30 silver solution. Silver nitrate

Name:

Silver nitrate (Argentnitras)

Pharmachologic effect:

In small concentrations of silver, nitrate has an astringent and anti-inflammatory effect, and in stronger solutions it cauterizes tissue. It has bactericidal (bacteria-destroying) properties.

Indications for use:

Used externally for erosions (superficial defect of the mucous membrane), ulcers, excessive granulations (formation of connective tissue at the site of the wound surface), cracks, acute conjunctivitis (inflammation of the outer membrane of the eye), trachoma (an infectious eye disease that can lead to blindness), for chronic hyperplastic laryngitis (chronic inflammation of the larynx, accompanied by the formation of inflammatory folds and ridges in it), etc. Prescribed in the form of aqueous solutions, ointments, and also in the form of lapis pencils.

Method of application:

Externally, a 2-10% solution and 1-2% ointment are used to lubricate the skin and for cauterization, and a 0.25-2% solution is used to lubricate the mucous membranes.

Previously, it was sometimes prescribed for chronic gastritis and gastric ulcers as an anti-inflammatory drug orally in the form of a 0.05% solution of 10-20 ml (0.005-0.01 g) for adults 15 minutes before meals. A solution (2%) of silver nitrate was previously widely used to prevent blenorrhea (acute purulent inflammation of the outer membrane of the eyes) in newborns. To do this, immediately after birth, the child wipes the eyelids with cotton wool (a separate swab for each eye), slightly retracts the lower eyelid, lifts the upper eyelid and releases one drop of 2% silver nitrate solution from a sterile pipette onto the conjunctiva (outer shell of the eye). After this, the eyelids are carefully released. After instillation, the eyes are not washed. The silver nitrate solution must be fresh (one day old) and not contain sediment. Currently, a 30% sulfacyl solution or other antibacterial drugs are used for this purpose. Higher doses for adults orally: single - 0.03 g, daily - 0.1 g.

Adverse events:

Not found.

Contraindications:

Not installed.

Release form of the drug:

0.05% and 2% solutions and in the form of a lapis pencil.

Storage conditions:

List A. In well-closed jars with a ground stopper in a dark place. Lapis pencils - in polyethylene pencil cases in a cool, dark place.

Synonyms:

Lapis, Nitrate silver.

Compound:

A hard white or grayish-white stick of a conical shape with a rounded top. Contains 0.18 g of silver nitrate.

Drugs with similar effects:

Kerasal Vokadine (solution) Wokadine Wokadine (ointment) Wokadine (vaginal pessaries) Anti-angin

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Rp.: Sol. Argenti nitratis 2% 30 ml

D.S. For lubrication

Having prepared a tempering bottle made of dark glass with a ground-in stopper, a stand and a funnel with a small and relatively dense cotton filter, the latter is washed with almost boiling freshly distilled water to remove soluble organic substances. The first rinsing waters are used to rinse the stand, and the subsequent ones are used for bottles and stoppers. Under no circumstances should wash water be returned to the filter.

After this preparation, 30 ml of freshly distilled water is measured into the stand, filtered into a release bottle, ensuring that there are no insoluble particles visible to the naked eye. 0.6 g of silver nitrate is dissolved in the filtrate in the dispensing bottle and the solution is visually checked for the absence of insoluble contaminants, which are sometimes introduced along with an insufficiently pure preparation. If there are specks in the solution, it has to be filtered, considering this operation as an extreme necessity.

If there is a glass filter (No. 2), then the solution can be prepared in the usual way, that is, in a stand with subsequent filtering of the liquid.

Solutions of silver nitrate must be sealed when dispensing. Dispensing solutions with a concentration above 2% (up to 10%) is carried out exclusively in the hands of a doctor or by his power of attorney, certified by his own seal. The dispensing of silver nitrate solutions to maternity hospitals for the prevention of neonatal blenorrhea is permitted in a concentration of no more than 2% with the designation on the label “For newborns” and indicating the percentage of the solution concentration in numbers and words.

Content

The active substance silver nitrate is used in medicine due to its antiseptic properties. The Latin name is Argentum nitricum or Lapis infernalis, the second is translated as “hellish lapis”. Silver nitrate was so named because of its strong causticity. The therapeutic effect is exerted by diluted solutions used in dentistry, ophthalmology, and other areas of medicine, along with other antibacterial drugs.

