Amygdalin, cyanide poisoning from

Poisoning with cyanide may occur in a variety of ways accidental or intentional poisoning with cyanide salts, which are used in industry or in laboratories as a result of exposure to hydrogen cyanide in fires when polyurethane foam burns from sodium nitroprusside, which is used therapeutically as a muscle relaxant and produces cyanide as an intermediate product and from the natural product amygdalin, which is found in apricot stones, for example. 

Hydrocyanic acid is most easily prepared from its potassium salt, K(CN), which is obtained principally by the decomposition of the complex double cyanides of iron as we shall soon consider. The acid is also obtained by the hydrolysis of certain glucosides, e.g., amygdalin, in bitter almonds. It is prepared synthetically by reactions to be discussed presently in connection with the constitution of it and its salts. It is a colorless liquid with a characteristic odor and burns with a violet flame. It boils at 26.1 and solidifies to crystals which melt at —14°. It is an extremely strong poison the best antidotes being chlorine and hydrogen dioxide. It is readily absorbed by metallic nickel which is thus used in gas masks for this purpose. It is stable in dry air but in presence of water is readily hydrolyzed yielding ammonia and formic acid as the chief products. 

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