HPLC tells us how pure a sample is. Mass spectrometry tells us what it is.
How it works
In electrospray ionisation mass spectrometry (ESI-MS) the peptide is ionised and separated by its mass-to-charge ratio. The resulting spectrum is used to calculate the molecular weight of the main component.
What we compare
The observed mass is compared with the theoretical molecular weight calculated from the sequence. A match within the method’s tolerance confirms identity.
On the certificate
- Theoretical molecular weight
- Observed mass
- Result: conforms / does not conform
Together, HPLC and MS give a complete picture of a batch — which is why both appear on every certificate in our COA library.
