Product name:Food Yellow 3
CAS:2783-94-0
Molecular Formula:C16H10N2Na2O7S2
Formula Weight:452.37
Specification:100g
Description:
Food Yellow 3 is orange-red powder or particle, odorless. High moisture absorption. Good light and heat resistance. It is stable in citric acid and tartaric acid. The alkali turns a reddish brown. Soluble in water, neutral and acidic aqueous solution orange yellow, alkaline red brown, soluble in concentrated sulfuric acid orange liquid, diluted with water yellow. Soluble in glycerol, propylene glycol. Slightly soluble in ethanol.
Add p-aminobenzenesulfonic acid to 11-12, then slowly add sodium carbonate to dissolve it completely, filter; Cool to 0-5℃, then add 1.5-1.8 times (mass) hydrochloric acid of p-aminobenzenesulfonic acid, stir evenly and let stand, separate out fine 1-naphthalamine-4-sulfonic acid crystal, and cool to below 5℃. Diazo was obtained by slowly adding 1:2 (mass) sodium nitrite solution at 3-5℃ for diazo. After the reaction was finished, the solution was strongly acidic (blue) to Congo red test paper.
Stir 2-naphthol -6-sodium sulfonate and dissolve it in 20 times (mass) 75-80℃ water, then add some sodium carbonate (1/5 of the total), dissolve and then filter. Filtrate was put into the reactor, then the remaining sodium carbonate was added, stirred and cooled to 5-8℃. Then at 10-15℃ and ph 8-9, diazo solution was added slowly for coupling reaction for several hours.
After the reaction (2- naphthol - 6,8 - sodium disulfonate is slightly excessive), it was heated to 50-60℃, refined sodium chloride was added, stirred, it was naturally cooled to room temperature, and let stand for precipitation and crystallization. Dissolve the crystals in 15 times (mass) 70℃ clean water, add appropriate amount of sodium carbonate, make the solution slightly alkaline, add refined salt after filtration, stir and adjust the PH with hydrochloric acid to 6.5-7.0. Food Yellow 3 was obtained by standing, crystallization, separation and drying.