Benzoic acid, 3,3'-[1,2-ethanediylbis[(3-sulfo-4,1-phenylene)azo]]bis[6-hydroxy-, tetrasodium salt

Preparation

1,2-Bis(4-nitro-2-sulfophenyl)ethane double nitriding, and 2-Hydroxybenzoic acid (2 Moore) coupled.

Properties and Applications

green light yellow. Soluble in water for green light yellow, slightly soluble in alcohol. The strong sulfuric acid for gold in orange, no change after diluted. The dye solution to join strong hydrochloric acid for orange, precipitation; With strong sodium hydroxide solution for gold orange.