Tartrazine

CA Index Name l//-Pyrazole-3-carboxylic acid, 4,5-dihydro-5-oxo-1 -(4-sulfophenyl)-4- [2-(4-sulfophenyl) diazenyl]-, sodium salt (1 3) 

Merck Index Number 9072 Chemical/Dye Class Pyrazolone Azo Molecular Formula Ci6H9N4Na309S2 Molecular Weight 534.36 

Handbook of Biological Dyes and Stains By R. W. Sabnis Copyright 2010 John Wiley Sons, Inc. 

Physical Form Bright orange-yellow powder Solubility Freely soluble in water soluble in ethanol, cellosolve insoluble in xylene 

Melting Point 300 °C Absorption (A,max) 425 nm Synthesis Synthetic methods 

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Phenylhydrazine condenses with acetoacetic ester to give a pyrazolone derivative which on methylation gives phenazone. The sulphonic acid similarly gives rise to the tartrazine dyestuffs. It is used to make indole derivatives by the Fischer process. 

C HgNjOjS. Colourless needles, with iH20. Prepared by reducing diazotized sulphanilic acid with an excess of sodium sulphite. It is a typical hydrazine in its reactions with ketones, and with acetoacetic ester. The latter reaction gives rise to the tartrazine dyestuffs, and is much used commercially. 

Analysis. The abiUty of silver ion to form sparingly soluble precipitates with many anions has been appHed to their quantitative deterrnination. Bromide, chloride, iodide, thiocyanate, and borate are determined by the titration of solutions containing these anions using standardized silver nitrate solutions in the presence of a suitable indicator. These titrations use fluorescein, tartrazine, rhodamine 6-G, and phenosafranine as indicators (50). 

The reaction is very common in pyrazolone chemistry. Since alkoxypyrazoles and tautomerizable pyrazolones undergo this reaction and 3-pyrazolin-5-ones, like antipyrine, do not, it is assumed that the reaction takes place at C-4 of the OH tautomer. Pyrazolone diazo coupling is an important industrial reaction since the resulting azo derivatives are used as dyestuffs. For instance, tartrazine (Section 4.04.4.1.3) has been prepared this way. 3,5-Pyrazolidinediones react with aryldiazonium salts resulting in the introduction of a 4-arylazo group. As has been described in Section 4.04.2.1.4(v), diazonium salts couple in the 3-position with indazole to give azo compounds. 

Many azo dyes, such as tartrazine (Section 4.04.4.1.3), are susceptible to reduction by bacterial reductases in the intestinal flora. Azo reduction is believed to proceed through a hydrazo intermediate that undergoes subsequent reductive cleavage of the nitrogen-nitrogen bond to yield the arylamine derivatives (B-80MI40406). 

For the reverse titration (chloride into silver nitrate), tartrazine (four drops of a 0.2 per cent solution per 100 mL) is a good indicator. At the end point, the almost colourless liquid assumes a blue colour. 

Use of tartrazine as indicator. Satisfactory results may be obtained by the use of tartrazine as indicator. Proceed as above, but add 4 drops of tartrazine (0.5 per cent aqueous solution) in lieu of the iron(III) indicator. The precipitate will appear pale yellow during the titration, but the supernatant liquid (best viewed by placing the eye at the level of the liquid and looking through it) is colourless. At the end point, the supernatant liquid assumes a bright lemon-yellow colour. The titration is sharp to one drop of 0.1 M thiocyanate solution. 

It is therefore necessary to remove the silver chloride by filtration. The filtration may be avoided by the addition of a little nitrobenzene (about 1 mL for each 0.05 g of chloride) the silver chloride particles are probably surrounded by a film of nitrobenzene. Another method, applicable to chlorides, in which filtration of the silver chloride is unnecessary, is to employ tartrazine as indicator (Section 10.82). 

Procedure C. Pipette 25 mL of the diluted solution into a 250 mL conical flask containing 5mL of 6M nitric acid, add a slight excess of 0.1M silver nitrate (30-35 mL) from a burette, and four drops of tartrazine indicator (0.5 per cent aqueous solution). Shake the suspension for about a minute in order to ensure that the indicator is adsorbed on the precipitate as far as possible. Titrate the residual silver nitrate with standard 0.1 M ammonium or potassium thiocyanate with swirling of the suspension until the very pale yellow supernatant liquid (viewed with the eye at the level of the liquid) assumes a rich lemon-yellow colour. 

The thiazide diuretics are contraindicated in patients with known hypersensitivity to the thiazides or related diuretics, electrolyte imbalances, renal decompensation, hepatic coma, or anuria. A cross-sensitivity reaction may occur with the thiazides and sulfonamides. Some of the thiazide diuretics contain tartrazine, which may cause allergic-type reactions or bronchial asthma in individuals sensitive to tartrazine. 

