AMMONIA

From Big Medical Encyclopedia

AMMONIA (NH 3 ) — chemical compound of nitrogen with hydrogen, colorless gas with the characteristic pungent odor irritating mucous membranes. Meets in small amounts in air, river and sea water, the soil, especially in those places where there is a decomposition of organic nitrogen-containing matters (see. Rotting ).

Ammonia was received for the first time by the English scientist D. Priestley (1774) at effect of hydrated lime on ammonium muriate. In 1787 for Ammonia the name «ammoniak» was offered, a cut remained behind it in various countries. In Russia in 1801 the chemist Ya. D. Zakharov replaced this name with shorter «ammonia».

In vitro Ammonia receive replacement it from ammoniac salts solutions of strong alkalis during the heating:

2NH 4 Cl + Ca(OH) 2 → 2NH 3 + CaCl 2 + 2H 2 O.

In the Ammonia equipment receive synthetic by the method developed by the German chemist F. Haber. Synthesis of Ammonia is carried out as follows: mix of nitrogen with hydrogen compresses by means of the compressor to 200 — 220 atm and under such pressure is passed via the contact device containing the catalyst (iron with additive of aluminas and potassium). After passing over the catalyst the gases containing about 10% And., come to a cooler, and then in a number of the devices Ammonia it is absorbed by water.

In the presence of the cheap electric power necessary for creation of high temperature, And. synthesize by the cyanamide method based on interaction of atmospheric nitrogen and calcium carbide. At high temperature both substances react with each other with formation of nitrolime which at effect of superheated water vapor and pressure of 6 atm easily breaks up with A.

Plotnost's education of Ammonia at t ° 0 ° and pressure of 760 mm of mercury. (1 atm) it is equal to 0,589. Weight of 1 l — 0,771 g. With a pressure of 7 atm and room temperature Ammonia is in liquid state. With a pressure of 1 atm during the cooling to t ° — 40 ° it is liquefied. During the cooling to t ° — 75 ° crystallizes. And. it is well adsorbed by active coal. Let's well dissolve in water. In one water volume at the room temperature 750 volumes of A. V saturated aqueous solution are dissolved 33% contain A. Rastvor of Ammonia in water is called «spirit of ammonia». With water A. forms very fragile connection — hydrate of an oxide of ammonium (NH 4 OH), the representing mild base.

From aqueous solution of Ammonia it is easily allocated, especially during the heating; burns in oxygen with formation of water and nitrogen:

4NH 3 + 3O 2 → 2N 2 + 6H 2 O;

in the presence of catalysts is oxidized to nitric oxide.

Solution of Ammonia in water has alkalescent reaction since it contains hydroxylic ions (IT - ). The last arise thanks to the fact that nek-paradise a part of molecules A. connects to hydrogen ions of water: NH 3 + HOH = NH +4 + OH - . A part of hydroxylic ions contacts ions of ammonium, forming hydrate of an oxide of NH ammonium +4 + OH - = NH 4 OH. From this it follows that solution A. contains at the same time molecules of ammonia, ions of NH +4 and IT - . However the main weight dissolved And. is in a type of molecules.

Liquid And. at evaporation absorbs a large amount of heat (327 kcal on 1 g) thanks to what it was applied in refrigerating business. Value A is especially big. as source of receiving nitric to - you and its salts. Synthesis of Ammonia with use of atmospheric nitrogen, quantity to-rogo almost inexhaustible, allows to resupply nitrogenous substances in the soil and to do it to more fertile. For use as fertilizers from And. in large numbers prepare ammonium sulfate and ammonium nitrate.

In pharmaceutical practice apply spirit of ammonia of various fortress. Ofitsinalny solution shall contain 10% of Ammonia This solution receive commodity 25% of solution A by watering.

Ammonia takes the central place in a nitrogen metabolism of plants. Through root system ammoniac salts come to plants in very insignificant quantities since contents them in the soil is small. Ammonia in the soil is exposed to oxidation as a result of life activity of nitrifying bacteriums, and the salts of nitrogenous and nitric acids which are formed at the same time are used after preliminary education from them And. for synthesis of amino acids (and from them proteins) and other nitrogen-containing substances (see. Nitrogen metabolism ).

Ammonia is formed also in a human body and animals. A source of its education are the amino acids which are a part of animal fabrics, and also adenylic to - that. However contents And. in fabrics, blood and cerebrospinal liquid it is very insignificant (0,01 — 0,1 mg of %). It is explained by the fact that in body tissues formed And. is eliminated by synthesis amides (see). Elimination of Ammonia (in an organism of animals the glutamine is synthesized preferential) is the all-biological process happening in microorganisms, plants and an organism of animals. End product of neutralization and elimination And. in a human body is urea (see).

