Ethinylestradiol EP Impurity B CAS 1231-96-5
| CAS No. | 1231-96-5 |
| Molecular Formula | C20H22O2 |
| Molecular Weight | 294.39 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
As a certified reference material (CRM), Ethinylestradiol EP Impurity B meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
Ethinylestradiol EP Impurity B (CAS 1231-96-5) is a certified pharmaceutical impurity reference standard with the molecular formula C20H22O2 and a molecular weight of 294.39 g/mol.
Owing to a steroid core, a hydroxyl group, an ether linkage, Ethinylestradiol EP Impurity B is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 294.39 g/mol — guide the selection of appropriate sample preparation and analytical techniques. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).
This reference standard supports related-substances testing and method development in line with ICH Q3A/Q3B guidance on impurity control, and is suitable for system suitability testing and forced-degradation studies.
Physical & Chemical Properties
| Molecular Formula | C20H22O2 |
| Molecular Weight | 294.39 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 10.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1957 |
Related Ethinylestradiol Standards
- Ethinylestradiol EP Impurity I (CAS 67703-68-8)
- 17alpha-Ethinylestradiol (CAS 57-63-6)
- Ethinylestradiol EP Impurity A (CAS 4717-38-8)
- Ethinylestradiol-13C2 (CAS 2483735-63-1)
- Ethinylestradiol-d7 (CAS 2714413-57-5)
- Ethinylestradiol-d9 (CAS CATO-C4X-21909)
- Ethinylestradiol EP Impurity G (CAS 38002-18-5)
- Ethinylestradiol EP Impurity H (CAS 1350468-76-6)
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- (Tyr?)-C-Type Natriuretic Peptide (32-53) (human, porcine, rat) (CAS 142878-79-3)
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