Confirming identity with mass spectrometry

Mass spectrometry (MS) ionises a sample and measures the mass-to-charge ratio of the resulting ions. For a peptide, the observed mass is compared with the theoretical mass of the expected sequence.

Why it matters

Two peptides can look alike in a chromatogram. A matching mass confirms that the main component is the intended compound and not a close relative or a truncated sequence.

Reading the result

Certificates usually list the expected and observed mass. They should agree within the tolerance of the instrument used.

For research use only. Not for human or veterinary use.