Research Education

PerformanceLabsUK supplies independently tested research reference materials for in vitro laboratory and scientific research use only, not for human or veterinary use.

HPLC and Mass Spectrometry: How Peptide Purity Is Actually Tested

Manufacturing & Testing

This page is educational and summarises general laboratory testing methods. It does not describe PerformanceLabsUK's specific testing procedures in detail.

Certificates of Analysis reference specific testing methods, but those method names are not always explained. This page gives a plain-terms explanation of the two techniques most commonly used to test peptide purity and identity: high-performance liquid chromatography and mass spectrometry.

What Is HPLC?

High-performance liquid chromatography, usually shortened to HPLC, is a technique used to separate the different components of a sample as it passes through a column under pressure. Different components travel through the column at different rates, which allows the main peptide to be distinguished from any minor impurities or side-products, and quantified as a percentage of the total sample.

What Is Mass Spectrometry?

Mass spectrometry measures the mass-to-charge ratio of molecules in a sample, which allows researchers to confirm the molecular identity of a peptide. Where HPLC is generally used to quantify purity, mass spectrometry is generally used to confirm that the molecule present actually matches the expected structure.

How the Two Methods Work Together

HPLC and mass spectrometry are often used together because they answer two different questions. HPLC establishes how much of the sample is the intended peptide, expressed as a purity percentage, while mass spectrometry confirms that the molecule detected is structurally correct. A Certificate of Analysis typically references results from both methods for this reason.

Comparing the Two Methods

Method	What it measures
HPLC	Purity, expressed as a percentage of the total sample
Mass spectrometry	Molecular identity, confirming the correct structure is present

Frequently asked questions

Does a purity percentage from HPLC guarantee the molecule is correct?

Not on its own. HPLC measures purity but does not confirm molecular identity by itself. This is why mass spectrometry is used alongside HPLC, to confirm the molecule detected matches the expected structure.

Are these the methods used to test compounds before dispatch?

Yes. Every batch is independently tested and issued with a batch-specific Certificate of Analysis before dispatch.

Are compounds discussed on this site intended for human or animal use?

No. All compounds discussed on this site are supplied strictly for in vitro laboratory research use only, and are not intended for human or animal administration.

Where can I find a Certificate of Analysis referencing these methods?

Batch-specific Certificates of Analysis are published in the PerformanceLabsUK COA library, referenced against the batch number shown on the product page.

Does this page constitute medical advice?

No. This page is provided for educational purposes only and does not constitute medical advice. Consult a qualified healthcare professional for any medical concern.

Research content only. PerformanceLabsUK Ltd, company number SC883220, registered in Scotland.