Ammonium nitroprusside

Ammonium nitroprusside, (NH4)2[Fe(CN)5NO]9 obtained by decomposing the barium salt with ammonium sulphate, crystallises m reddish plates, which are readily soluble in water.6... 

Nitroprusside (sodium) A solution made by mixing sodium nitroprusside (1.5 g), 2 N hydrochloric acid (5 ml), methanol (95 ml), and 25% ammonium hydroxide (10 ml) is sprayed on the plate to... 

The samples for on-line analysis were taken through a polysulfone membrane [37]. The seven channel automatic analyzer system consisted of six air-segmented continuous flow-wet chemical analyzers (Skalar analytics) to measure the concentration of ammonia with ion selective electrode (Philips IS-570), phosphate with ammonium molybdate at 880 nm, reducing sugar with pHBAH at 410 nm, methionine with Na-nitroprusside at 505 nm, cephalosporin C with... 

Sulphate, (i) BaCl2 solution and dilute HC1 test, and reduction to sulphide test for latter with sodium nitroprusside or lead acetate solution (IV.24, 1). (ii) Lead acetate test and solubility of PbS04 in ammonium acetate solution (IV.24, 2). 

Properties.—An aqueous solution of sodium nitroprusside deposits Prussian blue on exposure to light. In the presence of alkali sulphides— as, for example, ammonium sulphide—it yields a beautiful purple colour, which is very characteristic, and so sensitive that the presence of 0 0000018 gram of hydrogen sulphide in 0 004 c.c. can easily be detected.2 Ammonium hydroxide does not hinder the colour formation, but caustic alkalies destroy it. It gradually fades on standing, in consequence of oxidation of the sulphide to sulphite. The composition of the purple substance is uncertain, but Hofmann 3 suggests the formula Na3[Fe(CN)5(0 N.SNa)], since, by the action of thio-urea, CS(NH2)2, upon sodium nitroprusside, he obtained the complex derivative Na3[Fe(CN)5(0 N.SCNH.NH2)], as a carmine-red powder, closely similar to the substance under discussion.4... 

When aqueous sodium nitroprusside solution is treated with sodium hydroxide, the quaternary nitrito sodium salt, Na4[Fe(CN)5NO2]10H2O, is obtained.4 It crystallises in yellowish red monosymmetric tablets, and is very soluble in water, yielding a dark red coloration with ammonium sulphide. 

Sodium ammonio ferrocyanide, Na3Fe(CN)5.NH3, is obtained when ammonium hydroxide is allowed to act at 0° C. on a solution of sodium nitroprusside in methyl alcohol.5... 

Chloride is determined by mercurimetric titration to the sodium nitroprusside end-point. Carbonates, acetates and borates do not interfere in the titration but large amounts of ammonium salts do interfere. The method has been applied to methyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, phenylmethyldichlorosilane and phenyltrichlorosilane. Methods have been described76,77 based on reaction with amines for the determination of chlorine directly linked to silicon in alkyl aryl chlorosilanes. One method76 is based on the formation of aniline hydrochloride according to the equation ... 

Add 4 g of ammonium sulphate R and the test solution is mixed. Dropwise and without mixing 0.2 ml of a 100 g/1 solution of sodium nitroprusside R in dilute sulphuric acid R is added. Still without mixing, 1 ml of concentrated ammonia R is added. After at the most 30 min, a dark green ring appears at... 

The salicylate-nitroprusside method determines the ammonia nitrogen (NH3-N) by reacting ammonia with a salicylate-nitroprusside solution to produce color intensity proportional to the concentration. Automation can be used to analyze multiple samples rapidly for ammonium products and urease conversion digestions. Often, Methods 5 and 9 in combination are analyzed spectrophotometrically for ammonia nitrogen and phosphate using an autoanalyzer. 

Ammonium ion is one of the inorganic species most frequently determined by UV-visible spectrophotometry. It is freed by the Kjeldahl method from organic matter and can be spectrophotometrically determined by reaction with phenol and hypochlorite in the presence of nitroprusside ion, with which it yields a blue compound (indophenol) with an absorbance maximum at 625 nm. Another alternative, especially avoiding the use of phenol, is by measuring the absorbance at 660 nm of an indophenol blue derivative generated by the reaction of ammonium ion with sodium salicylate in the presence of hypochlorite ion. These procedures are routinely used for the determination of ammonium ion with autoanalyzers. 

