Thiosulphate, sodium, cyanide

Bromides and iodides interfere because of the liberated halogen the test is not trustworthy in the presence of chromates, sulphites, thiosulphates, iodates, cyanides, thiocyanates, hexacyanoferrate(II) and (III) ions. All of these anions may be removed by adding excess of nitrate-free Ag2S04 to an aqueous solution (or sodium carbonate extract), shaking vigorously for 3-4 minutes, and filtering the insoluble silver salts, etc. 

Silver chloride is readily soluble in ammonia, the bromide less readily and the iodide only slightly, forming the complex cation [Ag(NH3)2]. These halides also dissolve in potassium cyanide, forming the linear complex anion [AglCN) ] and in sodium thiosulphate forming another complex anion, [Ag(S203)2] ... 

Methaemoglobin forming compounds should be used cautiously in victims suffering from concurrent carbon monoxide poisoning or hypoxia. The second approach calls for provision of additional sulfur groups to enhance the detoxification of cyanide and thiocyanate by endogenous rhodanese this comes about by giving sodium thiosulphate. 

HCN is detoxified to thiocyanate (SCN ) by the mitochondrial enzyme rhodanese rhodanese catalyzes the transfer of sulfur from thiosulfate to cyanide to yield thiocyanate, which is relatively nontoxic (Smith 1996). The rate of detoxification of HCN in humans is about 1 pg/kg/min (Schulz 1984) or 4.2 mg/h, which, the author states, is considerably slower than in small rodents. This information resulted from reports of the therapeutic use of sodium nitroprusside to control hypertension. Rhodanese is present in the liver and skeletal muscle of mammalian species as well as in the nasal epithelium. The mitochondria of the nasal and olfactory mucosa of the rat contain nearly seven times as much rhodanese as the liver (Dahl 1989). The enzyme rhodanese is present to a large excess in the human body relative to its substrates (Schulz 1984). This enzyme demonstrates zero-order kinetics, and the limiting factor in the detoxification of HCN is thiosulphate. However, other sulfur-containing substrates, such as cystine and cysteine, can also serve as sulfur donors. Other enzymes, such as 3-mercapto-pyruvate sulfur transferase, can convert... 

Schulz, V., R.Gross, T.Pasch, J.Busse, and G.Loeschcke. 1982. Cyanide toxicity of sodium nitroprusside in therapeutic use with and without sodium thiosulphate. Klin. Wochensch. 60 1393-1400. 

The electrical conductivities of soln. of a great many compounds in liquid hydrogen halides have been measured by E. H. Archibald and D. McIntosh. The conductivity is raised considerably by phosphoryl chloride. Sodium sodium sulphide, borate, phosphate, nitrate, thiosulphate, and arsenate chromic anhydride potassium nitrate, hydroxide, chromate, sulphide, bisulphate, and ferro- and ferri- cyanide ammonium fluoride and carbonate j rubidium and caesium chloride magnesium sulphate calcium fluoride ... 

A further method of extraction of the selenium from the mud is based on the solubility of the element in solutions of potassium cyanide, forming selenocyanide. The solution deposits selenium when acidified, and any sulphur is retained in solution as thiocyanic acid.2 Treatment with a solution of an alkali hydroxide, or fusion with sodium carbonate (the latter more especially for the extraction of selenium from the dust of the flues between the pyrites burners and the Glover tower), has also been applied, the mass being extracted with water in the latter case. The resulting aqueous solutions deposit selenium on atmospheric oxidation, whilst any extracted sulphur passes mainly to thiosulphate.3... 

Based on the avidity of cobalt for cyanide ions, intravenous injection of the cobalt EDT A complex has been recommended as being the best antidote in cyanide poisoning73). Earlier therapy was based on sodium nitrite and sodium thiosulphate, with partial conversion of haemoglobin to methaemoglobin. 

Jones [5] carried out a simultaneous separation of non organic cations (eg calcium, potassium and sodium) also anions (eg nitrate, thiosulphate, cyanide and thiocyanate) by ion chromatography using a single column coated with weak/strong charged three welterionic bile salt micelles. 

The precipitate is insoluble in ammonium sulphide, ammonium polysulphide, ammonia, potassium cyanide, or sodium thiosulphate. Silver sulphide can be precipitated from solutions containing diammine-, dicyanato- or dithiosulphato-argentate complexes with hydrogen sulphide. 

The precipitate is insoluble in dilute or concentrated ammonia, but dissolves readily in potassium cyanide (POISON) (a) and in sodium thiosulphate(b) ... 

Silver cyanide is soluble in ammonia solution and in sodium thiosulphate solution, but is insoluble in dilute nitric acid. 

The precipitate is insoluble in ammonia [distinction from hexacyanoferrate(III)] and nitric acid, but soluble in potassium cyanide and sodium thiosulphate ... 

Silver nitrate solution white, curdy precipitate of silver chloride, AgCl, insoluble in water and in dilute nitric acid, but soluble in dilute ammonia solution and in potassium cyanide and sodium thiosulphate solutions (see under Silver, Section III.6, reaction 1, also under Complex Ions, Section 1.33) ... 

Silver nitrate solution curdy, pale-yellow precipitate of silver bromide, AgBr, sparingly soluble in dilute, but readily soluble in concentrated ammonia solution. The precipitate is also soluble in potassium cyanide and sodium thiosulphate solutions, but insoluble in dilute nitric acid. 

At 18° C. the solubility of the bromide is 0-109 mg. per litre of water.7 Besides ammonium hydroxide, it dissolves in sodium-thiosulphate solution, forming the double salt 2NaaS203,AgaS203,2H20,8 and in solutions of bromides and potassium cyanide. Its heat of formation from its elements is given as 22-7 Cal.,9 and 20-7 to 28-7 Cal. according to the condition of the bromide produced.10... 

Aurous cyanide forms yellow, microscopic laminae, very slightly soluble in Water. It is more stable than aurous iodide, but at red heat is decomposed into gold and cyanogen. Its insolubility renders it immune to the action of dilute acids and hydrogen sulphide, but solutions of ammonia, potassium hydroxide, ammonium sulphide, and sodium thiosulphate dissolve it, probably forming complex derivatives. In aurous cyanide the tendency to form complex compounds is much more marked than in the corresponding chloride, bromide, and iodide.3 Its interaction with potassium ferrocyanide has been studied by Beutel.4... 

Cannon, E.P., Leung, P., Hawkins, A., Petrikovics, I., DeLoach, J., Way, J.L. (1994). Antagonism of cyanide intoxication with murine carrier erythroc des containing bovine rhodanese and sodium thiosulphate. J. Toxicol. Environ. Health 41 267-74. 

Hall, A.H., Dart, R., Bogdan, G. (2007). Sodium thiosulphate or hydroxocobalamin for the empiric treatment of cyanide poisoning Ann. Emerg. Med. 49 806-13. 

On boiling bromobenzyl cyanide with an aqueous-alcoholic solution of sodium thiosulphate, the sodium salt of cyanobenzyl thiosulphuric acid is formed ... 

---