Potassium rhodizonate

Bromophenol blue 2, 7 -DichIorofluorescein Eosin, tetrabromofluorescein Fluorescein Potassium rhodizonate, C404(0K)2 Rhodamine 6G Sodium 3-aIizarinsuIfonate Thorin Dissolve 0.1 g of the acid in 200 mL 95% ethanol. Dissolve 0.1 g of the acid in 100 mL 70% ethanol. Use 1 mL for 100 mL of initial solution. See Dichlorofluorescein. Dissolve 0.4 g of the acid in 200 mL 70% ethanol. Use 10 drops. Prepare fresh as required by dissolving 15 mg in 5 mL of water. Use 10 drops for each titration. Dissolve 0.1 g in 200 mL 70% ethanol. Prepare a 0.2% aqueous solution. Use 5 drops per 120 mL endpoint volume. Prepare a 0.025% aqueous solution. Use 5 drops. 

Procedure 24. Determination of Plutonium in Urine by Co-cryataXlization with Potassium Rhodizonate W. H. Shipman and H. V. Weiss (Ref. 374)... 

Pu is co-orystallized with potassium rhodizonate by adding an equal volume of ethyl alcohol to a pH 9 solution of the reagent in urine. The Pu is further purified by co-precipitation with LaFg and adsorption on an anion exchange resin. 

Potassium rhodizonate (Paul B. Elder Co., Bryan, Ohio). 

Add 1 g of potassium rhodizonate to the sample. (If the urine is not fresh, solubilization of the reagent may be difficult. Under such circumstances acidification of the sample with HCl to pH 2 to 3 effects rapid solution.) Adjust to pH 9 with 5 N NaOH and crystallize the rhodizonate with 500 ml of absolute ethyl alcohol. Let stand for several minutes and isolate the crystals by centrifugation. 

Sodium rhodizonate Strontium (II), Sr2 Ammonium carbonate Dilute sulfuric acid Saturated calcium sulfate Potassium chromate Ammonium oxalate... 

Group IV. Ca, Sr, and Ba This is a difficult separation. The metals are present as chlorides. The solvent used is pyridine containing 20 per cent (v/v) water and 1 per cent (w/v) potassium thiocyanate. The elution is allowed to proceed for 5-6 hours in an atmosphere saturated with respect to pyridine and also with a relative humidity of between 65 and 80 per cent the latter is attained by the use of a saturated aqueous solution of ammonium nitrate or chloride. The solvent front moves about 20 cm. The strip is dried, and then sprayed with a saturated alcoholic solution of alizarin to identify Ca, and with 0 5 per cent (w/v) aqueous sodium rhodizonate (freshly prepared) to reveal Ba and Sr. The RF values are Ca, 0-95 Sr, 0-75 Ba, 0-15 (see Fig. VI.5c). 

In Inorganic Chemistry, typical spray reagents for cations include potassium iodine (0.2%, aqueous), hydrogen sulphide (saturated aqueous solution), ammonium sulphide (0.2 N, aqueous), quercetin (0.1%, alcoholic), l-(2-pyridylazo)-2-naphthol (PAN) (0.2%, methanolic), oxine (8-hydroxyquinoline) (1% methanolic, view under visible and UV light), and sodium rhodizonate (0.5%, aqueous). Reaction with dithizone to produce coloured dithizonate chelates of many metals is particularly suitable if quantitative spectrometric analysis (in situ or after elution) is to be carried out. Anions are detected with bromocresol purple (0.1%, alcoholic), 1% ammoniacal silver nitrate + 0.1% alcoholic fluorescein/UV light, zirconium alizarin lake (0.1% in HC1 solution), and ammonium molybdate (1%, aqueous) followed by SnCl2 (1%) and HC1 (10%). Typical detection limits range from 10 ng (10 9g) to several pg (10 6g). 

Sodium rhodizonate soln, filter paper impregnated with saturated soln of potassium chromate... 

The cochineal-coloured solid was examined by J. F. Heller, who showed that it is the potassium salt of what he called rhodizonic acid (poSi ojy I colour rose-red), and he also examined croconic acid. His results were mostly confirmed by A. Werner. Liebig found that rhodizonate of potash dissolved in water forms the croconate and oxalate, and hence he suggested the formula 504 + 0203 = 0707 for rhodizonic anhydride. For rhodizonate of potash he... 

The constitution of the above substances was first elucidated by R. Nietzki and Th. Benckiser. They converted nitranilic acid ( -dinitrodihydroxyquinone), C (N02)2(0H)202, into hexahydroxybenzene, C3(OH)e(I), which was identical with Lerch s trihydrocarboxylic acid, hence the black potassium carboxide (COK)n is not CjoKioOio but Ce(OK)e, derived from hexahydroxybenzene (I). Rhodizonic acid they found was dihydroxydiquinoyl (II), C6(0H)204, identical with Lerch s carboxylic acid. Leuconic acid is C5(OH)io, formulated as III. 

The detection of cations on chromatoplates is performed by spraying the solutions of the detection reagents at an appropriate concentration level, followed by visualization of the separated zones. The spraying reagents used as detectors include, 0.04-1 % dithizone in chloroform or carbon tetrachloride, 1% ethanolic solution of dimethylglyoxime, 1% aqueous solution of potassium ferrocyanide, 1% aqueous aluminon containing sufficient amount of ammonium acetate, 1% alcoholic solution of alizarine Red S, freshly prepared 0.1% solution of stannous chloride in 2 M HCl, hydrogen sulfide gas, aqueous saturated solution of ammonium sulfide, aqueous solution of ammonium thiocyanate and dilute solutions of diphenylcarbazide, p-nitroso-yV,A -dimethylaniline and sodium rhodizonate. 

Procedure. A drop of the test solution is placed on filter paper impregnated with a saturated solution of potassium chromate the chromates are formed. After a minute, a drop of an aqueous 0.2 % solution of sodium rhodizonate is placed on the spot. A brown-red fleck or circle indicates the presence of strontium. Limit of Identification y stiori i xm I in the presence of 80 times the... 

The electronic spectra of the potassium salts of squarate 2, croconate 3, and rhodizonate (4) ions in aqueous solution exhibit bands with high molar absorptivity, in the order of 10 1 mol cm , and a similar profile for all the spectra, with unfolded bands (Figure 5.2). 

Feigl et al. (1972) describe several spot tests for lead, including using sodium rhodizonate, dithizone, and potassium iodide. Sulfide solutions have been used to detect lead in paint (Vind and Matthews, 1976 Sayre, 1970). Proprietary kits for detecting lead in paint based on sodium sulfide or rhodizonate are being marketed, and other kits are available for detecting lead in other species (Luk et al., 1990). Results from spot test kits are discussed in the paragraphs that follow. 

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