Copper

COPPER (symbol Cu), chemical element, atomic number 29; atomic weight 63.57, specific gravity 8.93; melting point 1,083°; belongs to the group of metals. In nature, Cu is sometimes found in pure form (native copper), but more often in compounds forming copper ores. The most important of these are: red copper ore (Cu₂O), black copper ore (CuO), malachite, and copper azure. Cu is often found in the form of sulfide compounds together with iron, such as copper pyrite, variegated copper ore, and others. In dry air at ordinary temperature, Cu does not oxidize, but in ordinary air containing moisture and CO₂, it oxidizes, turns brown, and becomes covered with a green layer of basic carbonate salts known as verdigris.-Cu forms two series of compounds: cuprous, in which it is monovalent, and cupric, where it is divalent.-Cu is found in the animal organism: in the plumage of some birds, in the blood pigment of mollusks (hemocyanin), and in humans in the liver and other organs. Cu acts destructively on many lower plant organisms-fungi and algae, some of which parasitize cultivated plants, for example, on grapevines, apple trees, and others; therefore, to combat such parasites, a solution of copper salt is used by spraying infected trees. Salts of Cu have different effects on various bacteria: thus, according to experiments by Buchholz, many of their species cease to multiply in a 1% solution of copper sulfate, but for example, according to experiments by other authors, the tubercle bacillus does not lose its virulence after remaining for several days in a 1% solution of copper chloride; according to experiments by Feld, the copper salt cation can generally have an effect on the tubercle bacillus only in a protein-free nutrient medium; spores of anthrax do not die after 10 days of exposure to a 5% solution of copper sulfate and 20 days to a 10% solution of copper chloride. On the tissues of the animal organism, soluble copper salts act in high concentrations as a caustic agent, and in lower concentrations as an astringent, since they precipitate proteins from their solutions. Copper salts, when administered per os, have an unpleasant metallic astringent taste, irritate the gastric mucosa, and quickly cause reflex vomiting, with the greater part of them being excreted along with the vomit. Due to the rapid onset of vomiting, acute poisoning with copper salts usually does not occur, and it is observed only in rare cases when a large amount of copper salt is introduced, part of which manages to pass into the intestine and causes damage to its mucosa, accompanied by severe diarrhea, sometimes bloody, with sharp abdominal pains. The vomit is usually colored blue or green by the copper salt, and sometimes crystals of the salt are found in it. After vomiting and diarrhea in acute poisonings, collapse occurs with weakening of respiration and falling pulse, with loss of consciousness and comatose state, during which asphyxial convulsions appear, ending in death from paralysis of respiration. These symptoms of poisoning are caused not by the resorptive action of Cu, but are the result of local lesions of the gastrointestinal tract and the associated strong reflex effect on the central nervous system and heart. If in acute poisoning death does not occur within the first 24 hours, the victim dies after several days from general exhaustion with symptoms of heart paralysis. In such cases, a sharp decrease in urination or even anuria is also observed, and often jaundice. This is explained by the fact that due to damage to the gastrointestinal mucosa, the absorption of Cu is enhanced, which, when excreted through the kidneys and liver, causes damage to them, which is not observed in cases of early death when Cu has not had time to be absorbed. More common subacute poisonings with copper salts are generally characterized by the same symptoms: first by severe vomiting and diarrhea with abdominal pains, but the symptoms of collapse are less pronounced; later, kidney and liver diseases are usually observed, as in acute poisonings, with late death. The metallic taste in the mouth remains for a very long time, and cases have been described where after such poisonings, the sight of a copper object caused the same sensation in the mouth, even vomiting, which indicates the development of a conditioned reflex reaction to Cu. Long-term administration of small doses of Cu and its compounds per os, as shown by experiments on animals and humans, either leads only to weakly expressed symptoms of local action or is not accompanied by any pathological phenomena. Thus, Galip, administering