Is Potassium ferricyanide poison? Is Prussian Red antidote of Radioactive Thallium? What is the difference between potassium ferrocyanide and ferricyanide?

K₃[Fe(CN)₆]

Potassium ferricyanide is a chemical compound. This bright red salt is soluble in water and its solution shows some green-yellow fluorescence. It was discovered in 1822 by Leopold Gmelin.

Application of Potassium ferricyanide

The compound is also used to harden iron and steel, in electroplating, dyeing wool, as a laboratory reagent, and as a mild oxidizing agent in organic chemistry.

Blueprinting and photography

The compound has widespread use in blueprint drawing and in photography (Cyanotype process). Several photographic print toning processes involve the use of potassium ferricyanide.

Sensors and indicators

Potassium ferricyanide is also one of two compounds present in ferroxyl indicator solution (along with phenolphthalein) that turns blue (Prussian blue) in the presence of Fe2+ ions, and which can therefore be used to detect metal oxidation that will lead to rust.

In histology,

potassium ferricyanide is used to detect ferrous iron in biological tissue. Potassium ferricyanide reacts with ferrous iron in acidic solution to produce the insoluble blue pigment, commonly referred to as Turnbull's blue or Prussian blue.

Medical use

Prussian blue, also known as potassium ferric hexacyanoferrate, is used as a medication to treat thallium poisoning or radioactive caesium poisoning. For thallium, it may be used in addition to gastric lavage, activated charcoal, forced diuresis, and hemodialysis. It is given by mouth or nasogastric tube

Formula: K₃[Fe(CN)₆]Molecular Weight: 329.24 g/mol
Form: deep red crystals, sometimes small pellets, orange to dark red powder
CAS Number: 13746-66-2
Density: 1.89 g/cm³
Synonyms: Prussian Red, Potassium hexacyanoferrate(III), Red prussiate, rotes Blutlaugensalz, Kaliumhexazyanoferrat(III)