different speeds and elute at different times, producing a chromatogram. For peptides the usual mode is reverse-phase HPLC. The percentage area of the main peak relative to all peaks is the chromatographic purity figure quoted on a certificate. HPLC measures how pure the material is, but not, on its own, how much peptide is present.
Covered in depth in Peptide laboratory testing methods.
Related terms
- Reverse-phase HPLC
- The most common HPLC mode for peptides, separating molecules by how strongly they interact with a non-polar column.
- Chromatogram
- The plot produced by a chromatography run, showing detector signal over time as separated components pass through.
- Retention time
- The time a component takes to travel through a chromatography column and reach the detector, characteristic under fixed conditions.
- Purity (chromatographic)
- The percentage of the main peak's area relative to the total peak area on a chromatogram — a measure of composition, not quantity.
- Mass spectrometry
- An analytical technique that measures the mass-to-charge ratio of ionised molecules to confirm a compound's identity by its molecular weight.