Basic dyes dissolving

Cyclohexanoae is miscible with methanol, ethanol, acetone, benzene, / -hexane, nitrobenzene, diethyl ether, naphtha, xylene, ethylene glycol, isoamyl acetate, diethylamine, and most organic solvents. This ketone dissolves cellulose nitrate, acetate, and ethers, vinyl resias, raw mbber, waxes, fats, shellac, basic dyes, oils, latex, bitumea, kaure, elemi, and many other organic compounds. 

The corresponding copper ferrocyanide salts of basic dyes are obtained by treating potassium ferrocyanide K4[Fe(CN)6] with sodium sulfite. Dissolved to-... 

The more popular method to control leveling is to use cationic products that act as colorless dyes competing with the colored cationic dyes for the fiber sites. If amounts of colored modified basic dye and colorless modified basic dye equal to the saturation value of (he fiber are uniformly dissolved in the dyebalh. then level dyeing behavior is promoted. 

Food samples are dissolved in water and acidified with acetic acid (135,157). According to Gilhooley et al. (157), excess methanol has to be removed from solutions before passing through polyamide because it impairs the adsorption of the dyes by the polyamide. The solution is stirred with polyamide powder, and the slurry is transferred to a microcolumn or it is passed through the column of polyamide. The latter is recommended since dyes are adsorbed as a narrow band at the top of the column. The column is washed with hot water to remove sugars, acids, and flavoring materials and with acetone to remove basic dyes, water-soluble carotenoids, and some antho-cyanins. The adsorbed acid dyes are eluted with methanol sodium hydroxide (164,172,175), with methanol ammonia (176), or with acetone ammonia (157). Acetone ammonia is preferred because it can be removed in a water bath and, on addition of acid, no salts are formed that interfere with the adsorption of the dyes by the polyamide (157). The eluate is evaporated to dryness and redissolved in the HPLC mobile phase (156). 

The outstanding characteristic of the basic dyes is the brilliance and intensity of their colours. Some of the shades are of such clarity of hue that no other class can compare with them. The intensity is illustrated by a comparison of the dyeing properties of magenta, which is a basic dye, and acid magenta, which has the same molecular structure but has been converted into an acid dye by sulphonation. Whilst 5 per cent of the latter is required to produce a full shade on wool, only 2 to 3 per cent of basic magenta is necessary. The basic dyes are readily soluble in alcohol or methylated spirit. They are not, as a rule, so easily dissolved in water and, unless care... 

Some basic dyes form ion-associates with Bib that can be used in sensitive methods for determining bismuth. Extractable compounds are formed with Rhodamine B, Butylrhodamine B, and Rhodamine 6G (benzene, e = 1.1-10 ) [52], and with the azo dye (formula 10.1, e = 9.2-10 ) [53]. The ion-associate of the bromide complex of Bi with Rhodamine 6G has been floated with DIPE and then dissolved in ethanol (e =1.5-10 ) [54]. 

High sensitivity characterizes methods based on the formation of sparingly water-soluble ion-associates of germanomolybdate (Mo-Ge) with basic dyes. The compound with Rhodamine B can be floated and then dissolved in ethanol. The molar absorptivity is -3.7-10 [40]. The Mo-Ge compounds with Methylene Blue, Crystal Violet or Malachite Green, can be centrifuged and then dissolved in acetone. The molar absorptivities are 4.5-10, 4.2-10, and 6.2-10, respectively [41 3]. The ion associate formed by the Mo-Ge anion (reduced with ascorbic acid) with Chrompyrazole II has been floated by shaking with toluene, then dissolved in acetone [44]. 

This very sensitive flotation-spectrophotometric method is based on the ion associate formed by the anionic chlorostannate(II) complex of platinum(II) with the xanthene basic dye Rhodamine 6G (formula 4.30) [41]. When the aqueous phase is shaken with DIPE, the sparingly soluble compound collects on the wall of the separating funnel. The solid associate is washed, dissolved in acetone, and its absorbance is measured. 

