R-salt

In the production of sodium 3-hydroxy-2,7-naphthaIenedisulfonate/7Jj5 -j5 -J7 (R-salt) (38), 2-naphthol is stirred with excess 98 wt % sulfuric acid at 60°C, sodium sulfate is added, and the mixture is stirred and heated for 36 h at 105—122°C (77). The charge is diluted with water and salted out with ca 15 wt % sodium chloride at 60°C to give R-salt in 68% yield. 

For colorimetric or gravimetric determination l-nitroso-2-naphthol can be used. For chromatographic ion exchange (qv), cobalt is isolated as the nitroso-(R)-salt complex. The cyanate complex is used for photometric determination and the thiocyanate for colorimetry. A rapid chemical analysis of... 

Co (II) with nitroso-R-salt on the bases of gelatin film ... 

Estriol Dip the concentrating zone of a precoated H PTLC silica gel 60 plate in a saturated ethanolic solution of Fast Dark Blue R salt, allow the solvent to evaporate, apply the sample solution and dip once [10, 59]... 

The analytical capability of these matrices has been demonstrated for chiral amines [12, 13]. The procedure is illustrated in Fig. 8-4 for the separation of NapEtNH " CIO . Concentrated methanol/dichloromethane solutions of the racemic mixture were placed on a column containing the chiral macrocycle host. The enantiomers of the ammonium salts were resolved chromatographically with mixtures of methanol and dichloromethane as the mobile phase. The amounts of R and S salts in each fraction were determined by polarimetry. Because the chiral supported macrocycle interacts more strongly with S salts, the R salt passes through the column first and the S salt last, as seen in Fig. 8-4. 

Discussion. An excellent method for the colorimetric determination of minute amounts of cobalt is based upon the soluble red complex salt formed when cobalt ions react with an aqueous solution of nitroso-R-salt (sodium 1-nitroso-2-hydroxynaphthalene-3,6-disulphonate). Three moles of the reagent combine with 1 mole of cobalt. 

Procedure. The test solution should contain between 0.001 and 0.02 mg of cobalt. Evaporate almost to dryness, add 1 mL of concentrated nitric acid, and continue the evaporation just to dryness to oxidise any iron(II) which may be present. Dissolve the residue in 10 mL of water containing 0.5 mL each of 1 1 hydrochloric acid and 1 10 nitric acid. Boil for a few minutes to dissolve any solid material. Add 2.0 mL of a 0.2 per cent aqueous solution of nitroso-R-salt and also 2.0 g of hydrated sodium acetate. The pH of the solution should be close to 5.5 check with bromocresol green indicator or with a pH meter. Boil for 1 minute, add 1.0 mL of concentrated hydrochloric acid, and boil again for... 

Cupferron Nitroso-R-salt 688 Nitrous acid removal of. 514 Nonaqueous titrations 307 indicators for, 284 solvents for. 283... 

V. Tonsvik, R. Salte, R. Sorheim, and J. Goksoyr, Comparison of phenotypic diversity and DNA heterogeneity in a population of soil bacteria, Applied and Environmental Microbiology 56 116 (1990). 

General FAQs, Morton(r) Salt, Morton International http //www.mortonsalt.com/faqs/fprflfaqs.htm... 

Verify that the aqueous solution of the diazo salt does not couple with the sodium salt of /S-naphthol nor with a solution of R-salt.1... 

The presence of HMX as an impurity in RDX is not a problem when the product is used as an explosive. However, the need for an analytical sample of RDX makes other more indirect methods feasible. One such method involves the oxidation of 1,3,5-trinitroso-1,3,5-triazacyclohexane (109) ( R-salt ) with a mixture of hydrogen peroxide in nitric acid at subambient temperature and yields analytical pure RDX (74%) free from HMX." The same conversion has been reported in 32 % yield with three equivalents of a 25 % solution of dinitrogen pentoxide in absolute nitric acid. l,3,5-Trinitroso-l,3,5-triazacyclohexane (109) is conveniently prepared from the reaction of hexamine with nitrous acid at high acidity. ... 

Samples of metal complexes isolated from the final solutions were subjected to microanalysis (for carbon, hydrogen, oxygen, and sulfur). Metals were determined colorimetrically by the following methods— copper as the complex formed with sodium diethyl dithiocarbamate (6) cobalt as the nitroso-R salt complex (7) nickel as the dimethylglyoxime complex (4). 

The completeness of coupling may be checked by the R-salt test as follows A few drops of the clear supernatant liquid is added to a small quantity of a solution of R-acid (jS-naphthol-3,6-disulfonic acid) in an excess of 2 TV sodium hydroxide. An intense red color is produced if unreacted diazonium salts are present. Obviously this test is satisfactory only if R-acid couples more rapidly with the diazonium salt than the coupling agent involved in the reactions and if the change to a red color is not obscured by other colors present in the reaction system.]... 

Nitroso-R-salt see l-nitroso-2-naphthol-3,6-disulphonic acid, disodium salt, hydrate. 

Dawson, P. R. and Tillerson, J. R., Salt Motion Following Nuclear Waste Disposal, Proceedings of the International Conference on Evaluation and Prediction of Subsidence, to be published, 1978... 

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