What Is Mass Spectrometry?

Mass spectrometry ionises a sample and measures the mass-to-charge ratio of the resulting ions. Because a peptide's amino acid sequence determines its exact mass, the measured mass is a strong identity check.

A reported mass matching the theoretical mass of the claimed sequence is meaningful evidence that the molecule is what it claims to be.

Identity plus purity

Together, mass spectrometry and HPLC answer the two separate questions any batch document should address: is it the right molecule, and how much of the sample is it?