The optimum SnCh concentration during flotation is 0.01-0.02 M. At higher SnCh concentration, the absorbance of the blank increases. The excess of basic dye should be at least 50-fold with respect to Rh. The precipitate in the separating funnel is washed with 2 M HCl, then dissolved in acetone. This solution is the basis of a very sensitive and precise method for spectrophotometric determination of rhodium [43]. The molar absorptivity is 4.0-10 (a = 3.9) at 530 nm. 

Sensitive methods for determining silicon are based on the formation of molybdosilicate ion-associates with certain basic dyes. The ion-associate with Crystal Violet (formula 4.26) can be extracted with a 3 2 mixture of cyclohexanol and isoamyl alcohol [36]. The sparingly soluble compound is centrifuged and then dissolved in acetone (e = 4.2-10 at 590 nm) [37]. 

The ion-associate with Rhodamine B is separated by flotation with DIPE and dissolved in ethanol (e- 5.0-10 at 555 nm) [38]. Other basic dyes have also been proposed, namely... 

Sensitive extraction-spectrophotometric methods are based on the extractable (into CHCI3, 1,2-diehloroethane, benzene, or toluene) ion-associates of basic dyes and anionic Ag complexes with cyanide [35,36], iodide [37,38], and bromide [39]. In these methods, use has been made of such dyes as Crystal Violet [35,39], Brilliant Green [38,39], Malachite Green [39], Methylene Blue [36], and Nile Blue A [37]. In some of these methods the molar absorptivities are elose to MO [36,39]. A flotation method has been proposed, based on the addition compound [R6G ][Ag(SCN )2] [R6G ][SCN ] which is formed by silver ions (at pH 2-5) in the presence of thiocyanate and Rhodamine 6G (flotation with DIPE, the precipitated compound is washed and dissolved in acetone, e = 1.5-10 ) [40]. The complex Ag(CN)2 , associated with Crystal Violet, has been utilized in another flotation-spectrophotometric method of determining silver [41]. Silver has been determined also in a system comprising thiocyanate and Rhodamine B, as an aqueous pseudo-solution, in the presence of poly(vinyl alcohol) [42]. 

The methods of determining Te with the use of basic dyes are very sensitive. The tellurium bromide complex has been extracted as the ion-associate with Butylrhodamine B [44,45] or Victoria Blue 4R (e = 8.0-10 ) [46]. The halide complexes give also ion-associates, extractable into toluene (e = 3.75-10 ) with Violet Red [47 9]. The TeBr associate with Rhodamine 6G can be floated with benzene, and the separated compound is then dissolved in a mixture of benzene with ethanol (e = 1.7-10 ) [50]. The ion-associate of the iodide complex of Te(IV) with Nile Blue A has been floated with cyclohexane, and the separated compound dissolved in methanol (e = 1.4-10 at 640 nm) [51]. High sensitivity has... 

High sensitivity characterizes the methods based on ion-associates formed by anionic complexes of V(V) with basic dyes. The Brilliant Green method has been described above [33]. The vanadium complex with PAR associated with Crystal Violet is extracted into a mixture of benzene with MIBK (3-f2) (e = l.l lO ) [51]. In a proposed flotation-spectrophotometric method, the V complex with 3,5-dinitropyrocatechol, associated with Rhodamine B, is separated by shaking the solution with cyclohexane the separated compound is washed and dissolved in acetone (e = 2.1-10 at 555 nm) [52], A similar sensitivity is achieved in the method using 5,7-dichloro-oxine and Rhodamine 6G [53]. Another flotation-spectrophotometric method for determining V has been based on 3,5-dinitrosalicylic acid and Rhodamine B [54]. 

The ion-associate (the anionic Zr-Picramine-epsilon complex and the basic dye Ethyl Rhodamine B) is floated, and dissolved in acetone (e = 3.2-10 ) [80]. 