Ammonia is formed at reduction of muscles, excitement of nervous tissue. The Ammonia which is formed at muscle work partially is eliminated, partially comes to blood. And. comes also to blood from intestines. It from a human body and animals with urine in the form of ammoniac salts is allocated (hl. obr. ammonium sulfate). At acidosises release of Ammonia with urine sharply increases. Main source And. urine is glutampn, blood where he is deamidized under the influence of a glutaminase brought to kidneys.

Quantitative definition of Ammonia is made on a neutralization test of acid: 2NH 3 + H 2 SO 4 → (NH 4 ) 2SO 4 . Unused acid is titrated alkali liquor in the presence of the indicator — methyl orange. Ammonia is quantitatively determined also by staining reaction with Nessler's reagent (caustic solution of a merkuriyodid of potassium K 2 Hg 2 I 4 ). For definition of Ammonia in air a certain volume it is stretched by means of an aspirator through absorption flasks from 10 N solution a chamois to - you, and then defined titirimetric or colorimetric.

Use of ammonia in medicine

Irritant action And. and its salts it is used in medical practice. The reflexes arising at irritation of mucous membranes of upper respiratory tracts promote excitement of a respiratory center, especially at its oppression (a suffocation, poisoning etc.). Inhalation of Ammonia causes increase of breath and increase in arterial pressure; at action of big concentration, on the contrary, there is an apnoea and delay of pulse. Besides, at long action of high concentration And. on site its uses can arise inflammatory and necrobiotic changes in fabrics. And. possesses also disinfecting action.

From drugs A. the greatest therapeutic use has spirit of ammonia (Solutio Ammonii caustici, Liquor Ammonii caustici, Ammonium causticum solutum, NH 4 OH) — 10% aqueous solution of Ammonia the Transparent colorless liquid with a pungent smell of A. Smeshivayetsya with water and alcohol in any ratios. Spirit of ammonia causes irritation of receptors of mucous membranes and reflex excites respiratory and a vessel odvigatelny the centers. Its use at unconscious states or an alcoholic poisoning is connected with this property (inhalation or intake on 5 — 10 drops in 100 ml of water). Action on a respiratory center is short, and long stimulation of breath requires use of analeptics. In surgical practice spirit of ammonia is applied as a desinfectant to washing of hands (25 ml on 5 l of warm water — Kochergin's way — Spasokukotsky).

At chronic arthritises and neuralgia as a revulsive apply ammoniac linimentum (Linimentum ammoniatum, linimentum flying, Linimentum volatile) — homogeneous ropish liquid of yellow-white color with A. Poluchayut's smell agitation of mix of sunflower-seed oil (74 parts) and olein to - you (1 part) with solution A. (25 parts).

Solution A. at intake renders expectorant effect (see. Nashatyrno-anisovye of a drop ).

Solutions of Ammonia apply to neutralization of acid toxins at stings of insects, snakes and a karakurta (lotions or injections to the place of a sting). There are data on use of weak solutions A. (0,1 — 0,2%) as anti-inflammatory drug at felons, furuncles, abscesses, etc.

Professional harm

Poisonings And. in conditions of production acute are more often and arise only at emergency cases; hron. poisonings are possible, but meet less often.

A threshold of a reflex effect for the person — 25 mg/m 3 . The feeling of irritation is observed at 100 mg/m 3 . Work is complicated at 140 — 210 mg/m 3 , it is impossible — at 350 mg/m 3 above.

At acute poisonings cold, irritation and a pharyngalgia, hypersalivation, an osiplost of a voice, a hyperemia of mucous membranes of upper respiratory tracts and eyes develops.

At a serious poisoning the feeling of constraint and a stethalgia, severe pristupoobrazny cough, suffocation, a headache, a stomach ache, vomiting, an ischuria joins. There comes sharp disorder of breath and blood circulation. The burn of a mucous membrane of upper respiratory tracts and development of the phenomena of pneumonia is possible, the toxic fluid lungs is more rare. There is a strong excitement. In some cases the inflammation of bronchial tubes and lungs is a cause of death. At direct hit on skin or a mucous membrane of eyes the chemical burn is possible. Opacification of a cornea and loss of sight, hoarseness of a voice, sometimes its total loss, hron can be effects of the postponed acute poisoning. bronchitis, activation of tubercular process.

