| CAS No. | CATO-C4X-213421 |
| Molecular Formula | C10H13ClO2 |
| Molecular Weight | 200.66 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
The occurrence of Tulobuterol Impurity 21 is closely related to a carboxylic acid group, a hydroxyl group, an ether linkage, chlorine substitution, an aromatic ring system in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
CATO supplies Tulobuterol Impurity 21 (CAS CATO-C4X-213421), a pharmacopoeial impurity reference standard (molecular formula C10H13ClO2, MW 200.66 g/mol) used for the identification and quantification of trace impurities in APIs.
Owing to a carboxylic acid group, a hydroxyl group, an ether linkage, chlorine substitution, an aromatic ring system, Tulobuterol Impurity 21 is typically off-white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 200.66 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).
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.
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 | C10H13ClO2 |
| Molecular Weight | 200.66 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (slight halide-like odor) |
| Purity | >95% |
| Storage | Store at room temperature, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 4.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Halogen Content | Cl-containing |