Methodological standard · §5
CEI-MS-04 — 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 |
|---|---|---|
| Cell drift before titration | ≤ 20 µg/min | Cell dryness |
| Water-standard recovery | 97.5–102.5 % | System accuracy |
| Relative standard deviation, three determinations | ≤ 5 % | Repeatability |
| Sample mass | 5–20 mg | Adequate titre against blank |
§5.2Acceptance criteria
- Water content is reported as determined. The Institute sets no universal limit, but records that a lyophilised peptide with water above approximately 10 % should be regarded as having a materially shortened solid-state shelf life because residual water mobilises deamidation and aspartimide formation.
- A determination without a reported cell drift and standard recovery is not reportable.
§5.3Limitations
Compound Evidence Institute · CEI-MS-04/5 · https://compoundevidence.com/methods/water-karl-fischer/acceptance-criteria/ · retrieved 30 July 2026