Tartrazine

Brief Overview 

Tartrazine is a bright yellow anionic and hydrophilic powder used as a food coloring. It is a synthetic lemon yellow and yellow azo dye. It can also be used with Brilliant Blue FCF (FD&C Blue 1, E133) or Green S (E142) to produce various green shades. It is famously known by its E number E102.
The dye consists of trisodium 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-1H-pyrazole-3- carboxylate.

Manufacturing Process

Tartrazine is manufactured by reacting diazotized 4-aminobenzenesulfonic acid (sulfanilic acid, SA) with 5-oxo-1-(4-sulfophenyl)-2-pyrazoline-3-carboxylic acid (Pyrazolone T, PyT). It can also be obtained by reacting with another compound, such as methyl ester, ethyl ester, or a salt of this carboxylic acid. The resulting compound is purified and isolated as the sodium salt. 

Another method for manufacturing tartrazine is condensing phenylhydrazine-p-sulfonic acid with dioxosuccinic acid or oxalacetic acid derivatives.

Food Industry

Tartrazine is used in desserts, confectionaries, chips, beverages, snacks, spreads, jams, and other processed foods.

Household Items

Tartrazine is used in liquid and bar soaps; lipsticks, lip balms, nail polish; other cosmetic products mainly for the color.

Pharmaceutical Industry

Some medications include tartrazine to give a yellow, orange, or green hue to a liquid, capsule, pill, lotion, or gel, primarily for easy identification.

Other Applications

Other products, such as household cleaning products, paper plates, pet foods, crayons, inks for writing instruments, stamp dyes, face paints, and envelope glues, may also contain tartrazine.