Disodium nitroprusside

Phenol reagent (flow-analysis) 35 g of phenol and 0.4g of disodium nitroprusside dihydrate [Na2Fe(CN)5N0-2H20] with 100 mL of ethanol are diluted and made up to IL with pure water. This stock solution is stable for about 4 weeks if kept at < 8 °C. The working solution is prepared by diluting 350 mL of the stock to 1 L with pure water and is stable for about one week if kept at < 8 °C. 

RiminPs test (for primary aliphatic amines). To a suspension or solution of 1 drop of the compound or to an equivalent quantity of its solution in 3 ml of water, add 1 ml of pure acetone and 1 drop of a freshly prepared 1 per cent aqueous solution of disodium pentacyanonitrosoferrate(m) (nitroprusside). A violet-red colour will develop within 1 minute. 

The Acetest tablets contain a mixture of glycme, sodium nitroprusside, disodium phosphate, and lactose. Acetoacetate or acetone (to a lesser extent) in the presence of glycine forms a lavender-purple complex with nitroprusside. p-hydroxybutyrate does not react with nitroprusside. The disodium phosphate provides an optimum pH for the reaction, and lactose enhances the color. 

A color reaction based on the inoiganic reagent disodium pentacyano nitrosylferrate Na2[FE(CN)5(NO)], commonly called sodium nitroprusside, is used in the test. This reagent has been widely used for two different reactions that have formed the basis of photometric determinations of a large variety of compoxmds. 

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