| Molecular Formula: C21H18O5S |
| Molecular Weight: 382.43 |
| Properties: reddish brown powder; soluble in basic solution; slightly soluble in methanol and ethanol; almost insoluble in acetone and benzene; insoluble in aethers. |
| Use: As acid-base indicator, and colour layer analytical reagent. |
| Storage: Closed tight. |
| PH range |
6.5(yellow)-8.5(purple) |
| Ethanol solubility test |
Qualified |
| Drying loss |
≤3.0% |
| Residue on ignition(sulphate) |
≤0.2% |
| Maximum Absorption Wavelength, nm: |
| λ1(PH6.5) |
432-436 |
| λ2(PH8.5) |
571-574 |
| Mass absorption eoefficient, L/(cm,g): |
| a1(λ1, PH6.5, dry sample) |
49-67 |
