Tartrazine colouring

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. 

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. 

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. 

A number of commercially available yellow monoazo pigment lakes are based on a pyrazolone sulfonic acid derivative as a coupling component. An example is the aluminum tartrazine lake, listed in the Colour Index as Pigment Yellow 100,... 

Both the European Union and the FDA have pubhshed lists that are subject to regular review. The greatest concern has been expressed over the use of azodye colours as certain individuals can demonstrate an allergic reaction to some of these. Allergic reactions have been reported most frequently for sunset yellow (E110, FD C yellow no. 6) and tartrazine (E102, FD C yellow no. 5). 

Purity criteria of colours for use in foodstuff are regulated in the EU under Directive 95/45/EC [4], According to the legislation food dyes that are placed on the market, must meet special purity requirements An example for C.I. Food Yellow 4 (tartrazine) is shown here ... 

Colouring agents are added to make food and drink look more appealing. Some are synthetic, for example tartrazine and erythrosine, while others are natural, for example carotene and annatto. 

Urticaria due to intake of tartrazine is more widely accepted as an adverse effect and has been demonstrated in a number of studies. During this reaction substances such as histamine are released into the blood which cause the symptoms of red weals on the skin and itching. A number of other food colours and other types of food additives can also cause urticaria and there may be cross-reactivity between colours such as eryth-rosine and sunset yellow. A challenge of patients whose urticaria had improved on a colour-free diet with 0.15 mg of tartrazine, resulted in three out of thirteen developing urticaria within three hours of exposure."... 

Asthma may also be a symptom of hypersensitivity to tartrazine and one study showed that ii per cent of asthmatics reacted to an orange drink containing colouring agents."... 

T FOOD YELLOW 4 FOOD YELLOW 5 FOOD YELLOW NO. 4 HD TARTRAZINE HD TARTRAZINE SUPRA HEXACERT YELLOW NO. 5 HEXACOL TARTRAZINE HIDAZID TARTRAZINE HISPACID FAST YELLOW T HYDRAZINE YELLOW HYDROXINE YELLOW L K.AKO TARTRAZINE KAYAKU FOOD COLOUR YELLOW NO. 4 KAYAKU TARTRAZINE KCA FOODCOL TARTRAZINE PF KCA TARTRAZINE PF KITON YELLOW T LAKE YELLOW LEMON YELLOW A LEMON YELLOW A GEIGY L-GELB 2 MAPLE TARTRAZOL YELLOW MITSUI TARTRAZINE NAPHTOCARD YELLOW O NEKLACID YELLOW T OXANAL YELLOW T SAN-EI TARTRAZINE SCHULTZ NO. 737 SUGAI TARTRAZINE TARTAR YELLOW FS TARTAR YELLOW N TARTAR YELLOW PF TARTAR YELLOW S TARTRAN YELLOW TARTRAPHENINE... 

Teraoka R, Matsuda Y, Sugimoto I. Quantitative design for photostabilization of nifedipine by using titanium dioxide and/or tartrazine as colourants in model film coating systems. J Pharm Pharmacol 1988 41 293-297. 

Tartrazine, 4,5-dihydro-5-oxo-l-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-l//-pyrazole-3-carboxylic acid trisodium salt was discovered by Ziegler in 1884 and is used as a dye for wool and silk. It is used as a colour additive in foods, drugs and cosmetics, and is an adsorption-elution indicator for chloride estimations in biochemistry (B-76MI40404). 

Lancaster FE, Lawrence JF. Determination of benzidine in the food colours tartrazine and sunset yellow FCF, by reduction and derivatization followed by high-performance liquid chromatography. Food Addit Contam 1999 16(9) 381-90. 

Flavazin L has already been described as a textile dye derived from pyrazolone. Tartrazine 5 is one of the few synthetic dyes which are approved for colouring foodstuffs and cosmetics. The yellow compound, which is the trisodium salt, is produced by coupling 2,4-dihydro-3//-pyrazol-3-ones with diazo-tized sulfanilic acid. The required pyrazole is accessible from diethyl 2-oxobutanedioate and 4-hydrazinobenzene-1-sulfonic acid. 

Phenylbutazone has been utilised for some time in the treatment of severe arthritis, which, incidentally, afflicted such notables as Casanova, Goethe, and Luther. Leflunomide is used in the therapy of autoimmune diseases, such as active rheumatoid arthritis. Celecoxib is the first to market of a number of selective cycloxygenase 2 (COX 2) inhibitors which show great promise as anti-inflammatory and analgetic agents, without the undesirable side effects associated with other nonsteroidal anti-inflammatories. There are many pyrazole dyestuffs - the food colourant tartrazine is one such substance. 

In pharmacy, the dyes used are azo dyes, quinoline dyes, tri-phenylmethane and xanthine dyes. They are not recommended in children because many colouring agents, mainly synthetic dyes, have been associated with hypersensitivity and other adverse reactions (gastrointestinal intolerance, dermatological reactions and carcinogenic concerns). Approximately 2-20% of people with asthma are sensitive to aspirin. Cross-reactions to azo dyes such as tartrazine produce similar effects. They have occurred in patients both with and without a history... 

Beetroot red, betanin Elderberry colour Anthocyanins Amaranth Tartrazine... 

Tartrazine, 2% petrolatum. Food colouring. Non-immunological reactions (Grater 1976), type-IV reaction (Roeleveld and Ketel 1976)... 

Legislation on colouring agents for medicines follows Food legislation [63] Azo dyes - especially tartrazine — are suspected of adverse reactions. The latest evaluation by the European Food Safety Agency (EFSA) resulted in 2009 in a continuation of the allowance [64]. Nevertheless the UK Foods Standards Agency advices that avoiding of colourants in the diet of hyperactive children may have a beneflcial effect. 

Complexation has frequently been correlated with the hydrophobic character of one (or both) of the interacting ions [273-279]. Details of the interaction between a series of dyes and alkyltrimethylammonium bromides have been published [277], The structure of the dyes used, tartrazine (XXVI) amaranth (XXVII) carmoisine (XXVIII) and erythrosine (XXIX) are shown below. These are all important colours used in the food, drug and cosmetic industries. Phase separation diagrams were constructed to indicate the relationship between surfactant concentration and the anisotropic solution-coacervate boundary. Differences between the interactions of a hydrophilic dye, tartrazine and amaranth, carmoisine and erythrosine which have both hydrophobic and hydrophilic moieties were exhibited. Tartrazine appears to behave like a simple electrolyte interacting simply with the charged groups at the micellar surfaces while the other dyes complexed and were solubilized as a complex in addition to interacting with the micelle surface [277]. These dyes also induced the formation... 

Linctus of Methadone Hydrochloride, B.P.C, Contains 0 057 per cent w/v of methadone hydrochloride in a base of glycerin and syrup of tolu, coloured with tartrazine. 

The official method of assay is to dilute 5 ml with 100 ml of water, acidified with 01 ml of dilute sulphuric acid, and complete by method (v), titrating with 0-2M KIO3 and calculating the percentage as Zn. 1 ml 0-2M = 0 002179 g Zn. It can also be assayed by method (viii) (a) using 10 ml since the preparation contains tartrazine the colour change at the end-point is from red to green. 

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