Cyclohexyl acetate [622-45-7] is very slightly miscible with water, but completely miscible with common organic solvents. Its solvency properties are comparable to those of amyl acetate. Cyclohexyl acetate dissolves oils, fats, resins, waxes, cellulose nitrate, cellulose tripropionate and acetobutyrate, alkyd resins, unsaturated and saturated polyester resins, phenolic resins and aminoplasts, poIy(vinyI chloride), vinyl chloride copolymers, poly(vinyl acetate), poly(vinyl ethers), epoxy resins, and acrylic resins, basic dyes, blown oils, crude rubber, metallic soaps, shellac, and bitumen. 

Ethyl lactate is a colorless and olmost odorless liquid, which, upon evaporotion, will sometimes develop a disagreeable odor. This is owing to the iactides, or inner anhydrides, contained in the lactic acid mode by fermentation. It is miscible with water, alcohols, ketones, esters, hydrocarbons and oils. Ethyl lactate will dissolve cellulose acetate ond nitrate ond many of the ethers of Cellulose. It is also a solvent for basic dyes, alkyd resins, kauri, manila, pontionac, rosin, shellac and vinyl resins. Ethyl lactate has high solvent power and equally high tolerance far nonsolvents and diluents. These exceptional properties are accounted for by the existence of both an alcohol and an ester group in its molecule. 

Hair coloring preparations are classified into four types temporary dye, metallic (progressive) dye, ionic (acidic and basic) dye, and permanent (oxidative) dye. The oxidative dye is the most popular hair dye because of its color durability and easy application. Oxidative dyes are usually composed of dye compounds (A) solution and a hydrogen peroxide (B) solution. Both solutions are creamy. The A solution also contains strong alkaline ammonia to open hair cuticles. Dye components polymerize into indophe-nol-like trimers, etc., in the presence of hydrogen peroxide, primarily in the cortex of the hair. Hairs 3 cm long dyed by oxidative dyes of 34 brands are dissolved in the solution of methanol plus 3 mol 1 ... 

Basic dyes are water-soluble in the form of their salts and are used for colouring paper, leather, cellulose- and polyacrylonitrile fibres. The free bases dissolve in many organic solvents and find application similar to that of the solvent dyes. Basic dyes can function as pigments in lacquer form. Mixtures of basic dyes are usually responsible for brown, green and black tones. 

Though adsorption need not be followed by absorption, absorption depends upon the concentration of the molecules at the surface or interface. Acidic and basic dyes which can be distinguished by their staining power are important tools not only in histological studies, but also In experimental physiology, where they serve to trace the pathway and distribution of dissolved substzinces across cells and tissues. The rate of their entrance into cells depends to some extent on their accumulation on cell surfaces prior to penetration. The cell colloids contain... 

Crystal violet is an excellent stain that is widely used in cytology, histology, and bacteriology. It is a typical basic dye that can be dissolved in both water and alcohol, allowing the staining of cell nuclei. Crystal violet staining is often used in the evaluation of cytotoxicity and growth inhibition assays. 

Adsorption. Adsorption (qv) is an effective means of lowering the concentration of dissolved organics in effluent. Activated carbon is the most widely used and effective adsorbent for dyes (4) and, it has been extensively studied in the waste treatment of the different classes of dyes, ie, acid, direct, basic, reactive, disperse, etc (5—22). Commercial activated carbon can be prepared from lignite and bituminous coal, wood, pulp mill residue, coconut shell, and blood and have a surface area ranging from 500—1400 m /g (23). The feasibiUty of adsorption on carbon for the removal of dissolved organic pollutants has been demonstrated by adsorption isotherms (24) (see Carbon, activated carbon). Several pilot-plant and commercial-scale systems using activated carbon adsorption columns have been developed (25—27). 

Basic Explosives Manufacture. The major quantities and the toughest problems are here. They include a) acid waters, treated with lime or soda ash, chemical washes, spills, washdowns b) Red Water from TNT purification. A complex, brick-red soln of Na nitrate, Na sulfate, Na sulfite, Na nitrite, and about 17% organics which include sulfonated nitrotoluene isomers and complex, unidentified dye-bodies c) dissolved expls, eg, Pink Water which is approx lOOppm TNT in w d) suspended expl particles — dust and chips and e) sometimes solvents such as acet, benz, and dimethyl aniline... 

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