Peptide Testing & Purity Certification

May 18, 2026

Peptide Testing & Purity Certification

When it comes to research peptides, quality matters. Low-quality compounds can affect accuracy, consistency and overall research results.

At Peptide Coding UK every peptide is tested to verify both purity and identity before release.

HPLC Purity Testing

High-Performance Liquid Chromatography (HPLC) is used to measure peptide purity.

This process separates the target peptide from impurities and incomplete sequences, producing a chromatogram that shows:

Main peak = target peptide
Minor peaks = impurities or byproducts

For most laboratory applications, peptides should meet a purity standard of 98% or higher.

Mass Spectrometry Verification

Purity alone is not enough.

Mass Spectrometry (MS) is used to confirm the molecular weight and identity of the peptide, ensuring the compound matches the intended amino acid sequence.

This helps verify the peptide has been synthesised correctly.

Certificate of Analysis (CoA)

Every batch includes a Certificate of Analysis containing:

HPLC purity results
Mass Spectrometry data
Molecular weight
Batch number
Testing information

This provides full traceability and allows researchers to verify product quality with confidence.

Purity vs Net Peptide Content

These are not the same thing.

HPLC Purity measures how much of the sample is the target peptide
Net Peptide Content measures how much of the total powder weight is actual peptide material

Peptide powders can naturally contain small amounts of water or residual salts, which is why understanding both values is important for accurate laboratory calculations.