Research use only · Lyophilised material · Not a medicine · Not for human or veterinary use · Disclaimer
Sable Peptides

HPLC Purity for Research Peptides, Explained

HPLC Purity for Research Peptides, Explained is supplied for laboratory research only. Key facts are below; stored as lyophilised powder.

Last verified 12 Oct 2026.

A CoA for every lot; each vial carries a printed lot number that matches it. Ask with the lot number and we send it.

The short answer

HPLC purity is the main peak's share of total peak area in a chromatogram, usually reversed-phase with UV detection at 214–220 nm. It measures related impurities, not identity and not net content by weight.

Research use only. Sable Peptides supplies laboratory reagents for in vitro and laboratory research by qualified people. Not a medicine. Not for human or veterinary use.

The short answer

HPLC purity is the main peak's share of total peak area in a chromatogram, usually reversed-phase with UV detection at 214–220 nm. It measures related impurities, not identity and not net content by weight.

How the separation works

In reversed-phase HPLC, peptides bind a hydrophobic C18 (or C8) stationary phase. A rising acetonitrile gradient elutes them in order of hydrophobicity. Ion-pairing agents such as TFA improve the peak shape (Mant et al., 2007). Truncated, deletion and modified sequences from synthesis usually elute near the main peak.

Reading the number

- Area % = main peak area ÷ total integrated area × 100. - Peaks outside the gradient window, or species that do not absorb UV, are not counted. - Integration choices (baseline, thresholds) move the result by tenths of a percent.

What to check on a chromatogram

1. The method: column, gradient, flow rate and wavelength. 2. A flat baseline and a symmetric main peak. 3. Any shoulder peaks hiding under the main peak. 4. The retention time, consistent with the reference where one is available.

Purity is not identity or content

Identity needs mass spectrometry; see HPLC vs MS. Net peptide content needs amino acid analysis or nitrogen determination. Sable has not yet published a separate guide on net peptide content. Counter-ions such as TFA add weight but are invisible at 214 nm, and residual TFA can affect cell-based assays (Cornish et al., 1999).

Quick reference

This page is the broader explainer. The condensed reference card with cited facts is at /ref/hplc-purity.

- /ref/hplc-purity - /learn/hplc-vs-mass-spectrometry - /learn/how-to-read-a-certificate-of-analysis

Sources

1. Mant CT et al.. HPLC analysis and purification of peptides. *Methods Mol Biol* 2007;386:3-55. PMID 18604941. PMC7119934. doi:10.1007/978-1-59745-430-8_1 2. Cornish J et al.. Trifluoroacetate, a contaminant in purified proteins, inhibits proliferation of osteoblasts and chondrocytes. *Am J Physiol* 1999;277:E779-83. PMID 10567002. doi:10.1152/ajpendo.1999.277.5.E779

*Last reviewed: 2026-10-10. Original Sable content; sources verified via PubMed E-utilities / Crossref / live HTTP checks on 2026-10-10.*

Last reviewed: 2026-10-10

How much does HPLC Purity for Research Peptides, Explained cost in the UK?

Frequently asked questions

What does HPLC purity measure?

The area of the main peak as a percentage of all UV-absorbing peaks detected under the stated method.

Why is 214–220 nm used?

Peptide bonds absorb strongly near 214–220 nm, so every peptide species is detected, not only those with aromatic residues.

Can two labs report different purities for one lot?

Yes. Column, gradient and integration settings change the separation and the baseline, so method details matter.

Does HPLC confirm identity?

No. Retention time alone does not prove identity. Mass spectrometry is needed for that.

What is TFA doing in HPLC?

Trifluoroacetic acid is a common ion-pairing additive that sharpens peptide peaks. It is also why many peptides are supplied as TFA salts.