Chromal Blue

Uesugi K, Nagahiro T. 1983. A highly sensitive spectrophotometric determination of uranium with chromal blue G in the presence of cetytrimethylammonium chloride. Analytica Chimica Acta 148 315-320. 

Triphenylmethane chelating reagents, other than CAS and ECR, have also been used to determine beryllium, e.g. Aluminon [34,35], Xylenol Orange [36], Brilliant Violet B [2], and Chromal Blue G (e = 3.1-10 ) [37]. A considerable increase of sensitivity is obtained by using Chromal Blue G in the presence of CTA (e = 9.4-10 at 626 nm) [38]. 

Other triphenylmethane reagents, besides the Eriochrome Cyanine R and Chrome Azurol S discussed above, have been applied for determination of Fe(III). A large increase in sensitivity and significant bathochromic shifts are observed when the reactions are performed in the presence of cationic surfactants, CTA, CP, Zephiramine, or dimethyllaurylbenzylammonium ions [70]. Systems of Fe(III) with Pyrocatechol Violet and CTA [71], Chromal Blue G and CTA [72], and Sulphochrome and CP [73] have been applied. The molar absorptivities of these systems are within 1.3-10 -1.7-10. The methods based on Pyrogallol Red alone or with the use of surfactants are less sensitive (e within 5.2-10 -7.5-10 ) [74-76]. 

A considerable increase in the sensitivity of methods for palladium determination has been found with triphenylmethane reagents in ternary systems that include cationic surfactants, e.g., Eriochrome Cyanine R with CP [79], Chromal Blue G with CTA (e = 1.0-10 ) [80], Chrome Azurol S-CTA (or -CP) [81], Eriochrome Azurol B-CTA (e = 1.15-10 ) [82], and Eriochrome Azurol G-CTA [83]. 

The following triphenylmethane dyes have been employed for determination of Sc similarly to Xylenol Orange Methylthymol Blue [33], Chrome Azurol S [34,35], Chromal Blue G [36], and Eriochrome Brilliant Violet B [37]. Much higher sensitivities have been obtained in the presence of some cationic surfactants [38 0]. In the method with Chrome Azurol S and Zephiramine, the e value is 1.5-10 at 610 nm, and in the method with Eriochrome Cyanine R and CP, e = 9.2-10" at 600 nm [40]. When o-hydroxy-quinonephthalein and CP are used, the molar absorptivity is 1.1-10 at 555 nm [41], Scandium has been determined with the use of Nile Blue in a poly(vinyl alcohol) medium [42]. 

Triphenylmethane reagents have gained considerable importance in the determination of uranium [110]. In this group it is worth mentioning Chrome Azurol S, especially if used in the presence of cationic surfactants (CP, CTA, Septonex, etc.) (pH 4-5, e = 1.010 -1.2-10 at -630 nm) [111-115]. Other reagents suggested include Eriochrome Cyanine R (with CP) [116], Eriochrome Azurol B (pH 4-7 with CTA or CP, e = 1.3510 ) [114], and Chromal Blue G (with CTA) [117]. 

Chloro-4 -nitro-4 -hydroxy-3,3 -dimethylfuchsone-5,5 -dicarboxylic acid (Chromal Blue G) (C22H 503NC1)... 

Strictly, the name Chromal blue G applies to the disodium salt. 

Chromal blue G Di-Na salt, in C-00275 Chromazurol S Tri-Na salt, in C-00277 Chrome black special Mono-Na salt, in C-00278... 

Bromochlorophenol blue, B-00497 Bromocresol green, B-00498 Bromocresol purple, B-00499 Bromophenol blue, B-00542 Bromophenol red, B-00543 Bromophthalexon S, B-00559 Bromopyrogallol red, B-00574 Bromothymol blue, B-00581 Bromoxylenol blue, B-00583 Butylrhodamine B, in R-00002 C.I. Basic blue 20 Dichloride, in C-00002 C.L Basic violet 2 B, HCl, in C-00003 >Ceplac, in E-00020 2 -Chlorofluorescein, C-00116 4 -Chlorofluorescein, C-00117 Chlorophenol red, C-00197 Chromal blue G Di-Na salt, in C-00275 Chromazurol S Tri-Na salt, in C-00277 Chrome green G, C-00283 Chromoxane violet R, in E-00015 Chromoxan violet 5B, C-00295 o-Cresolbenzein, C-00305 m-Cresolphthalein, C-00306... 

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