What is silver nitrate

The combination of silver salt with nitric acid forms the formation of colorless, tasteless and odorless diamond-shaped crystals, the so-called lapis pencils. The substance dissolves in water, alcohol, and darkens in direct sunlight. Hellstone has been known in medicine since ancient times as an antiseptic. Nitrate has an astringent effect; wounds, ulcers, and warts are cauterized with solutions. The effect in organic chemistry is based on the fact that silver ions disrupt the metabolism of pathogenic microbes.

Properties

The use of a drug based on metal nitrate is justified by its anti-inflammatory effect. Metal salts bind the sulfhydryl and carboxyl groups of amino acids, causing protein denaturation. Due to this property, it is used in the manufacture of medicines, applied externally or internally, depending on the concentration. You cannot use pure nitrate: it is an extremely caustic substance that can cause a chemical burn.

Formula

The structural formula of the pure substance is AgNO3. For medical purposes, water and alcohol solutions and ointments are used in medications. Methods of use depend on the purpose. Silver nitrate solution varies from 0.05% to 10%. The dosage is determined by a doctor; it is necessary to consult before use. Sometimes the drug is prescribed orally: metal ions have an astringent effect, stopping diarrhea of ​​microbial origin.

Silver nitrate in medicine

As a rule, solutions and ointments based on lapis are used externally. Due to the property of destroying protein compounds and stopping the metabolism of pathogenic bacteria, the substance remains one of the most effective antiseptics and has a pronounced anti-inflammatory effect. The use of a weak solution is permissible on mucous membranes and skin. Beneficial effects of lapis:

• for ulcers and erosions, it has an epithelializing effect;
• helps heal cracks;
• in acute conjunctivitis, relieves inflammation;
• in case of burns, frostbite, removes necrotic tissue;
• cauterizes warts and benign tumors;
• stops diarrhea, has an astringent effect.

For internal use, tablets based on white clay are prescribed, which helps neutralize the excess causticity of the substance. Medicines based on the substance are used for gastritis, stomach and duodenal ulcers; the effectiveness of lapis against the bacteria Helicobacter pylori, which is the main cause of inflammatory diseases of the gastrointestinal tract, has been proven.

Instructions for use of silver nitrate

When used externally, lapis has an epithelizing, anti-inflammatory effect, and has bactericidal properties. The solution for this application should be weak, from 0.1% to 0.5%. In this form, the substance treats fissures, conjunctivitis, throat diseases - laryngitis, pharyngitis, purulent skin lesions. Ointment with silver nitrate can be prescribed to cauterize warts and remove tumors, then the concentration of the substance reaches 30%.

Indications for use

Methods of using the drug are determined by the purpose and localization of the disease. The main indications for which the substance is widely used are dental diseases - stomatitis, ulcers on the mucous membranes. Compositions that have cauterizing properties are used in cosmetology. Oral preparations based on the substance are prescribed for stomach ulcers, duodenal ulcers, and erosive gastritis. The wide range of uses of lapis implies many indications, in each case patients should consult a doctor.

Side effects

Hellstone is not a harmless remedy. Silver lapis in concentrated form can cause severe burns, so it is not recommended to make solutions yourself. A common side effect of long-term, especially internal, use is argyria, a special condition caused by the body's reaction to excess metal. It is characterized by a change in skin color: the epidermis becomes a characteristic bluish tint, the hair loses its natural pigment. To avoid argyria, strictly follow the dosage prescribed by your doctor.

Contraindications

Preparations based on silver lapis are well tolerated by the human body. In rare cases, allergic reactions may occur, although intolerance to metal ions or other components is very rare. If unwanted side effects occur, you must immediately stop using the solution, tablets or ointments; in case of external use, rinse the skin or mucous membrane with clean water. The description of the drug includes the concentration, specificity, properties of a particular drug, do not violate the terms of use.

Silver nitrate price

Medicines based on silver nitrate are available in a wide range of pharmacies. They are sold in the form of a concentrate or ready-to-use medicines. The cost depends on the brand, dosage, area of ​​use. Remember that the properties of drugs depend on the composition and concentration, therefore, although the drugs are sold without a prescription, be sure to consult with your doctor regarding the choice of a specific drug.

Silver nitrate(silver nitrate, lapis) – colorless transparent crystals in the form of plates or white cylindrical rods, odorless, darken when exposed to light.

Silver nitrate is stored in well-closed jars with a ground stopper, in a place protected from light.

