Estriol EP Impurity A CAS 246021-20-5
| CAS No. | 246021-20-5 |
| Molecular Formula | C18H22O3 |
| Molecular Weight | 286.37 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Based on its molecular formula C18H22O3, Estriol EP Impurity A contains a steroid core, a hydroxyl group, an ether linkage; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 286.37 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. 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).
Estriol EP Impurity A (CAS 246021-20-5) is a certified pharmaceutical impurity reference standard with the molecular formula C18H22O3 and a molecular weight of 286.37 g/mol.
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.
As a certified reference material (CRM), Estriol EP Impurity A 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.
Physical & Chemical Properties
| Molecular Formula | C18H22O3 |
| Molecular Weight | 286.37 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| 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) | 8.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2025 |
Related Estriol Standards
Recommended Standards
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- Estradiol USP Related Compound C (CAS 571-92-6)
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- Doxylamine Impurity 5 (CAS 99430-77-0)
- Budesonide EP Impurity L (Mixture of Epimer) (CAS 216453-74-6)
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- Ruxolitinib Impurity 128 (CAS CATO-C4X-2058128)
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- (3-Amino-2-methyl-phenyl)-carbamic acid tert-butyl ester (CAS 179898-27-2)
- 3-Chloro-2-methoxy-4-nitropyridine (CAS 1805648-70-7)
- 2-((Benzo[d][1,3]dioxol-5-ylmethyl)amino)ethan-1-ol hydrochloride (CAS 99075-94-2)
- Integrin Binding Peptide trifluoroacetate salt (CAS 278792-07-7)
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