Carminic add

Features Natural produces red-blue shades Regulatory FDA21CFR 73.100,73.1100,73.2087 EU E120 Properties Sol. in alkaline media insol. in water and alcohol up to 60% carminic add... 

Chem. Descrip. Hydrated aluminum chelate of carminic add, carmine... 

CAS 1390-654 EINECS/ELINCS 215-7244 Uses Colorant for foods (bakery mixes, confections, dairy prods.), cosmetics, and pharmaceuticals (tablet coatings, cough syrups), dry blends Features Natural produces pink to magenta red shades Regulatory FDA21CFR 73.100,73.1100,73.2087 EU E120 Properties Odorless water-sol. 50% carminic add Storage Keep in cool, dark place Carnapol 10 [Noveon]... 

Carminic add is a water-soluble and stable substance. The shade of colour in solution depends on pH and is orange at pH 3, red at pH 5.5 and purple at pH 7. The colour intensity is relatively low, therefore carminic add is used mainly as the red aluminium salt called carmine lake or crimson lake (containing about 50% of carminic acid), which is prepared from powdered insect bodies hydrolysed in diluted ammonia (or sodium carbonate) and by addition of alum. It is used as an intense red pigment for colouring some aperitifs (vermouths), meat products, specialty bakery and confectionery products, jams and dairy products. 

Carminic acid, a naturally occurring red pigment extracted from the cochineal insect, contains only carbon, hydrogen, and oxygen. It was commonly used as a dye in the first half of the nineteenth century. It is 53.66% C and 4.09% H by mass. A titration required 18.02 mL of0.0406 M NaOH to neutralize 0.3602 g carminic add. Assuming that there is only one acidic hydrogen per molecule, what is the molecular formula of carminic acid ... 

Procedure. Weigh out accurately from a weighing bottle about 0.2 g of the pure sodium carbonate into a 250 mL conical flask (Note 1), dissolve it in 50-75 mL of water, and add 2 drops of methyl orange indicator (Note 2) or preferably of methyl orange-indigo carmine indicator (Section 10.9), which gives a very much more satisfactory end point (Note 3). Rinse a clean burette three times with 5 mL portions of the acid fill the burette to a point 2-3 cm above the zero mark and open the stopcock momentarily, in order to fill the jet with liquid. Examine the jet to see that no air bubbles are enclosed. If there are, more liquid must be run out until the jet is completely filled. Re-fill, if necessary, to bring the level above the zero mark then slowly run out the liquid until the level is between the 0.0 and 0.5 mL marks. Read the position of the meniscus to 0.01 mL (Section 3.12). 

Procedure A with standard hydrochloric acid. Place the standardised (approx. 0.1 M) hydrochloric acid in the burette. Transfer 25 mL of the sodium hydroxide solution into a 250 mL conical flask with the aid of a pipette, dilute with a little water, add 1-2 drops of methyl orange or 3-4 drops of methyl orange-indigo carmine indicator, and titrate with the previously standardised hydrochloric acid. Repeat the titrations until duplicate determinations agree within 0.05 mL of each other. 

Bismuth Subcarbonate To 0.25 g add 20 ml DW, 0.05 ml indigo-carmine and then, as a single addition but with caution, 30 ml sulphuric acid. Titrate with indigo-carmine until a stable blue colour is produced. The volume of indigo carmine required is not more than that equivalent to 1 mg of N03 (0.4%). 

Calcium Acetate Dissolve 1.0 g in 10 ml DW, add 5 mg NaCl 0.05 ml indigo-carmine solution and with stirring 10 ml ofN2-free H2S04. The blue colour remains for at least 10 minutes. 

Sulphuric Acid Carefully add 5.0 ml to a mixture of 5 ml DW and 0.5 ml indigo carmine soln. and allow to stand for 1 minute. The colour of the solution is discharged. 

Indigo-Carmine Solution To a mixture of 10 ml of HC1 and 990 ml of a 20% w/v soln. of N2-free H2S04 in DW, add sufficient indigo-carmine (about 0.2 g) to produce a solution that complies with the following test Add 10 ml to a soln. of 1.0 mg of KNOs in 10 ml DW, rapidly add 20 ml HjSC and heat to boiling. The blue colour is just discharged in 1 minute. 