Hron. poisonings can develop at continuous influence of low concentration of Ammonia Concentration And. 40 mg/m 3 is a threshold hron. actions (round-the-clock influence). In urine of the poisoned animals contents considerably increases And. During the opening at the animals who underwent poisoning the purulent inflammation of a trachea and bronchial tubes, pneumonia and pleurisy is observed; pathological changes from parenchymatous bodies, apparently, are connected with reaction to a burn.

Ammonia in an organism is quickly neutralized and therefore its cumulative action is insignificant or it is even a little probable. At hron. poisoning at people loss of sense of smell, conjunctivitis, hron is observed. Qatar of mucous membranes of a nose, upper respiratory tracts and bronchial tubes.

First aid: at hit in eyes of splashes of ammonia solutions it is necessary to wash out immediately eyes running water. Then apply liquid or luccu oil, novocaine with adrenaline, a sulfacetamide - sodium (albucid - sodium). At hit on skin of splashes immediately to wash away a strong water jet. At damage of skin gaseous And. — lotions of 5% of solution acetic or lemon to - you. At poisoning — fresh air, inhalation of the acidified warm steam, 10% menthol in chloroform, soft drugs (codeine, dionine — 0,01 g), oxygen, warmly.

At a laryngospasm — local heat, inhalation, atropine, according to indications tracheotomy. Cardiacs according to indications. At an apnoea — an artificial respiration. Treatment of N prevention fluid lungs (see).

Prevention comes down to sealing of the equipment and communications. During the work on dangerous sites it is necessary to apply the filtering industrial gas mask of brand K (a green box) and to systematically control concentration of Ammonia in air of production rooms.

Maximum allowable concentration in the atmosphere of production rooms — 20 mg/m 3 .

Ammonia in the medicolegal relation

Ammonia can cause poisoning in gaseous state or at intakes in the form of aqueous solutions. A clinical picture at poisoning of A. (per os) is similar to that, edges is observed at poisoning with pyretics, however there are features: characteristic smell of emetic masses, cold, dacryagogue, severe cough; paresis of the lower extremities is observed. At court. - a medical research pay attention to the bright red color of a mucous membrane of a mouth, throat, gullet and stomach sometimes accepting more dark coloring. In lungs focal pneumonia, in kidneys — the phenomena of acute nephrite is observed.

At necropsy the smell of Ammonia remaining within several days is felt. For court. - chemical high-quality detection And. ability of its vapors to paint the red litmus paper and a piece of paper moistened with copper sulfate solution in blue color is used. For an exception of the Ammonia which is formed during the rotting biol. objects, testing with the piece of paper impregnated with solution of lead acetate is in parallel carried out. At the same time there is a blackening in the presence of hydrogen sulfide, the accompanying Ammonia during the rotting. At a posineniya of the two first pieces of paper and darkening of the third establishment of availability of the Ammonia which came to an organism by a chemical method is already impossible.

Quantitative definition of Ammonia at a research of cadaveric material cannot be, as a rule, made.


Bibliography

Zakusov of V. V. Pharmakologiya, page 186, M., 1966; Goats N. B. Ammiak, his exchange and a role in pathology, M., 1971; Mashkovsky M. D. Pharmaceuticals, p.1, page 393, M., 1972; Remy G. Kurs of inorganic chemistry, the lane with it., t. 1, page 587, M., 1972; Goodman L. S. a. Gilman A. Pharmacological basis of therapeutics, N. Y., 1970.

Professional harm

Alpatov I. M. Studying of toxicity of gaseous ammonia, Gigabyte. work and the prof. having got sick., No. 2, page 14, 1964; Alpatov I. M. and Mikhaylov V. I. Research of toxicity of gaseous ammonia, in the same place, No. 12, page 51, 1963; Volfovskaya R. N. and Davydova G. N. Clinical observations over acute poisonings with ammonia, Saturday. nauch. works Leningr. in-that gigabyte. work, page 155, 1945; Harmful substances in the industry, under the editorship of N. V. Lazarev, the p. 2, page 120, L., 1971, bibliogr.; Mikhaylov V. I., etc. Influence of small concentration of ammonia on some biochemical and physiological indicators at the person, the Gigabyte. work and the prof. having got sick., No. 10, page 53, 1969, bibliogr.

D. L. Ferdman; V. K. Lepakhin (pharm.), E. N. Marchenko (prof.), M. D. Shvaykov (court.).

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