Methodological standard · §5
CEI-MS-03 — system suitability and acceptance criteria
The performance the system must demonstrate, and the criteria a result must meet to be reportable.
§5System suitability and acceptance criteria
§5.1System suitability
Table 1. System suitability criteria. A determination is reportable only where every criterion is met at the time of analysis.
| Parameter | Criterion | What it establishes |
|---|---|---|
| Reference-standard assay, relative standard deviation of five replicates | ≤ 2.0 % | Assay repeatability |
| Mass-balance residual | −2 % to +6 % | Completeness of the declared composition |
| Balance calibration | Within stated tolerance on the day of weighing | Gravimetric accuracy |
| Hydrolysis completeness, for amino-acid analysis | Recovery of a control peptide within 95–105 % | Hydrolysis adequacy |
§5.2Acceptance criteria
- Content is reported as determined with the method stated. The Institute sets no universal limit.
- A content figure obtained by difference is reported as such and is not treated as equivalent to a direct determination.
- A mass balance whose declared fractions sum above 102 % indicates an inconsistency in at least one determination and is not reportable.
- A certificate reporting purity without content is recorded as not conformant against CEI-MS-14.
§5.3Limitations
Compound Evidence Institute · CEI-MS-03/5 · https://compoundevidence.com/methods/peptide-content/acceptance-criteria/ · retrieved 30 July 2026