Dyes, classification reactive

Contrary to other dye groups reactive dyes are characterized by known chromo-phore systems, as described in this book, and by bearing various reactive moeties in their molecules. Thus, dye systems which are used to form reactive dyes comprise all industrial important groups of dyes. Consequently, the classification in this section is primarily according to the various reactive groups. 

Azo dyes are classified according to a color index system based on usage and chemical constituents. These are subdivided into monoazo, disazo, trisazo, and polyazo derivatives with a specific assigned range of color index number. Another classification system involves dividing dyes into dyeing classes such as acid, basic, disperse, direct, mordant, and reactive dyes. Azo compounds are used extensively as dyes to color varnishes, paper, fabrics, inks, paints, plastics, and cosmetics. They are used in color photography. 

Mishra and Tripathy (1993) proposed a simplified classification as follows anionic (direct, acid, and reactive dyes), cationic (basic) dyes, and nonionic (disperse) dyes. There are many structural... 

There are, of course, many varieties in each of these chemical classifications, so that the result is hundreds of individual dyes each with its own specific characteristics for hue and use on substrates. Dyers have arranged this very complex and large group of chemical products into ten categories arranged by the method of application to the fiber or substrate acid dyes, azoic dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, vat dyes, and mordant dyes. It is in these categories that dyestuffs are discussed in the trade. 

The color index (Cl) number, developed by the society of dyers and colorists, is used for dye classification. Once the chemical structure of a dye is known, a fivedigit Cl number is assigned to it. The first word is the dye classification and the second word is the hue or shade of the dye. For example, Cl Acid Yellow 36 (Cl 13065) is a yellow dye of the acid type. Additionally, a dye mixture may consist of several dyes for example, Navy 106 is composed of three reactive azo dyes remazol black B (Reactive Black 5), Remazol Red RB (Reactive Red 198), and Remazol Golden Yellow 3. 

It has been shown in this chapter that the DNA-modified electrodes (electrochemical DNA biosensors) already represent very effective and, at the same time, simple, fast, inexpensive, miniaturized, and mass-producible analytical devices for evaluation and classification of modes of genotoxic effects of individual xenobiotic compounds (e.g., chemical carcinogens, pesticides, dmgs, dyes, or reactive radical species), as well as for prescreening of new drugs and newly synthesized chemicals. Moreover, the evaluation of DNA protection capacity of various natural and synthetic chemical substances (antioxidants) is also possible using the detection of DNA damage caused by prooxidants. 

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