Peptide Reference

What Is HPLC Testing for Peptides?

Reviewed by our laboratory team · Last updated 2026-07-03

HPLC (high-performance liquid chromatography) is a chromatographic method that separates a peptide sample into its components based on differential interaction with a stationary phase. Peptide purity is reported as the percentage area under the main chromatogram peak versus total peak area, standardly at UV 214 nm.

Key facts

Full name
High-Performance Liquid Chromatography
Common mode
Reverse-phase (C18 column)
Detection
UV at 214 nm (amide bond)
Purity metric
% area of main peak

Why 214 nm

The peptide bond absorbs strongly at ~214 nm. Detection at this wavelength catches every peptide-containing component regardless of aromatic side chains.

Extended research context

The Peptide Reference deep dive

Deep dive: what 'peptide' actually means

A peptide is a short chain of amino acids linked by peptide bonds, typically 2–50 residues. Above that boundary the molecule is usually called a protein. Peptides can be endogenous (produced by the body) or synthetic (manufactured by solid-phase peptide synthesis, SPPS). The 'research peptide' category refers specifically to synthetic peptides supplied for laboratory use — not medicines, not supplements.

Why HPLC and mass spec together

HPLC (High-Performance Liquid Chromatography) reports the purity of a batch by measuring what percentage of the sample matches the target peptide's retention time. Mass spectrometry independently confirms the target's molecular weight. Together they answer two different questions: 'is it clean?' and 'is it the right molecule?'. A CoA that reports only one is incomplete.

How to read a Certificate of Analysis

A complete peptide CoA lists: batch number, HPLC purity (area %), mass-spec measured mass vs theoretical, water content (Karl Fischer), acetate/counterion content, appearance, and often endotoxin and residual solvents. Learn to spot the missing fields — that's usually where quality claims fall apart.

Research applications

  • Reference standards for analytical method development
  • Comparator peptides in receptor-binding assays
  • Stability testing of lyophilised material
  • Formulation R&D for topical and aqueous carriers
  • Teaching material for peptide chemistry courses

Handling checklist

  • Confirm HPLC ≥98% and mass-spec identity on CoA
  • Store lyophilised at −20 °C long-term
  • Reconstitute with bacteriostatic or sterile water only
  • Aliquot to minimise freeze/thaw cycles
  • Label vials with date, concentration, and batch

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

Buying a peptide without a CoA

Fix: Insist on an in-batch HPLC + mass-spec certificate before purchase.

Using DI water for reconstitution

Fix: Use bacteriostatic (0.9% benzyl alcohol) or sterile water only.

Storing lyophilised vials at room temperature long-term

Fix: Freeze at −20 °C; short-term 2–8 °C is acceptable for weeks, not months.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Related questions researchers ask

  • What is a research peptide?
  • How is peptide purity measured?
  • Why is HPLC the standard purity assay?
  • What information is on a peptide CoA?
  • Why are research peptides lyophilised?

Frequently asked questions

Can HPLC identify the peptide?
HPLC quantifies; identification requires mass spectrometry to confirm molecular mass.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab (external, rel="nofollow").

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Research use only. The information above is provided for scientific and educational reference. Compounds referenced are not approved for human use and are supplied for in vitro research or reference-material purposes only. No efficacy, safety, or therapeutic claims are made.