Mass Spectrometry and Peptide Identity Verification
Key takeaways
- Every peptide has a precise molecular weight set by its sequence.
- Mass spectrometry measures that weight and compares it to the theoretical value to confirm identity.
- A complete Certificate of Analysis pairs mass spec (identity) with HPLC (purity).
The core idea
Every peptide has a precise molecular weight determined by its amino-acid sequence. Mass spectrometry (MS) measures that weight with high accuracy, letting a lab confirm that the material in the vial matches the intended sequence.
How it works, briefly
The instrument ionizes the peptide and measures its mass-to-charge ratio. The observed mass is compared against the theoretical mass calculated from the sequence. A match within a tight tolerance is strong evidence the correct molecule is present; a mismatch flags a problem.
Identity plus purity
A complete Certificate of Analysis pairs MS (identity) with HPLC (purity). One confirms what the molecule is; the other confirms how much of it is the target. Neither alone is sufficient.
Frequently asked questions
Can mass spectrometry tell purity?
MS primarily confirms identity (molecular weight). Purity percentage comes from HPLC. The two are reported together on a complete CoA.
How is purity and identity verified for research use?
A research-grade reference standard should be characterized by HPLC (purity percentage) and mass spectrometry (identity and molecular-weight confirmation). Third-party testing and a published Certificate of Analysis tied to a lot number are the standard for any material used in reproducible research.
Related research compounds
References & further reading
For research and educational purposes only. The compounds discussed are research reference standards, not dietary supplements, drugs, or articles for human or veterinary use. Nothing here is medical advice, and no statement has been evaluated by the FDA.
