CI 45350

Resorcinol and Phthalic anhydride alone or in the presence of sulfuric acid Zinc chloride or condensation, namely for fluorescein, again into free acid.

ChEBI: Fluorescein (acid form) is a xanthene dye that is highly fluorescent and commonly used as a fluorescent tracer. It has a role as a radioopaque medium and a fluorescent dye. It is a xanthene dye, a member of benzoic acids, a hydroxy monocarboxylic acid, a cyclic ketone, a member of phenols and an organic heterotricyclic compound.

yellow. Soluble in water and ethanol as yellow, with strong green fluorescence. In concentrated sulfuric acid to yellow, with weak fluorescence, dilution after yellow, with yellow precipitation. Dye aqueous solution to join sodium hydroxide color dark, with dark green fluorescence. The dye for C.I. Acid Yellow 73 free Acid. Used in cosmetics coloring.

Standard	Light Fastness	Heat-resistant(℃)		water	Sodium Carbonate(5%)	Hydrochloric acid(5%)
		Melting point	Stable
ISO	Poor			Insoluble	General	No change