Alizarin yellow GG (CAS: 584-42-9)

Performance specification

Appearance description: yellow powder. Soluble in hot water and ethanol, slightly soluble

in cold water. Sulfuric acid solution and ethanol solution are golden, encounter a titian, dilute

produce lime precipitation, nitric acid a yellow amber colour.

Physical parameters: melting point: > 300 C

Application Description 

Used as a pH indicator, pH 10.0 (bright yellow) ~ 12.0 (brown). Also used as a biological stain.

Commonly used 100 ml50%0.1 g soluble in ethanol.

Hazard statements 

Dangerous code: Xi

The level of danger: R36/37/38

Security level: S24/25 to 36-26

Preparation method

Nitroaniline between the diazotization and coupling with sodium salicylate: add nitroaniline

between 100 g to 400 ml of hydrochloric acid and 1.5 L water, heat to dissolve after cooling to

0 to 5 ℃, and 540 g saturated solution of sodium nitrite soluble in water. Diazotization always

maintain 5-10 ℃, the temperature will diazonium salt after nitriding, slowly add 116 g saturated

aqueous solution of sodium salicylate, below 15 ℃ temperature control and strictly control the

pH in 6, continue to stir the 4 h, the place for the night, filtering products. Products used for hot

water dissolving, activated carbon, and a little sodium hydroxide added, to control the pH 9,

filtering, cooling, crystallization is the finished product.