DESCRIPTION

Brilliant Blue occurs as a dark purple to bronze powder or granules. It is principally the disodium salt of ethyl[4-[p-[ethyl(m-sulfobenzyl)amino]-α-(o-sulfophenyl)benzylidene]-2,5-cyclohexadien-1-ylidene](m-sulfobenzyl)ammonium hydroxide inner salt. It dissolves in water to give a solution green-blue at neutrality, green in weak acid, and yellow in stronger acid. Addition of base to its neutral solution produces a violet color only on boiling. When dissolved in concentrated sulfuric acid, it yields a yellow solution that turns green when diluted with water. It is slightly soluble in ethanol.