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, Acid Yellow 23, Food Yellow 4, and Trisodium 1-(4-sulfonatophenyl)-4-(4-sulfonatophenylazo)-5-pyrazolone-3-carboxylate).
It is water soluble and has a maximum absorbance in an aqueous solution at 427±2 nm.
Tartrazine is a commonly used color all over the world, mainly for yellow, but can also be used with Brilliant Blue FCF (FD&C Blue 1, E133) or Green S (E142) to produce various green shades.
Read more about Tartrazine: Sensitivities and Intolerance, Possible Health Effects, Myths