Eriochrome Cyanine R
If you find any inaccurate information, please let us know by providing your feedback here
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
C23H15Na3O9S 536.40 CAS RN®: 3564-18-9.—Dark, red-brown powder. Freely soluble in water; insoluble in alcohol.
Solubility: 200 mg in 100 mL of water yields a solution that remains clear and free from undissolved matter for 30 minutes.
Loss on Drying 〈731〉: Dry it in vacuum over silica gel to constant weight: it loses not more than 2% of its weight.
Residue on Ignition (Reagent test): 0.5 g, treated with 1 mL of sulfuric acid and 2 mL of nitric acid, yields between 42.0% and 44.0% of the dry weight (theoretical yield is 42.9% of Na SO ).
Sensitiveness: Add 2 mL of a solution (1 in 1000) to 1 mL of aluminum sulfate solution (1 in 10,000), heat at 37 ± 3° for 5 minutes, cool, and add 1 mL of sodium acetate TS: a strong red to red-violet color is produced in not more than 5 minutes.
