Indigotin indigo blue

The compound 5) was converted into its sodium salt with the appropriate quantity of sodium hydroxide and this proved to be stable, soluble in water, substantive to cellulose, and capable of being oxidized, on the fibre, to Indigotin (Indigo Blue). The anthraquinone dyes react similarly, an example being solubilized Indanthrone, (36). 

Indigotin — Indigo-blue—CuHioNjOj — constitutes the greater part of the commercial indigo. It does not exist preformed in the plants from which it is obtained, whose juice is naturally colorless, but is produced by decomposition of a glucosid contained in them (see Indican, p. 451). 

FD C Blue No. 2 " (2) Indigotine Indigo Carmine Cl Food [860-22-0] 73015 nylon sutures for use in general... 

Quantitative Determination of Indigo Blue (Indigotin). — This test is to be carried out as detailed under Synthetic Indigo. 

Indigotine, indigo carmine, FD C blue 2 132 73015 I Disodium-3,3 -dioxo-2,2 -bi-indolylidene-5,5 -disulfonate C16H8N2Na2OgS2 466.36 610... 

Synonyms 2-(l,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-lH-indole-5-sulfonic acid disodium salt disodium 5,5 -indigotin disulfonate E132 FD C blue 2 indigotine sodium indigotin disulfonate soluble indigo blue. 

Indigotin is insoluble in most of the usual solvents. It dissolves in aniline, chloroform, nitrobenzene, phenol, paraffin, petroleum, naphthalene, and in certain fatty oils. The solutions have not all the same colour for example, the aniline and chloroform solutions have a deep indigo-blue colour, while the solution in paraffin has the purple-red colour of indigo vapour, a behaviour somewhat similar to that of iodine. 

Dinitro- and diamido-indigotin have been prepared from dinitro-isatin [33]. (Compare the Synthesis of Indigo Blue, p. 231.)i... 

Indoxyl readily reacts with atmospheric oxygen to form the insoluble pigment Indigotin, also known as Indigo Blue ... 

Indigotin, indigo [2,2 -biindolinylidene-3,3 -dione, C. I. natural blue 1]. 

CAS 482-89-3 EINECS/ELINCS 207-586-9 Synonyms 1 H,1 H-[2,2 -Bindolylidene-3,3 -dione Cl 73000 D C Blue No. 6 2-(1,3-Dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one Indigotin Pigment blue 66 Synthetic indigo blue Vat blue 1... 

Indigo carmine (El 32) Indigotine Indigoid Blue Soluble Solid and oral dosage forms... 

E132 indigotine, indigo carmine FD C Blue No 2 Triphenylmethane Green-blue... 

Indigo (blue) Indigotin, C16H10N2O2 One of the oldest coloring materials known Used in painting Roman war shields... 

Di-Na salt [860-22-0]. Indigo carmine. Soluble indigo blue. C.I. Acid blue 74. C.I. Food blue I. Amacid brilliant blue. Carmine blue. Indigotine. C.I. Pigment blue 63. C.I. 

Indigo is considered as one of the most important dyes. Its preparations are usually analysed by HPLC with UV-Vis [46,60] or APCI MS detection. [61,62] Separation of the colouring components of indigo extracted with DMSO is usually performed with the use of a Cl 8 column. Spectrophotometric detection of blue indigotin is performed at 617 nm, red indirubin at 540 nm, and brown isoindigo at 365 and 490 nm. As mobile phases, mixtures of methanol or acetonitrile and water with the addition of TFA or formic acid are used to ensure compatibility with the requirements of the APCI source. 

The optimized RPLC UV-Vis ESI MS method for all typical blue colourants (indi-goids, hematein, tannins, anthocyanins and selected flavonoids) was used for the identification of dyes extracted from a thread taken from an Italian tapestry of unknown origin from the collection of the National Museum in Warsaw (Poland). It was found that to obtain the red-blue colour of the fibre a mixture of dyestuffs was probably used. The presence of indigotin, tannic and ellagic acid (at m/z 301, NI), as well as carminic acid, suggested the use of indigo and cochineal. Reseda luteola could also have been used due to the presence of luteolin and apigenin. 

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