Hydroxynaphthol Blue

Hydroxynaphthol Blue tri-Na salt [63451-35-4] M 620.5, m dec on heating, pKE,t <0. Crude material was treated with hot EtOH to remove soluble impurities, then dissolved in 20% aqueous MeOH and chromatographed on a cellulose powder column with propanol EtOH water (5 5 4) as eluent. The upper of three zones was eluted to give the pure dye which was ppted as the monosodium salt trihydrate by adding cone HCl to the concentrated eluate [Ito and Ueno zfna/ysr 95 583 1970. ... 

Fraga etal. [71] have proposed a new stripping voltammetric method for the determination of titanium and Co(II) [72] based on the adsorptive accumulation of its hydroxynaphthol blue complex on a static mercury drop electrode. 

The dyes Rhodamine 6G [55] and Crystal Violet [56] form extractable ion-associates with the anionic complexes of nickel with chloro-oxine [551 and 4-chloro-2-nitroso-l-naphthol [56], (e = 7.7-10 - 8.2-10 ). The ion associate of Rose Bengal with the cationic nickel complex with 1,10-phenanthroline, extractable into nitrobenzene, is also the basis of a sensitive method (e > 1-10 ) [57]. Hydroxynaphthol Blue has been applied for determination of Ni in the presence of Cu by the derivative spectrophotometry method [58]. 

If it is desired to titrate only this can be done at pH 12 (use NaOH), where Mg(OH)2 is precipitated and does not titrate. Hydroxynaphthol blue indicator is used. 

T. Yamane, Flow Injection Determination of Hydrogen Peroxide by Means of the Manganese-Catalyzed Oxidation of Hydroxynaphthol Blue. Bunseki Kagaku, 33 (1984) E203. 

K. Uchida, M. Tomoda, and S. Saito, Determination of Calcium by Flow Injection Analysis with Hydroxynaphthol Blue [in Japanese]. Bunseki Kagaku, 34 (1985) 568. 

Hydroxynaphthol blue, trisodium salt C2oH 4N2Na30 S3 63451-35-4 620.471 dk red cry ... 

Strictly, the name Hydroxynaphthol blue applies to the trisodium salt. p 4 4 pA s 12.93. 

Hydroxynaphthol blue, H-00371 3-[[4-(Diethylamino)phenyl]azoj-1,4-dimethyl-1//-1,2,4-triazolium(l -I-) Chloride, in D-00328... 

Hydroxy-2-naphthoic acid, H-00369 Hydroxynaphthol blue Tri-Na salt, in... 

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