Ammonium is determined in many laboratories in a CF system in which the Berthelot reaction is implemented. In the Berthelot reaction, ammonium reacts with chlorine and phenol in the presence of sodium nitroprusside as catalyst in alkaline medium. EDTA is added to prevent interference of calcium and magnesium. Modern systems have been developed that use macroporous polytetrafluoroethylene (PTFE) membranes. In these systems a sample is introduced into a stream to which sodium hydroxide solution is added. Ammonia diffuses through the PTFE membrane into a stream of de-ionized water and the stream is fed through the flow-through cell of a conductivity meter. In this system a minimum of reagents is required and the only interference is from volatile amines. 

The hemlock alkaloids also can be separated on silica gel G layers [137], using chloroform-absolute ethanol-25 % ammonium hydroxide (90 + 10 + 10). The ammonia is expelled by heating 5 min at 110° C before visualisation with iodine vapour in a desiccator the amines give brown spots. After spraying with l-chloro-2,4-dinitrobenzene solution (Rgt. No. 44) or with bromothymol blue solution (Rgt. No. 31), the bases appear as blue spots on a yellow background. y-Coniceine turns red when sprayed with sodium nitroprusside solution (Rgt. No. 186). 

Our assay for the detection of active acetate was based on the enzymic reaction with sulfanilamide. In the presence of the enzyme obtained from pigeon liver, the acetylation of sulfanilamide increased with increasing addition of active acetate . In our purification work we used, however, another, much less time-consuming assay which was based on the delayed color development as given by thiolesters with sodium nitro-prusside. When ammonium hydroxide is added to the mixture of thiolesters and nitroprusside no color is seen in the first moment. It only gradually develops in the following minutes due to the hydrolysis of the thiolester in the alkaline medium. The... 

In analytical biochemistry, urinary ketonic derivatives may be detected by using Legal s reaction according to Rothero s experiment. Pathological dimethylketone is first salted out from urine by ammonium sulfate. A violet color develops with nitroprusside in ammonia. 

Procedure To 5 ml of dilute aqueous ethanol solution four drops of hydrogen peroxide (12%) and 0.5 ml of 4% ferrous ammonium sulfate are added and allowed to stand for 10 min. A few drops of piperidine are then added and the solution is filtered to get rid of the precipitated iron oxides. Three drops of the 3% sodium nitroprusside solution are added to the filtrate to give a blue color (39). 

Citric Acid. After oxidation with permanganate, citric acid gives color reactions with sodium nitroprusside (123) or resorcinol (124). However, the detection based on its conversion to citrazinic acid, whose ammonium salt shows a strong blue fluorescence, is much more important (125). 

Urea gives a yellow color with / -dimethylaminobenzaldehyde (6), a positive biuret reaction (p. 271), a color reaction with sodium nitroprusside in alkaline media in the presence of ammonium persulfate (red color) (7), a color reaction with phenol and sodium hypochlorite (8), a very sensitive reaction with phenylhydrazine and aniline (9), and a reaction with xanthydrol (10). 

Sulphate, chloride (Cl ), nitrate (NO ), and ammonium (NH ) in water were measured with a Technicon Autoanalyzer II system by the methylthymol blue, mercuric thiocyanate, cadmium reduction and sodium nitroprusside methods, respectively. Sulphate and Cl in highly colored samples were measured by means of ion chromatography. Cations were analyzed with an atomic-absorption spectrophotometer by means of flame-emission spectrophotometry for potassium (K ) and... 

Sources.—Glutathione was isolated in 1921 from yeast, muscle, and mammalian liver by Hopkins, and identified as the compound responsible for Morner s cysteine reaction—the development of a violet colour when the tissue is treated with sodium nitroprusside (nitroferricyanide) and ammonium hydroxide. The reaction is specific for the ihiol or svlphydryl group, —SH, and is given by most... 

Sodium Nitroprusside Test for Acetoacetic Acid and Acetone (Rothera).—Fill up about 1 in. of a test tube with solid ammonium sulphate. Add 5 ml. of urine, and shake so as to saturate the mixture. Add 2-4 drops of fresh 5 per cent, sodium nitroprusside, and make alkaline with about 10 drops of strong ammonium hydroxide. A deep violet colour develops in a few seconds if the urine contains more than 0-2 per cent, acetoacetic acid, while 0 005 per cent, will give a pink colour in about ten minutes. 

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