Bellacane Elixir—atropine, scopolamine HBr, hyoseyamine HBr or sulfate, phenobarbital, alcohol, tartrazine Bellacane SR Tablets—1-alkaloids of belladonna, phenobarbital, ergotamine tartrate Bellergal-S Tablets—1-alkaloids of belladonna, phenobarbital, ergotamine tartrate Butibel Elixir—belladonna extract, butabarbital sodium, alcohol, sucrose, saccharin Butibel Tablets—belladonna extract, butabarbitol Chardonna-2 Tablets—belladonna extract, phenobarbital Donnatal Elixir—atropine, scopolamine HBr, hyoseyamine HBr or sulfate, phenobarbital, alcohol, sucrose, saccharin... 

As an example, five different synthetic colorants (Tartrazine, Sunset Yellow, Ponceau 4R, Amaranth, and Brilliant Blue FCF) from drinks and candies were separated on a polyamide adsorbent at pH 4, eluted with an alkaline-ammonia solution. By another method, 13 synthetic food colorants were isolated from various foods using specific adsorption on wool. After elution with 10% ammonia solution and gentle warming, an absorption spectrum of the resulting colorant solution was recorded, compared to the reference spectra of pure colorants, and identified by linear regression analysis. ... 

Solid phase spectrophotometry proved to be an appropriate technique for the determination of colorants in foods dne to its simplicity, selectivity, reasonable cost, low detection limits, and use of conventional instrnmentation. This simple, sensitive, and inexpensive method allowed simnltaneons determinations of Snnset Yellow FCF (SY), Quinoline Yellow, and their nnsnlfonated derivatives [Sndan I (SUD) and Quinoline Yellow Spirit Soluble (QYSS)] in mixtnres. Mixtnres of food colorants containing Tartrazine, Sunset Yellow, Ponceau 4R, Amaranth, and Brilliant Blue were simultaneously analyzed with Vis spectrophotometry without previous chemical separation. ... 

Direct and derivative spectrophotometric and IP-RP-HPLC methods were applied to identify and determine synthetic dyes and follow their degradation processes. " The dyes considered were Tartrazine (E 102), Quinoline Yellow (E 104), Sunset Yellow (E 110), Carmosine (E 122), Amaranth (E 123), New Coccine (E 124), Patent Blue Violet (E 131), and Brillant Blue ECE (E 133). All are considered representative additives for soft drinks. 

Berzas Nevado, J.J. et ah. Simultaneous determination of tartrazine, riboflavine, curcumin and erythrosine by derivative spectrophotometry, Fresenius J. Anal. Chem., 350, 610, 1994. 

Cruces-Bianco, C., Garcia-Campana, A.M., and Ales-Barrero, F., Derivative spectrophotometric resolution of mixtures of the food colourants Tartrazine, Amaranth and Curcumin in a micellar medium, Talanta, 43, 1019, 1996. 

Berzas Nevado, J.J., Resolution of ternary mixtures of Tartrazine, Sunset Yellow and Ponceau 4R by derivative spectrophotometric ratio spectrum-zero crossing methods in commercial foods, Talanta, 46, 933, 1998. 

Capitan-Vallvey, L.F. et al.. Simultaneous determination of the colorants tartrazine, ponceau 4R and sunset yellow FCF in foodstuffs by solid phase spectrophotometry using partial least square multivariate calibration, Talanta, 47, 861, 1998. 

Sayar, S. and Ozdemir, Y., First-derivative spectrophotometric determination of Pon-cean 4R, Snnset YeUow and tartrazine in confectionery prodncts, Food Chem. 61, 367, 1998. 

French researchers provided an alternative to the tartrazine synthetic colorant (E 102), valorizing a phloridzine oxidation product (POP) generated as a by-product of the cider industry. Phloridzine is a polyphenol specific to apples and shows good antioxidant capacity. When apples are pressed to yield juice, phloridzine, oxygen, and polyphenoloxidase enzyme combine to form POP. This brilliant yellow natural colorant with nuances dependent on pH level can be incorporated easily into water-based foods such as beverages (juices, syrups) and confectionery creams because it is stable during production processes. Details about the specific formulations of these colorants are presented in Section 5.1. 

Azo dyes Allura Red AC, Amaranth, Azorubine, Brilliant Black BN, Brown FK, Brown HT, Lithol Rubine BK, Ponceau 4R, Red 2G, Sunset Yellow, Tartrazine Triarylmethane (triphenylmethane) dyes Brilliant Blue FCF, Fast green FCF, Green S, Patent Blue V... 

Several blends of colorants were established in order to prodnce desired hnes. To obtain orange color, one mnst mix the following colorants (parts per weight shown in parentheses) Allnra Red (25), Tartrazine (20), and Sunset Yellow (55). Food applications must take into account the fact that various colorants have different properties or can suffer chemical modifications in the specific conditions inherent in a food product. In such cases, the blend composition and color measurements must made in the product intended to be colored. ... 

Common additives in food are sulfur S(IV) oxospecies. Quinoline Yellow and Tartrazine show excellent stability toward S(IV) oxospecies while erythrosine. Red 2G, and Green S show good stability. - All other colorants show fair stability, except indigotine, which fades. In the presence of metabisulflte. Sunset Yellow FCF is degraded to a lemon yellow compound identified as l-(4 -sulfo-l-phenylhydrazo)-keto-3,3,4-trihydronaphtalene-4,6-disulfonic acid by NMR and FAB-MS techniques. ... 

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