Allopurinol EP Impurity A Hemisulfate CAS 27511-79-1
| CAS No. | 27511-79-1 |
| Molecular Formula | 2*C4H6N4O |
| Molecular Weight | N/A |
| 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.
As a process- or degradation-related impurity, Allopurinol EP Impurity A Hemisulfate (CAS 27511-79-1, C4H6N4OH2O4S) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
The molecular framework of Allopurinol EP Impurity A Hemisulfate (C4H6N4OH2O4S) is characterized by a carbohydrate-derived structure, an amide group, a sulfone group. 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.
As a certified reference material (CRM), Allopurinol EP Impurity A Hemisulfate 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 | 2*C4H6N4O H2O4S |
| Molecular Weight | 224.19 g/mol |
| 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) | 3.0 |
| UV Absorption | UV-absorbing |
| CAS Registry Year (est.) | 1964 |
| Nitrogen Atoms | 4 |
| Sulfur Atoms | 1 |
Related Allopurinol Standards
- Allopurinol EP Impurity D (USP RC D) (CAS 1260243-04-6)
- Allopurinol EP Impurity C (CAS 1346604-13-4)
- Allopurinol Riboside (CAS 16220-07-8)
- Allopurinol impurity 30 (CAS 18197-22-3)
- Allopurinol EP Impurity D (CAS 19750-02-8)
- Allopurinol EP Impurity B (CAS 22407-20-1)
- Allopurinol impurity 25 (CAS 2303964-80-7)
- Allopurinol EP Impurity E (CAS 31055-19-3)
Recommended Standards
- Baloxavir Marboxil Impurity 212 (CAS CATO-C4X-2108212)
- Paliperidone Impurity 34 (CAS 1172995-13-9)
- Nemonoxacin Impurity 92 MalicAcid (CAS CATO-C4X-312892)
- 2-Cyclopropoxy-6-isopropoxybenzoic acid (CAS 1243390-00-2)
- Pitavastatin Impurity 110 (CAS CATO-C4X-1037110)
- Bis(2-butoxyethyl) 2-Hydroxyethyl Phosphate Triester (CAS 1477494-86-2)
- 4-Methyl-6-phenyl-1,4-dihydropyridazin-3(2H)-one (CAS 52239-91-5)
- 17733-86-7 3-Chloro-N-[3-(trifluoromethyl)phenyl]propanamide 5921AD C10H9ClF3NO (CAS 17733-86-7)
- 3-Amino-5-methoxyisonicotinic acid 3-amino-5-methoxy-4-pyridinecarboxylic acid 3-amino-5-methoxypyridine-4-carboxylic acid 82673-73-2 (CAS 82673-73-2)
- Semaglutide impurity 203 (CAS CATO-C4X-2226203)
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