Aspirin Impurity 25 CAS 38160-63-3
| CAS No. | 38160-63-3 |
| Molecular Formula | C7H7NO3 |
| Molecular Weight | 153.14 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
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.
Aspirin Impurity 25 (CAS 38160-63-3) is a certified pharmaceutical impurity reference standard with the molecular formula C7H7NO3 and a molecular weight of 153.14 g/mol.
Owing to an amino-acid-derived structure, an amide group, a hydroxyl group, an ether linkage, Aspirin Impurity 25 is typically off-white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 153.14 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).
The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.
Physical & Chemical Properties
| Molecular Formula | C7H7NO3 |
| Molecular Weight | 153.14 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (faint amine-like odor) |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO, water |
| 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.) | 1967 |
| Nitrogen Atoms | 1 |
Related Aspirin Standards
- Aspirin Impurity A (CAS 99-96-7)
- Aspirin Impurity C / Mesalazine EP Impurity H (CAS 69-72-7)
- Aspirin Impurity 12 (CAS 13110-96-8)
- Aspirin Impurity 21 (CAS 606-19-9)
- Aspirin Impurity 22 (CAS 601-97-8)
- Aspirin Impurity 13 (CAS 57009-12-8)
- Aspirin Impurity 17 (CAS 77527-00-5)
- Aspirin Impurity 27 (CAS 25714-71-0)
Recommended Standards
- Metronidazole Impurity 26 (CAS 5006-79-1)
- Allopurinol impurity 12 (CAS CATO-C4X-145812)
- Mesalazine EP Impurity F (CAS 570-23-0)
- Gadobutrol Impurity 111 (CAS 619-73-8)
- Argatroban Impurity 11 (CAS CATO-C4X-100711)
- Isosorbide Dinitrate Impurity 6 (CAS 65940-93-4)
- Acyclovir Identification Reference (API& EP Impurity C & EP Impurity I Mixture) (CAS CATO-C4X-101027)
- 6-Bromo-4-fluoro-7-methyl-1H-indole (CAS 1167056-57-6)
- 1-Ethyl-3-methyl-N-(4-morpholinophenyl)-1H-pyrazole-5-carboxamide (CAS 1205451-80-4)
- Pranoprofen Impurity 17 (CAS CATO-C4X-181117)
- (S)-2-amino-2-(3-bromo-4-fluorophenyl)ethan-1-ol (CAS 1213676-90-4)
- 1,4-Dimethyl-1h-indazol-6-ol (CAS 1416712-62-3)
- 1-(6-Chloropyridin-2-yl)-4-(1H-1,2,4-triazol-1-yl)-1H-pyrazol-5-yl dimethylcarbamate (CAS 955975-72-1)
- D-[γ-Glu](Side Chain)-Semaglutide (CAS CATO-C4X-2226254)
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