Silver nitrate reacts with chloride compounds that are part of sweat. Usually 1 - 10% solutions are used (in various solvents), which interact with salts of sodium chloride and calcium chloride of the fatty substance. As a result of the reaction, silver chloride is formed; under the influence of sunlight or ultraviolet rays, it easily disintegrates and turns into metallic silver, which colors the handprint in a dark brown (even black) color.

Handprints are detected using silver nitrate on porous (sweat-absorbing) surfaces.

Age of formation of traces, which are detected by solutions of silver nitrate, as a rule, does not exceed 6 months.

It is not recommended to detect handprints with silver nitrate solutions on dark and variegated surfaces, since the identified trace (dark brown or black) will be practically invisible against a dark or variegated background, which precludes further examination.

The use of silver nitrate precludes further medical and biological study of the trace substance.

Method for identifying hand marks using silver nitrate solutions:

PREPARATION OF SOLUTIONS

Silver nitrate solutions prepared in the laboratory

Solution No. 1

Solution No. 2

Solution No. 3

The sequence of mixing ingredients in solutions No. 1-3 must correspond to the order in which they are listed.

The amount of silver nitrate can be changed by 1-1.5 g, both in the direction of decreasing and increasing its amount.

Solution No. 4. Aqueous solution of iodine with silver nitrate solution

An aqueous solution of iodine is prepared according to the following scheme:

First, an aqueous solution of iodine is prepared - powdered iodine is dissolved in cold water at the rate of 0.5 g of iodide powder per 30 g of cold distilled water. The process of dissolving iodine continues for up to three hours, after which the solution is filtered.

The filtered iodine solution is mixed with the same amount of 3% silver nitrate solution, resulting in the formation of silver iodide.

Add 2-3 drops of acetone to the mixture.

The prepared solution is stored in a dark container.

Ready solutions of silver nitrate

Ready-made solutions of silver nitrate in various solvents produced by a number of foreign companies have the following advantages:

No time spent on preparation;

Convenient packaging, if necessary, can be used at the scene of an incident;

The presence of a spray bottle, which facilitates the process of applying the solution to the object;

Long shelf life.

PROCESSING OBJECTS

Solutions of silver nitrate are applied to the surface to be treated in the following ways:

Spraying (using a spray bottle);

With a cotton swab or soft brush (tangential or blotting movements).

After treatment, the surface is dried and then irradiated with light containing a high content of ultraviolet rays. The object can be exposed to sunlight or illuminated with a mercury-quartz lamp not shielded by a light filter; the irradiation time depends on the power of the ultraviolet illuminator and is determined experimentally (until a clearly visible trace appears, colored brown or black). The duration of the development process depends on the composition of the sweat-fat substance of the trace, its age, the chemical composition of the trace-receiving surface, the irradiation power and can last from several minutes to several hours.

The entire development process must be constantly monitored. The appearance of traces stops when color appears on the trace-receiving surface.

Identified traces are immediately photographed and stored in an envelope made of light-proof paper.

If traces are detected on thick paper from which banknotes, bonds, etc. are made, it is advisable to use a solution with a higher concentration of silver nitrate in distilled water.

An aqueous solution of iodine with silver nitrate (see solution No. 4) is applied to the surface using a spray bottle or a cotton swab. It is necessary to ensure that the solution covers the surface to be treated in an even layer. If excess solution forms on the surface, it is removed with filter paper. Further actions are similar to those described above.

The use of other means of identifying traces in combination with treatment with silver nitrate solutions

The use of iodine vapor may precede the staining of hand marks with silver nitrate.

It is acceptable to use solutions of silver nitrate to detect handprints after treating the object with a solution of ninhydrin.

Discoloration of identified traces

If there is a need to return the object to its original appearance (lapis leads to a change in the color of the entire document), this can be done with one of the following mixtures:

1. A solution of mercuric chloride (4%) and a saturated solution of table salt.

2. Sodium sulfate (5%) and red blood salt solution. First, a solution of mercuric chloride is applied to the mark with a brush or cotton swab, and then solutions of the indicated salts. The mark immediately becomes discolored. After this, the paper is washed with water and dried.

3. 3% solution of sodium cyanide or potassium cyanide. Solutions are applied to the mark using a brush. The mark immediately becomes discolored. The paper is washed with water and dried.

In most cases, it is not possible to return an object to its original appearance 100%.

ALLOXAN SOLUTIONS

Alloxan(mesoxalyl urea, C 4 H 2 O 4 N 2) is a white crystalline substance. Soluble in water and alcohol, turns pink in air. Aqueous solutions are colorless, have an acidic reaction, and when they come into contact with the skin, they turn it pink.