Bloom of Roses.—Powdered carmine of the best quality, two drachms, digested with strong ammonia four ounces, in a tightly stoppered bottle for two days, at the ordinary temperature of tho atmosphere. Then add rose water, one pint, and essence of rose, four ounces, After a week s repose, the upper stratum of dear liquid may be decanted from the subsident matter, and bottled. 

Place a 5 ml aliquot or less in a 50 ml volumetric flask and make to 5 ml volume with H2S04 (3.6M) if less than a 5 ml aliquot is used. The aliquot should contain 0-100 fig of boron. Add 20 ml of chilled H2S04 (18M) and swirl. Then, by pipet, add 20 ml of carminic acid (0.92 g in H2S04 (18M)). Make to volume with H2S04 (18M) and determine the absorbance in 1 cm cells in a spectrophotometer at 605 nm with a reagent blank in the reference cell. Compare with a standard curve containing 0-100 fig of boron. 

If the wool is intensely coloured, tin presence of artificial organic dye or of indigo carmine is probable. In this case the operation is nqn-.ited in an add or alkaline bath according to which gives the more intensely coloured wool the colouring matter is then extracted from the w(x> and identified by the methods describ d for artificial organic dyes (.see Chapter XV). 

Gutbier1 prepared pure brom-platinic add by repeatedly evaporating the pure chloride with concentrated hydrobromie acid on the water-bath and then treating it similarly three or four times with hydro-bromic acid containing bromine. The residue, on being taken up with dilute hydrobromie add, yields a deep carmine-red solution. 

Acidify a portion of the sample with dilute sulphuric acid, and add 1 ml of a 1% solution of indigo carmine. A deep blue colour is given by chlorates. 

Thallium diethyl 4 6-dinitro-2-aminophenoxide gives small, carmine-red plates, which have a metallic lustre and explode violently wlien moistened with ftnning nitric add. The salt darkens at 140° C., melts with decomposition at i59° C., and is moderately soluble in alcohol, acetone, or pyridine, slightly soluble in chloroform, ether, or toluene, and insoluble in carlx)n tetrachloride or light petroleum. 

Place 2.5 ml of acidic solution (-4 M H2SO4), containing not more than 25 pg of B, in a 25-ml standard flask. Add 5 drops of cone. HCl, 12.5 ml of cone. H2SO4, and carmine solution up to the mark. Mix the solution thoroughly and set aside for 1 h. Measure the absorbance of the solution at 650 nm, using a blank solution as reference. 

Dalb s Carminative. Take oils of caraway, fennel, and peppermint, each 10 drops rub them up with 10 ounces white 8Ug and 5 ounces carbonate or lump magnesia, then add 1 drachms sal-tartar and 2 ounces laudanum. Mix with pints of wa-... 

Mn(CN)5NO] " is best prepared as the purple, crystalline, diamagnetic potassium salt K3[Mn(CN)5N0] 2H20 by adding hydroxylamine to an aqueous solution of a manganese(II) salt and an excess of KCN. Yields from the reaction of NO with aqueous solutions of [Mn(CN)g] " are usually poor. Treatment of the potassium salt with a non-oxidizing add gives carmine-red H3[Mn(CN)5NO]. 

Place fixed tubules in a watch glass containing 1% aceto-carmine (about 10 drops) for 15 min. Transfer small pieces of stained tubules onto clean siliconized slides, add a drop of 45% acetic acid over the tubules, cover with zero thinness, 22-mm-size cover glass, place the slide centrally within a pad of bibulous paper, and press firmly with the thumb. Seal the cover glass to the slide with Kronig s cement. 

Carminic acid and kermesic add can be regarded as more highly substituted derivatives of alizarin. In 1858, carminic acid was isolated in pure form, and in 1916, its structure was determined by Otto Dimroth (1872-1940). [55] The dyestuff, carminic acid, is distinguished from kermesic acid by a C-glucosyl residue in the former (Fig. 2.22). 

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