Soluble azo dyes

OIL SOLUBLE AZO DYES The oil soluble, water-iasoluble, azo dyes dissolve ia oils, fats, waxes, etc. Generally, yellow, orange, red, and brown oil colors are azo stmctures and greens, blues, and violets are primarily anthraquiaones (see Dyes, anthraquinone). Blacks are usually nigrosiaes and iaduhnes of the aziae type (see Azinedyes). An example is Oil Red [85-83-6] (127) (Cl Solvent Red 24 Cl 26105). Uses iaclude the coloring of hydrocarbons, waxes, oils, candles, etc. 

SPIRIT SOLUBLE AZO DYES Spirit-soluble azo dyes dissolve ia polar solvents, such as alcohol and acetone, and find appHcation ia the... 

The soluble azo dyes contain one or more sulfonic acid groups. Their degree of water solubiUty is determined by the number of sulfonic groups present and their position in the molecule. FD C Red No. 40 (5) and D C Orange No. 4 (16) belong in this class. 

G. M. Shaul, R. J. Lieberman, C. R. Dempsey, and K. A. Dostol, "TreatabiUty of Water Soluble Azo Dyes by the Activated Sludge Process,"... 

Chen H, Xu H, Heinze TM (2009) Decolorization of water and oil-soluble azo dyes by Lactobacillus acidophilis fermentum. J Ind Microbiol Biotechnol 36 1459-1466... 

Shaul GM, Holdsworth TJ, Dempsey CR, Dostal KA (1991) Fate of water-soluble azo dyes in the activated sludge process. Chemosphere 22 107-119... 

Sulfonated azo dyes are widely used in different industries [16]. Some structure of sulfonated and unsulfonated azo dyes is shown in Fig. 1. These water-soluble azo dyes will enter the environment generally with wastewater discharge. Also, these sulfonated and unsulfonated azo dyes have a negative aesthetic effect on the wastewater, and some of these compounds and biodegraded products are also toxic, carcinogenic, and mutagenic [17]. There exists clear evidence that sulfonated azo dyes show decreased or no mutagenic effect compared to unsulfonated azo dyes... 

Oil-soluble azo dyes, 9 420-421 Oil soluble sulfonates, 23 530 recent developments in, 23 534 Oil-water separation, 22 68... 

Spiramycin complex, 15 290, 29 It, 300 Spirit soluble azo dyes, 9 421 Spirit thermometers, 24 464... 

With the introduction of synthetic dyes, attempts were made to prepare pigments from them by methods based on those that had been used with the natural dyes. Many soluble azo dyes can be rendered insoluble by precipitating them as the salts of heavy metals in the presence of so-called alumina hydrate. This method will be treated in detail later and here only the making of pigments from acid dyes and basic dyes will be mentioned. The use of alumina hydrate as a basic substrate for making pigments from dyes is now, however, of diminishing commercial importance. 

A very noticeable feature has been the use of a wider range of heterocyclic coupling components than in water-soluble azo dyes. An early example of this trend was Cl Disperse Yellow 5 (4.74), which used 4-hydroxy-1-methylcarbostyril as coupling component. It was in... 

Shaul, G.M., Lieberman, R.J., Dempsey, C.R., and Dostal, K.A. Treatability of water soluble azo dyes by the activated sludge process, in Proceedings of the Industrial Wastes Symposium, 59" Water Pollution Control Conference, October 1986. 

Shaul, G., Dempsey, C., and Dostal, K., Fate of Water Soluble Azo Dyes in the Activated Sludge Process, EPA/600/S2-88/030, U.S. Environmental Protection Agency, Research and Development Office, Washington, D.C., 1988. 

In accordance with chemical aspects, the most important alcohol- and ester-soluble azo dyes can be divided into three groups. 

Fat- and oil-soluble dyes are also soluble in waxes, resins, lacquers, hydrocarbons, halogenated hydrocarbons, ethers, and alcohols, but not in water. It is not possible to differentiate clearly between them and the alcohol- and ester-soluble dyes. With the exception of blue anthraquinone derivatives, fat- and oil-soluble dyes are azo dyes, generally based on simple components. According to their degree of solubility they usually contain hydroxyl and/or amino groups, but not sulfonic acid and carboxylic acid groups. Examples of fat- and oil-soluble azo dyes are C.I. 

By far the most predominant metabolic pathway for water-soluble azo dyes is cleavage of the azo linkage by azoreductase of the liver and extrahepatic tissue or by intestinal microflora in the body [25,26], Oxidative metabolism occurs for lipid-soluble dyes, e.g., solvent dyes. Three oxidation pathways are known for such dyes (1) C-(ring-)hydroxylation, (2) A-hydroxylation at a primary or secondary amino group or (3) by stepwise oxidation of the methyl groups of dimethylamino compounds (demethylation). All three oxidative degradation ways leave the azo bond intact. For further details of the mechanisms, see [27,28],... 

The introduction of polar groups, such as the sulfonic acid or carboxyl group, increases the solubility sufficiently to yield rather useful indicators. We shall see in Chapter Ten that these water-soluble azo dyes are especially valuable because their salt error is negligible. 

Polymeric quaternary ammonium surfactants made from w-dodecyl bromide and poly(2-vinylpyridine) are better solubilizers for oil-soluble azo dyes and for n-decanol than monomeric quaternary cationics with similar (monomeric) structures (Tokiwa, 1963 Inoue, 1964). Solubilization of n-decanol in the polycationics increased as the alkyl chain content increased to a maximum at 24% alkyl content and resulted, at high decanol content, in intermolecular aggregation of the poly cationic molecules (Inoue, 1964). 

Fate of Water Soluble Azo Dyes in the Activated Sludge Process... 

The ethoxytates having only two ethylene oxide units, for example, nonylphenol diglycol in the form of its O-sulphate has been employed as a surfactant in the aqueous suspension of weakly soluble azo dyes used for dyeing hydrophobic polyester fibres (ref. 30). 

M. Tachibana, T. Imamura, M. Saito, and K. Kina, Rapid Determination of Copper in Serum by Flow Injection Analysis with Water Soluble Azo Dye [in Japanese]. Bunseki Kagaku, 32 (1983) 776. 

BON n. Acronym for betaoxy-naphthoic acid, which can be coupled with a variety of amine compounds to form a soluble azo dye, which is then precipitated by any of several metals to form Bon reds or maroons. 

To study quantitatively the kinetics of lipid oxidation and antioxidation, a standard way of controlling and measuring the rate of free radical initiation is to use thermally labile azo compounds. These artificial initiators generate radicals at a reproducible, well-established and constant rate. In the presence of initiators such as a,a-azobisisobutyronitrile (AIBN) or benzoyl peroxide, the overriding initiation can be directly related to the rate of production of the initiator radical. Also, by using either water-soluble or lipid-soluble azo dyes, these compounds can initiate radicals at known specific micro-environments. 

Schwack, W., Pelhssier, E. (2009) Determination of unauthorised fat-soluble azo dyes in spices by HPTLC. CAMAG Bibliography Service CBS, 103,13-15. 

Determination of Banned Fat-Soluble Azo Dyes in Spices ON Caffeine-Impregnated Silica Gel Plates... 

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