The use of alloxan to detect hand marks is based on its ability to react with protein breakdown products (when processing a trace, alloxan reacts with the breakdown products of protein compounds that make up sweat) and color them from orange to red. In ultraviolet rays, handprints revealed by alloxan tend to luminesce.

Alloxan solutions are used to detect colorless hand marks on porous surfaces. Alloxan is sensitive to nitrogen-containing substances, so it is not recommended to use it to detect traces on coated high-quality papers that contain substances of the amine nitrogen group.

The use of an alloxan solution to detect handprints precludes further biological research.

Method for detecting handprints using alloxan solutions:

PREPARATION OF SOLUTIONS

1-2% solutions of alloxan in acetone

The solution is prepared in laboratory conditions, under hood. 98-99 g of solvent is poured into a glass chemical container and about 1 - 2 g (depending on the desired solution concentration) of alloxan are added. The contents are mixed with a glass rod until the crystalline precipitate is completely dissolved.

To treat traces older than 10 days, it is permissible to use solutions with a higher concentration of alloxan, up to 3 g.

Alloxan solution in freon

The solution is used to avoid dyes from bleeding on a document if its contents are important for other types of research or there is a possibility that the diffuse dye will fill most of the background of the document, spoiling the identified handprints.

To detect handprints, prepare a saturated solution of alloxan in ethyl alcohol, then dilute it with freon in a ratio of 1:4 by volume.

PROCESSING OBJECTS

A solution of alloxan is evenly applied to the surface to be treated using a cotton swab or spray bottle. After this, the object must be exposed to daylight for 2 - 3 hours, and then it is placed in a light-proof container. The mark begins to color after 2 hours. The complete chemical process is completed after 24-28 hours. The tracks turn orange.

The slow reaction of alloxan with traces complicates its prompt use and lengthens the time required for examinations. This drawback is eliminated by the express method of developing traces.

A reagent with alloxan is applied to the surface to be examined (a sheet of paper) using a cotton swab. After the acetone has evaporated, the surface is generously moistened with a 1% solution of copper nitrate in acetone. Then it is immediately (before the solution dries) subjected to intensive heat treatment. To do this, cover the object with a sheet of paper and run a hot iron over it, or place the object under study over an electric stove. Traces appear immediately.

The proposed technique reduces the development time from several hours or even days to several minutes, but in this case the background of the object may become colored, thereby reducing the contrast of the detected traces.

The detected traces in UV rays give a bright crimson luminescence, which makes it possible to use alloxan for treating traces on multi-colored surfaces.

Discoloration of the background and marks of hands treated with alloxan.

When processing marks on paper that does not have sizing (newspaper, wrapping paper, etc.), a colored background may appear, which can be weakened with a 1.5% solution of copper nitrate in acetone, acidified with 2 drops of 10% nitric acid.

If a document with traces of alloxan needs to be restored to its original appearance, it is recommended to moisten it with 15% hydrogen peroxide.

Use of other handprint detection tools in combination with alloxan treatment

The use of alloxan does not exclude the possibility of treating the trace with ninhydrin and subsequently turning it purple. If the traces under study have a weak color, they are additionally treated with ninhydrin, which affects other components of the sweat-fat substance.

SOLUTION OF IODINE IN AN AQUEOUS SOLUTION OF POTASSIUM IODIDE

Crystalline iodine– grayish-black plates or clumps of crystals with a metallic sheen with a characteristic odor. Volatile at ordinary temperatures, when heated it sublimes, forming violet vapors. Slightly soluble in water, easily soluble in an aqueous solution of iodides, soluble in 10 parts of 95% alcohol, ether, chloroform. Store in glass jars with ground stoppers, in a cool place, protected from light.

Potassium iodide– colorless or white cubic crystals or white fine-crystalline powder, odorless, salty-bitter taste. It gets damp in humid air. Let's dissolve in 0.75 parts of water, 12 parts of alcohol and 2.5 parts of glycerin. Stored in well-sealed orange glass jars.

Iodine tends to react with zinc and copper, forming water-soluble zinc iodide (ZnI2) and slightly water-soluble white copper iodide (CuI).

Copper iodide has the property of good adhesion to metal and is able to contrastly reveal traces of sweat and grease on objects made of copper and alloys based on it (brass, tombac).

Handprints are detected in a neutral environment at room temperature. Unprotected areas of the metal are painted white, and areas protected by the sweat-fat substance of the trace darken under the influence of iodine or remain unchanged. The hand mark is revealed positively.