per os to a dog weighing 8 kg 5 mg of copper salt daily for 120 days, observed no other symptoms in it except for occasionally occurring attacks of vomiting and diarrhea. The same author for 14 months used for his food prepared in unlined copper vessels containing compounds of Cu, and noticed no signs of poisoning in himself. Other researchers (Rademacher, Toussaint) daily for several months took copper oxide in doses of 0.24-0.5 and copper sulfate in doses of 0.04-0.07 without any noticeable harm to health. On the basis of such experiments, repeatedly carried out by other researchers, all authors except Harnack recognize that in chronic poisoning with pure Cu and its compounds, the resorptive poisonous action of Cu does not manifest. Of those symptoms that characterize professional diseases in various copper productions (see below), some may be the result of the local action of Cu. The resorptive poisonous action of Cu can be observed only in experimental poisoning of animals by administering to them subcutaneously or better intravenously weakly dissociating copper salts of organic acids, which do not cause blood clotting. In this case, in warm-blooded animals, symptoms of poisoning first appear in the form of weakening and difficulty of voluntary movements due to disease of the peripheral nerves, and then complete paralysis of the striated muscles develops, soon spreading to respiratory and cardiac functions, with the heart stopping later than respiration. If the animal does not die soon after poisoning, it develops severe diarrhea, often bloody, due to the excretion of Cu through the intestine. In addition, in such cases, the urine contains protein, sometimes Hb and blood elements as a result of kidney damage by Cu being excreted through them. Absorbed Cu is excreted from the body with urine, bile, through salivary and intestinal glands, while some of it is retained in the body, mainly in the liver and to a lesser extent in the spleen, kidneys, and thyroid gland. First aid in poisoning-see Poisoning. For therapeutic purposes, Cu is administered internally as an emetic, which acts quickly (within 5-10 min.), without causing preceding phenomena of nausea. In phosphorus poisoning, copper sulfate is at the same time an antidote due to the fact that it oxidizes phosphorus into relatively harmless phosphoric acid, and in addition, being reduced to cuprous Cu in this process, it coats the pieces of phosphorus with a thin layer, delaying their absorption. Externally, copper salts are used in solutions of low concentration (up to 1%) as an astringent, while in crystalline form some copper salts are used as a caustic agent, with the astringent action of copper salts being accompanied by vasoconstriction, while caustic concentrations cause their dilation.-Cu and some of its derivatives in the colloidal state, as well as some of its complex compounds, apparently have a therapeutic effect in various forms of tuberculosis. The therapeutic effect obtained in this way is explained not by the etiotropic action of such compounds, since they have minimal parasitotropic properties, but by the fact that, having a special affinity for pathological tissues, they are retained in the foci of the disease and have a stimulating effect on the normal tissue bordering them, whereby these foci are surrounded by connective tissue. The application of some of its preparations in cancer diseases is also based on the affinity of similar copper compounds for pathological tissues.-Copper sulfate in very high dilution, for example 1:1-3 million parts of water, is used to stop the growth of algae in bodies of water that give the water an unpleasant odor and taste. The same salt was tried to be used for disinfecting water infected with typhoid bacilli, but since this requires a higher content of copper salt in the water, this method of water purification has not become widespread.

For detection in solutions, as well as in urine, the following reactions can be used: 1) The liquid being tested is slightly acidified with acetic acid and drops of a 5% solution of yellow blood salt are added; this forms a colloidal ferrocyanide of copper, which colors the liquid a red-brown color of varying intensity depending on the amount of copper in the solution being tested. 