Hydrogen cyanide

Hydrogen cyanide

Hydrogen cyanide, whose term in the official nomenclature is: hydrogen cyanide is an acid also known as: prussic acid, hydrocyanic acid or form nitrile.
Hydrocyanic acid has a brute or molecular formula: HCN and is a weak acid with a brute formula whose salts are called cyanides.
From the physical point of view at room temperature it is a colorless volatile liquid, whose vapors have a typical smell of bitter almonds.
It is a very reactive and extremely toxic compound: 300 ppm of hydrogen cyanide vapors in the air can kill a person in a matter of minutes.
The toxicity of this molecule is linked to the cyanide ion (CN-) which, combining with the copper and iron present in the active site of the cytochrome c oxidase enzyme, blocks the electron transport chain and, consequently, cellular respiration.
The fatal oral dose is approximately 1-2 milligrams per kilogram of body weight, while a higher dose leads to near-instant death.
Hydrocyanic acid is industrially produced and used as an intermediate reagent in the synthesis of numerous chemical compounds, such as plastics, dyes, explosives, drugs.

It is produced by reaction between a cyanide and a strong acid, or by direct synthesis starting from ammonia and methane at 1 200 ° C with a platinum catalyst.
Hydrocyanic acid can originate from the hydrolysis of amygdalin, a genetic cyan glycoside contained in the bitter varieties of the almond tree (Prunus dulcis (Mill.) D.A.Webb, 1967).
The bitter taste of these almonds is largely linked to the presence of amygdalin (2-4%), which by hydrolysis gives rise to hydrogen cyanide. Hydrolysis occurs thanks to the presence of an enzyme, called emulsin, present within the bitter almonds themselves, which decomposes amygdalin into benzaldehyde, glucose and hydrogen cyanide. The same process occurs in the intestine, thanks to the B-glycosidase enzymes produced by the intestinal flora, which therefore make bitter almonds a potential and dangerous poison for humans.
Thus, the ingestion of a small number of bitter almonds can be fatal: it is estimated that 6-10 seeds are sufficient to cause fatal poisoning in the child, while for an adult the lethal dose is around 50-60 units. Fortunately, the markedly bitter taste of these almonds, which is proportional to their amygdalin content, strongly discourages their intake. Symptoms of hydrogen cyanide poisoning include headache, vomiting, confusion, increased frequency and depth of breaths, loss of consciousness, seizures.

Warning: The information shown is not medical advice and may not be accurate. The contents are for illustrative purposes only and do not replace medical advice.