Classification of colorants

Hair Coloring Regulation Issues. In the United States the classification of color additives is complex. Under the Federal Food, Dmg and Cosmetic Act, all cosmetic colors must be the subject of an approved color additive petition to the Food and Dmg Administration there is an exception for coal-tar colorants used to color hair. Based on the composition of these colorants, FDA can require a certification on each manufactured batch of colorant to assure conformance with the approved specifications. In the early 1990s FDA has required certification only for synthetically derived coal-tar type colors. Many of the approved color additives, both certified and noncertified, are restricted ia their potential use. These restrictions can be found ia the color additive regulations ia the Code of Federal Regulations at 21 CFR 73 and 74. 

This edition and the completely revised five-volume Third Edition (1971) established the Colour Index as the leading reference work for the classification of colorants, fully justifying the cognomen International belatedly added in 1987. The fourth revision (1992) of the Third Edition consisted of nine volumes. The original data on technical properties (Volumes 1-3) and chemical constitution (Volume 4) was supplemented (Volumes 6-9) at roughly five-year intervals. 

Recalling the above-mentioned classification of color reactions, it is clear that in the Griess reaction atoms from the analyte are incorporated into the colored product. This leads to a higher degree of specificity compared with oxidation/ reduction reactions where only electrons (and no atoms) are transferred. 

Toward the Classification of Colorants in Archaeological Textiles of Eastern North America... 

In the United States the classification of color additives is complex. Under the Federal Food, Drug and Cosmetic Act, all cosmetic colors must be the subject of an approved... 

Modification of WitFs Terms and Classification of Colored Organic Compounds... 

What is the difference between a pigment and a dye According to the principles of color technology, pigments are applied to a surface with the use of a vehicle that allows it to be spread dyes need no such binder and can inhere in the substrate directly. Thus, any substance may be classified as a pigment or a dye depending upon how it is applied to the substrate, and both should be discussed under the more general classification of colorants . 

The range of colors covers all hue classification groups except a tme red. As a rule, the hues are dull compared with other dye classes. Black is the most important, followed by blues, oHves, and browns (see Dyes and dye intermediates). 

Ciolino, L.A., Determination and classification of added caramel color in adulterated acerola juice formulations, J. Agric. Food Chem., 48, 1746, 1998. 

Figure 2.1 Classification of electrochemical electron transfer reaction on metal electrodes. (See color insert.)...

Mateo, R. and Bosch-Reig, F. (1998). Classification of Spanish unifloral honeys by discriminant analysis of electrical conductivity, color, water content, sugars, and pH. /. Agric. Food Chem. 46, 393 00. 

Table 2 Classification of synthetic organic colorants by chromophores... 

The process of classification is typically based on systematically arranging entities on the basis of their similarities and differences. A bowl of fruit can be systematically arranged to have apples on one side and bananas on the other. Chemical elements can be systematically arranged into distinct families on the basis of their atomic structures. Classification of this sort is relatively easy and can be grounded on any number of relatively distinctive parameters or combinations of parameters, including color, size, shape, structure, taste, and so forth. We have already noted that psychiatric disorders are best characterized as open concepts. In open psychiatric concepts, overt, objective, and distinctive parameters are often less apparent, making their classification considerably more difficult. 

Inorganic pigments, 29 375-417 black pigments, 29 408-410 chemical properties of, 29 377-378 classification of, 29 402 colored pigments, 29 397-408 crystal structure of, 29 377-378 durability of, 29 382-384 environmental aspects of, 29 413-415 lead- and cadmium-containing, 29 414-415... 

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