2) A freshly cleaned iron or zinc plate with sandpaper is immersed halfway into the liquid being tested; after some time (the later, the sharper the reaction), a red deposit of metallic copper appears on the plate. Preparations. Cuprum aceticum, the average acetic salt, bluish-green crystals soluble in 14 parts water, 16 parts alcohol; used externally as a powder as a mild cauterizing agent for mucous membranes, as an astringent - in the form of an eye ointment (2%) and in solution (0.5%) for douches in urethritis and vaginitis; internally (according to French authors) - in pediatric practice for scrofula and tbc in doses of 0.01-0.04 per dose. - Cuprum subaceticum (Aerugo), basic copper acetate, a thin green powder or amorphous pieces of bluish-green color; not completely soluble in water; externally - as a powder for cauterizing ulcers prone to proliferation, or in the form of an ointment and plaster. In technology it serves as a paint, which often turns out to be very poisonous due to arsenic impurities in it. The question of using basic copper acetate for coloring vegetables green, usually prohibited by legislation as harmful to the health of consumers of such canned goods, was the subject of special investigations, especially in France, where this method is widely spread (verdissage). Although direct harm from the amount of copper introduced into the body cannot be proven, it is nevertheless believed that at a certain concentration it can have an inhibitory effect on enzymatic digestive processes, therefore in France it was established by decree that the amount of this dye should not exceed 0.1 in 1 liter of coloring liquid. - Cuprum alumina-turn, syn. Cuprum sulfuricum aluminatum (Lapis divinus), eye stone, a fusion of 16 parts copper sulfate, 16 parts potassium nitrate salt, 17 parts alum and 1 part camphor; amorphous pieces of pale green color, camphor odor; dissolve in 16 parts water, forming a turbid solution of greenish color; applied in substance in the form of sticks for cauterizing in conjunctivitis, in the form of eye powder (1 part to 2-5 parts sugar), in solution for eye drops (0.2-0.4 : 100.0). - Cuprum bichloratum, cupric chloride, CuCl₂+2H₂O, green rhomboid hygroscopic crystals, soluble in water and alcohol; internally - as an alterans and tonic for scrofula, rickets and skin diseases based on nutritional disorders. - Cuprum citricum (Cuprocitrat, Cuprocitrol), copper citrate (ФУП) (Cu₂C₆H₄O₇)₂+5H₂O, light green crystalline powder, almost insoluble in water; externally - in the form of 5-10% ointment for trachoma. - Cuprum nitricum, copper nitrate, Cu(NO₃)₂+3H₂O, blue crystals, easily soluble in water, hygroscopic; used externally, like Cupr. sulfuricum. - Cuprum sulfo-carbolicum (phenolsulfonicum), para-phenolsulfonic copper salt; green prismatic or needle-shaped crystals, soluble in water; externally - in 1-2% solution as an antiseptic and astringent in surgical practice; 0.1 - 0.5% solution - for douches in gonorrhea. Cuprum sulfuricum, copper sulfate, blue vitriol (ФУП), CuSO₄+5H₂O, blue transparent crystals or blue crystalline powder; dissolves in 25 parts water, at 200° loses crystallization water, turning into a white powder; internally - as an emetic and in phosphorus poisoning in doses of 0.25 for adults, 0.05-0.1 for children every 10 minutes until vomiting occurs or in the form of a single dose of 0.5 (!) for adults; externally - 0.1-0.2% solution in subacute and chronic conjunctivitis and for douches in urethritis and vaginitis; in substance (Bacillus cupri sulfurici) - for cauterizing mucous membranes, especially the conjunctiva. - Cuprum sulfuricum crudum, crude copper sulfate; 5-10% solution for deodorization and disinfection of cesspools and garbage pits, garbage dumps, etc. - Elektro-sirgol, a solution of colloidal copper, obtained electrically; contains 0.15 g copper in 1 l; used in cancer and tbc intravenously, starting with 2 cm³ and gradually reaching up to 10 cm³, or intramuscularly 5-10 cm³. - Cuprase, a colloidal solution of copper hydrate; sold in ampoules of 5 cm³, containing 1.2 mg copper each; subcutaneously - in cancerous diseases. - Cuprex, a solution of organic copper compound; used externally against pediculosis in humans and domestic animals. - Cuprol, a protein compound of copper; externally - 1-5% solution in trachoma. - Sirgonat, a protein compound of copper, sold in tablets containing 9.4 mg copper each; 1-2 tablets 3-5 times a day, for children - half dose, in acute intestinal diseases of infectious nature and in various kinds of worms; due to the possibility of vomiting, it should not be administered on an empty stomach. - Lekutyl, a compound of lecithin and copper citrate, dark green powder, soluble in ether and chloroform; externally - in the form of 5% ointment (the ready-made 'Lekutyl-salbe' contains 10% local anesthetic cycloform) and internally - in the form of ready-made pills; used in lupus and surgical tbc.

