Tartrazine is a synthetic lemon yellow azo dye primarily used as a food coloring. It is also known as E number E102, C.I. 19140, FD&C Yellow 5, Yellow 5 Lake, Acid Yellow 23, Food Yellow 4, and trisodium 1-(4-sulfonatophenyl)-4-(4-sulfonatophenylazo)-5-pyrazolone-3-carboxylate) Tartrazine is a commonly used color all over the world, mainly for yellow, and can also be used with Brilliant Blue FCF (FD&C Blue 1, E133) or Green S (E142) to produce various green shades. E number: E102 (colors) Solubility in water: 20 g/100 mL CAS Number: 1934-21-0 Solubility: 18 g/100 mL in glycerol, negligible