| CAS No. | CATO-C4X-33474 |
| Molecular Formula | C19H19NO5 |
| Molecular Weight | 341.36 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Atrasentan Impurity 4.
CATO supplies Atrasentan Impurity 4 (CAS CATO-C4X-33474), a pharmacopoeial impurity reference standard (molecular formula C19H19NO5, MW 341.36 g/mol) used for the identification and quantification of trace impurities in APIs.
Atrasentan Impurity 4 (C19H19NO5) contains a flavonoid core, an amide group, a hydroxyl group, an ether linkage. The carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
Recommended for quantitative analysis by HPLC, GC, LC-MS/MS, or GC-MS as an external calibration standard; it can also be used for spiked-recovery experiments, LOD/LOQ determination, and LC-MS/MS multiple-reaction-monitoring (MRM) calibration.
As a certified reference material (CRM), Atrasentan Impurity 4 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.
| Molecular Formula | C19H19NO5 |
| Molecular Weight | 341.36 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, acetonitrile, DMSO, water (slightly soluble) |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 11.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Nitrogen Atoms | 1 |