Peptide purity testing: HPLC & mass spectrometry
How HPLC and mass spectrometry characterize the purity and identity of research peptides.
How research peptides are characterized
Two analytical methods are commonly used to characterize research peptides: high-performance liquid chromatography (HPLC) and mass spectrometry (MS).
HPLC — purity
HPLC separates the components of a sample as they pass through a column, producing a chromatogram. The relative size of the main peak versus other peaks is used to estimate purity — how much of the sample is the target compound versus impurities.
Mass spectrometry — identity
Mass spectrometry measures the mass-to-charge ratio of ionized molecules, helping confirm a compound molecular weight and identity. It answers "is this the right molecule?" where HPLC answers "how pure is it?"
Reading the results
- A higher main-peak percentage on HPLC indicates higher purity.
- An MS result matching the expected mass supports correct identity.
- Methods and acceptance criteria vary by compound.
Frequently asked
What purity is typical?
It varies by compound and supplier. Review the reported value on the batch-specific COA.
Does testing make a product safe to use?
No. Testing characterizes the material for research reference only. Products are not for human or veterinary use.
Looking for research compounds?
Browse TagPep's catalog of research peptides and laboratory compounds, supplied with available batch documentation for laboratory research use only.
Browse research compoundsEducational content for research reference only — not medical, veterinary, or personal-use advice. Products referenced are research compounds supplied for laboratory research use only and are not intended for human or veterinary use.