| CAS No. | 653570-18-4 |
| Molecular Formula | C10H7NO3S |
| Molecular Weight | 221.23 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
This reference standard is suitable for quantitative analysis on major chromatographic platforms including HPLC, GC, LC-MS/MS, and GC-MS, serving as an external calibration standard or a system suitability test reference material.
4-Hydroxy-8-mercaptoquinoline-3-carboxylic acid (CAS 653570-18-4), molecular formula C10H7NO3S and molecular weight 221.23 g/mol, is a CATO reference standard with documented purity and traceability.
Based on its molecular formula C10H7NO3S, 4-Hydroxy-8-mercaptoquinoline-3-carboxylic acid contains a nitrogen-containing heterocyclic scaffold, an amide group, a sulfone group, a hydroxyl group, an ether linkage; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 221.23 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
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.
| Molecular Formula | C10H7NO3S |
| Molecular Weight | 221.23 g/mol |
| Purity | 97%+ |
| 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) | 8.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1985 |
| Nitrogen Atoms | 1 |
| Sulfur Atoms | 1 |