Eriochrome is to do titration indicator. Dubbed in aqueous solution or alcohol-soluble when used for the determination of calcium, magnesium, manganese, zinc and other metal ions, measured water hardness.
제조 방법
4-Amino-3-hydroxynaphthalene-1-sulfonic acid diazotization, and Naphthalen-1-ol coupling.
Purification Methods
Free it from metallic impurities by three precipitations from aqueous solution by addition of HCl. The precipitated dye is dried at 60o under vacuum and converted into the Na salt with the calculated amount of alkali. It is an indicator in the complexometry of Al, Fe and Zr. [Beilstein 16 III 319.]
