| CAS No. | 18181-08-3 |
| Molecular Formula | C11H15NO4 |
| Molecular Weight | 225.24 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Compared with other compounds in its class, the molecular weight of 225.24 g/mol gives Carbidopa EP Impurity B distinctive chromatographic separation conditions and mass-spectrometry parameter settings.
CATO supplies Carbidopa EP Impurity B (CAS 18181-08-3), a pharmacopoeial impurity reference standard (molecular formula C11H15NO4, MW 225.24 g/mol) used for the identification and quantification of trace impurities in APIs.
The molecular framework of Carbidopa EP Impurity B (C11H15NO4) is characterized by an amino-acid-derived structure, an amide group, a hydroxyl group, an ether linkage. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
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), Carbidopa 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.
| Molecular Formula | C11H15NO4 |
| Molecular Weight | 225.24 g/mol |
| Appearance | Off-white to pale yellow crystalline powder |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening |
| Degree of Unsaturation (DBE) | 5.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1962 |
| Nitrogen Atoms | 1 |