Mass Confirmation¶
Molecular Weight Verification¶
Principle¶
Mass confirmation uses mass spectrometry to verify that the peptide's molecular weight matches the theoretical value calculated from its amino acid sequence.
How It Works¶
| Ion | m/z (for a 1000 Da peptide) |
|---|---|
| [M+H]⁺ | 1001.5 |
| [M+2H]²⁺ | 501.3 |
| [M+3H]³⁺ | 334.5 |
| Deconvoluted mass | 1000.5 Da |
Expected vs. Actual¶
A mass match within ±1 Da confirms correct peptide identity. Mismatches indicate: - ±1 AA mass: deletion or insertion - ±18 Da: dehydration - ±16 Da: oxidation (Met, Trp) - +113 Da: TFA adduct
Report Format¶
| Parameter | Result |
|---|---|
| Theoretical MW | 1234.56 Da |
| Found MW (LC-MS) | 1234.45 Da |
| Mass error | -0.11 Da |
| Identity | ✅ Confirmed |
- Molecular Weight Verification — Review the section above for key parameters, methods, and quality criteria.
- Expected vs. Actual — Review the section above for key parameters, methods, and quality criteria.
Key Takeaways¶
- Molecular Weight Verification — Review the section above for key parameters, methods, and quality criteria.
- How It Works — See the section above for detailed parameters and specifications.
- Expected vs. Actual — Review the section above for key parameters, methods, and quality criteria.
- Report Format — Review the section above for key parameters, methods, and quality criteria.
🔗 Related: LC-MS Testing | LC-MS System | COA Understanding