Sunset yellow colouring

On venturing into the bathroom and inside the medicine cabinet, I discovered to my surprise a cold cure containing sunset yellow (colour). However, pride of place in the list of additive-laden products went to the vitamin pills which contained the following ... 

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). 

There are a large number of other published procedures for the separation of a number of sweeteners and preservatives at one time these are all based on reverse-phase HPLC. Perhaps one of the most startling is the method published by Williams (1986). This uses a small particle size (3 xm) C8 column and allows the separation of a range of colours, sweeteners and preservatives in less than 5 min. The materials separated were amaranth, quinoline yellow, quinine sulphate, sunset yellow, caffeine, aspartame, saccharin, vanillin, sorbic acid, benzoic acid and green S. 

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."... 

Other colourants in use are sunset yellow (Eiio), another synthetic azo dye, and caramel. Caramel colours are manufactured from sugars and are very widely used. This food colour has caused some concern due to effects in experimental animals, for example the reduction in the number of white blood cells in rats. This may be due to the effects of contaminants at the high doses given which may be enhanced by a reduced intake of vitamin B6 in the diet. Annatto and beta carotene are naturally occurring colourants, but in one study 26 per cent of patients with chronic urticaria were shown to react to annatto. 

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. 

Colours. The synthetic colours Ponceau 4R and Sunset Yellow FCF are used in some Danish types of dried sausages. Ponceau 4R is permitted up to 40 ppm and Sunset Yellow up to 50 ppm (Positivlisten,... 

The light of the flare is rather pale and the smoke lines are yellow, but we don t sense the colours, merely the contrast between the brilliancies rather like a black and white drawing. Another of the extremes may be the "Flower in the Sunset", which is a smoke flower with red stars of high brilliancy as the pistils. In this case only the red of the pistils meikes a deep impression, and any coloured smoke red, yellow, green, blue or violet can serve as petals because it has only an auxiliary effect against the pistils. 

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