Patent blue V

CAS:3536-49-0
Product Description:Patent Blue V, also called Food Blue 5, Sulphan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, E 131, Patentblau V, or Cl 42051 and is a dark bluish synthetic dye used as a food coloring. As a food additive, it has E number E131. It is a sodium or calcium salt of [4-(α-(4-diethylaminophenyl)-5-hydroxy- 2,4-disulfophenylmethylidene)-2,5-cyclohexadien-1-ylidene] diethylammonium hydroxide inner salt. It has the appearance of a violet powder. In aqueous solution, its color will vary depending on the pH value of the medium: it is deep blue in a basic medium, yellowish-green in an acidous medium.