Peptide analytical guide
HPLC and MS answer different peptide quality questions
Use HPLC to review separation and purity under a defined method, and MS to support molecular-mass or identity confirmation. Neither should be read without method context.
HPLC does not by itself prove identity, and MS does not by itself describe chromatographic purity. Buyers should define the decision each method must support.
Method roles
What each method contributes
The exact analytical package depends on material, intended use and buyer acceptance criteria.
| Question | HPLC | MS |
|---|---|---|
| Primary role | Separation and relative purity under defined conditions | Molecular-mass or identity support |
| Buyer should request | Method, column, mobile phase, detector, gradient, integration and chromatogram | Technique, expected mass, observed result, charge interpretation and spectrum |
| Common limit | Co-elution and method differences can affect interpretation | Mass agreement alone does not establish chromatographic purity |
| Acceptance | Define limits, data format, reference standards and investigation rules before testing | |
Buyer request
What to specify in the RFQ
- Required identity and purity methods
- Acceptance limits and reporting units
- Raw chromatogram or spectrum needs
- Method or instrument detail required
- Reference standard expectations
- Handling of unknown or individual impurities
Do not compare percentages alone: analytical results are meaningful only with the method, sample and reporting rules that produced them.
FAQ
Analytical package questions
Set expectations before quotation.
Do HPLC and MS answer the same peptide question?
No. HPLC commonly supports separation and purity assessment under a defined method, while MS supports molecular-mass or identity confirmation. The project may require both.
Is an HPLC purity percentage comparable across every method?
Not automatically. Buyers should review method conditions, detection, integration and sample preparation before comparing values.