The method allows us to identify not only fresh tracks, but also traces formation age 30-60 days.

Method for identifying hand prints using a solution of iodine in an aqueous solution of potassium iodide :

PREPARATION OF SOLUTION

The solution is prepared according to the following scheme:

1 g of potassium iodide is dissolved in 10 ml of distilled water at room temperature;

Add 0.1 - 0.2 g of crystalline iodine,

Stir until the components are completely dissolved

The finished solution should be transparent, yellow-brown in color.

The solution is prepared immediately before processing objects.

PROCESSING OBJECTS

Place the object in the container with the prepared solution so that it does not touch the walls (for example, fix it with tweezers). Every 5 – 10 sec. the object is removed and inspected in good lighting using a magnifying glass. As soon as the papillary lines have appeared in sufficient contrast, the treatment is stopped, the object is washed with distilled water and dried in a stream of warm air. Once identified, the trace is photographed.

Many may be surprised, but the chemical compound silver nitrate (Argenti nitratis in Latin) was not so rarely mentioned in Russian literature. The hero of Turgenev’s novel “Fathers and Sons,” Bazarov, died because he did not have lapis on hand in time.

Lapis (in Latin Lapis means “Stone”) can still be found in the form of sticks, ointments or solutions. The lapis pencil or stick has long been used as a disinfectant and bactericidal agent. Bazarov (the hero of the novel) cut himself while opening the corpse of a man who died of typhus. If Evgeniy had immediately treated the wound with lapis, the novel would have had a different ending. But Bazarov got to lapis only after 3 hours and received blood poisoning, which they could not treat at that time.

There are many other (possibly more effective) disinfectants available today, but silver nitrate still finds use in medicine. It has many names: lapis, silver nitrate, hellish (devil's) stone. It is used in the treatment of damage (erosions) of the mucous membranes, ulcers, skin cracks, conjunctivitis and other diseases.

In small concentrations, lapis has an anti-inflammatory and astringent effect, and at higher concentrations it cauterizes. Therefore, when writing a prescription, the doctor will definitely indicate the concentration and regimen of use of the medicine.

Lapis is used externally in the form of 2-10% solutions, 1-2% ointments or lapis pencils. To lubricate the mucous membranes, a 0.2-2% solution is recommended. Previously, this drug was prescribed to adults for oral administration in the treatment of stomach ulcers and chronic gastritis. In this case, it was prescribed to use a 0.05% solution 15 minutes before meals. Today, in such cases, other antibacterial drugs are prescribed.

Of the side effects of lapis, the only possible allergy can be noted in people susceptible to it. However, it is recommended to consult a doctor before using lapis.

The solution should be stored in jars with a ground-in stopper in a dark place for no more than one day; there should be no sediment in it. Lapis pencils (small sticks with a rounded end, white or grayish) are stored in plastic pencil cases (in a cool, dark place). It is curious that a light lapis pencil leaves black marks on the skin.

If you hold a lapis pencil in your hands for a long time, you can get burned. It is possible to use this medicine in homeopathy in the treatment of certain gastric diseases.

Chemical properties

The chemical formula of lapis is AgNO3. Not to be confused with AgNO2: this is silver nitrite, which has nothing to do with medicine.

Silver nitrate is obtained by combining the metal with nitric acid according to the formula: Ag + 2HNO_3 = AgNO_3 + NO_2 + H_2O.

This nitric acid salt is used to detect hydrochloric acid. When hydrochloric acid or its salts react with silver nitrate, the result is a cheesy precipitate: HCl + AgNO_3 = AgCl + HNO_3.

The nitrate solution is used, in addition to medicine, in film photography.

If desired, pure metal can be obtained from this nitric acid salt. To do this, you need to carry out electrolysis of a nitrate solution. The electrolysis process is as follows: an aqueous solution of lapis is poured into a bath made of porcelain, ceramics, plastic (not metal), two electrodes (anode and cathode) are lowered into it, and current is supplied to them. In water, metal salts are present in the form of positive and negative ions. Positive ions (metal ions) will be attracted to the negative cathode, i.e. pure silver will settle on the cathode.

Formulas for electrolysis of an aqueous solution of silver nitrate:

1. 4Ag+ + 2H_2O = 4Ag0 + 4H+ + O_2 + 4NO_3- (complete ionic equation).

2. 4AgNO_3 + 2H_2O = 4Ag + 4HNO_3 + O_2 (molecular equation).