M. Likhachev. Copper as an industrial poison. In its pure form, copper is rarely used in industry; alloys with various metals and chemical compounds are widely used. Among alloys, the most important are bronze (an alloy of copper with 10-22% tin), phosphor bronze (the same with the addition of 0.5-2.0% phosphorus), brass (an alloy of copper and zinc in various proportions; for example, tombac contains 85% copper, while in white brass it is 50% copper, etc.), nickel silver (an alloy of copper, nickel, zinc or tin) and others. Among chemical compounds, mention should be made of the oxides and suboxides, copper sulfate, basic copper acetate (verdigris), Brunswick green, Bremen green, copper sulfide and others. Under industrial conditions, copper can enter the bodies of workers in two ways: through the gastrointestinal tract and through the respiratory tract. However, absorption by this route is extremely slow, and copper enters the workers' bodies in very small amounts. There is no firmly established opinion regarding the toxicity of copper. While relatively large amounts of copper, when entering the gastrointestinal tract, can cause more severe acute poisoning phenomena, there are no data on poisoning of workers under industrial conditions. In workers who have to work in conditions where large amounts of copper dust are present, inflammation of the gums, a green border on the edges of the gums, and discoloration of the teeth in the same color have been found; further cases of hair discoloration green have been described. Data on copper poisoning of workers given in the old literature (a summary is given by Laihe), which speaks of a number of nervous symptoms, can quite be attributed to the action of lead or arsenic, which are often found in copper alloys, and therefore most modern toxicologists (Lewin, Lehmann, Toussaint) believe that copper is not an industrial poison. As for the question of a specific professional disease—foundry fever, which is observed very frequently in workers engaged in brass casting, the cause of this disease is not the inhalation of copper, but zinc oxide, which is released during melting in the form of the finest dust (colloidal suspension) (see Foundry fever). Of great interest is the 31 cases of copper-mordant fever published in 1930, described by Brodsky, Belkin and Kurbatov (North Caucasian Institute for Labor Protection). The disease was observed in workers engaged in grain mordanting, for which the powder 'fungicide' was used; its main component is basic copper carbonate with an admixture of copper sulfate, no other metals were found in it. The room where mordanting is carried out is heavily dusty (41-53 mg of dust per 1 m³ of air). The disease in its onset, course and outcome very much resembles attacks of foundry fever (chills, elevated temperature, profuse sweating, in a number of more severe cases—nausea, vomiting of green masses, weak rapid pulse, etc.). The authors attribute the disease without question to the inhalation of the mordant powder, which is present in the air in the form of the finest dust. If these observations are confirmed by experimental research, the question of the possibility of developing an intoxication of the foundry fever type as a result of inhaling copper will receive new light. Among other hazards when working with copper, it is necessary to note: unfavorable working conditions in foundries (high temperature, radiant energy, air pollution with dust, CO, etc.), aggravated by the fact that copper casting is usually carried out in small rooms, the release of fine sharp-pointed dust in a number of processes (preparation and use of powder for bronzing, processing and finishing of brass objects), the danger of phosphorus poisoning in the manufacture of phosphor bronze (yellow phosphorus is often added), the release of poisonous gases in the preparation of copper chemical preparations (nitrogen oxides, and possibly arsine). Prevention: proper arrangement of foundries, with mechanization of production processes, transition to electric melting and proper ventilation. Very good results were obtained, for example, after the reconstruction of the largest copper foundry at the 'Krasny Vyborg' plant (in Leningrad), where as a result of rationalization, cases of foundry fever disappeared and the number of burns decreased. In processes accompanied by the release of dust and harmful gases, sealing of equipment and local ventilation.

N. Roaenbaum. Detection in non-forensic cases. Objects for examination for copper can be internal organs, vomit, green vegetable preserves, to which copper is added to preserve the green color. Due to the widespread distribution of copper and its possible accumulation in the liver of elderly people, the finding of small amounts of copper in the internal organs of a corpse and even large amounts, for example in the liver in cirrhosis, by itself does not indicate poisoning and always requires quantitative determination and comparison with all the circumstances of the case. After the destruction of the organic matter of the internal organs (see Poisons, isolation), the liquid is saturated with H₂S. The metal sulfides together with the sulfur precipitate and organic substances (after destruction by chlorine) are treated with ammonium polysulfide and aqueous ammonia; if a black residue is present, it is treated with nitric acid, mixed half and half with water. In this case, copper sulfide dissolves. The liquid is diluted with water and filtered. Part of the filtrate is mixed with ammonia: blue coloration. To part of the filtrate, neutralized with ammonia and acidified with acetic acid, a few drops of a solution of yellow blood salt (potassium ferrocyanide) are added: red coloration and red precipitate with large amounts of copper. When examining green vegetables, they are dried, incinerated, and in the hydrochloric acid extract of the ash, copper is detected by the above reactions. For quantitative determination of copper, it is precipitated by hydrogen sulfide, the precipitate is washed with hydrogen sulfide water, dissolved in nitric acid (diluted with two volumes of water), and the filtrate is evaporated in a weighed crucible, calcined, and the copper oxide is weighed. For volumetric determination, the sulfuric acid solution of copper sulfide is evaporated to dryness, the residue is dissolved in normal sulfuric acid solution (in a bottle with a ground stopper), potassium iodide and a 10% solution of ammonium thiocyanate are added. The iodine liberated is titrated with ^p/₁₀ or p/₁₀₀ solution of sodium thiosulfate (indicator - starch paste). Two equivalents of copper (Cu) correspond to one equivalent of iodine (J): CuS0₄+2KJ -+ CuJ₂ + K₂S0₄; CuJa tf: CuJ +J; CuJ + KCNS-» CuCNS + KJ. A. Stopanoi.