Cobalt nitrate reagent

Other Methods of Preparation.—Ethyl 2-(D-ara6i no-tetrahydroxybutyl)-5-methyl-4-furoate has been prepared by heating D-glucose plus ethyl acetoacetate in aqueous alcohol without a catalyst,1 or from the same reagents (1 g. and 0.5 ml., respectively) in 0.5 ml. of 96% ethanol plus 1.5 ml. of water at room temperature in the presence of ferric chloride, zinc chloride (with small quantities of hydrochloric acid or of sodium hydroxide), cupric chloride, ferric sulfate, zinc sulfate, aluminum chloride, nickel chloride, or cobalt nitrate.18... 

Place a drop of the test solution (which should be slightly acid, preferably with dilute sulphuric acid), a drop of 0-5m cobalt nitrate solution, and a drop of the ammonium tetrathiocyanatomercurate(II) reagent on a spot plate or in a micro crucible. A blue precipitate is formed. 

Cobalt nitrate solution adding a few drops of the reagent to a solution of the hypochlorite, a black precipitate of cobalt(III) hydroxide is obtained ... 

Reagent. A 1 % solution of cobalt nitrate in ethanol. Method. Dissolve the sample in 1 ml of ethanol, add 1 drop of the reagent followed by 10 il of pyrrolidine, and agitate the mixture. 

Molybdenum trioxide (MoO ), cobalt nitrate (Co(NO )2.6H20), nickel nitrate (Ni(N0j>2.6H20, thioacetamide (CH3CSNH2), urea NH2CONH2), (all from LOBA Chemie), nitric acid (BDH), cyclohexene (Fluka), thiophene (Kodak) were all of analytical reagent grade. (Harshaw, S.A. 234 m g, P.V., 0.65 ml g ). 

Modras (51) reported spot test reactions to differentiate hydralazine from closely related drugs. Reagents used were aqueous copper (I) chloride, aqueous ammonium molybdate, iodine in potassium iodide solution, aqueous cobalt (II) nitrate, alcoholic ninhydrin, and alcoholic bromophenol blue. The tests were performed on paper or on Silica Gel G. 

OXIDATION, REAGENTS Dimethylsulf-oxide-Acetic anhydride. 1-Amyl hydroperoxide. N-Bromosuccinimide. Ceric ammonium nitrate. Chloramine. o-Chlo-ranil. 1-Chlorobenzotriazole. N-Chloro-succinimide-Dimethyl Sulfide. Chromic acid. Chromic anhydride. Chromyl chloride. Cobalt(ll) acetate. Cupric acetate monohydrate. Cupric nitrate-Pyridhic complex. 2,3-Dichloro-5,6-dicyano-l, 4-benzoquinonc. Dicyclohcxyl-18-crown-... 

Detection of barbituric acids is possible non-specifically by chromatography on so-called fluorescent layers, e. g., silica gel GF254. If not present in too small amounts, they appear in short wave UV light as spots of quenched fluorescence. A popular method of detection has been with mercury compounds, especially mercurous nitrate (Rgt. No. 157) which yields insoluble barbiturates [10, 34, 43, 56, 77, 140, 166]. The sensitivity of response varies with the barbituric acid. A combined spray reagent of a mercuric salt and diphenylcarbazone solutions (No. 156) has been often used the spots then stand out better against the background [32, 93, 160]. Cobalt salts have been used with various bases for detection (Zwikker-reaction and modifications, Rgt. No. 51) [56, 152, 170, 174]. N-methylated barbituric acids do not react since the second nitrogen atom cannot take part in enolisation [98]. A further, non-specific method... 

Cobalt(Il) nitrate-ammonia (Zwikker reagent) for barbiturates. 

Spray reagent 1 2% cobalt (II) nitrate solution in anhydrous... 

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