Acids tannic

Tannic acid Red atoms are oxygen black atoms are carbon and white atoms are hydrogen. 

A kind of ink called iron gall ink is made from tannic acid, iron(ll) sulfate, gum arabic, and water. The recipe for this ink has been known since the Middle Ages. It is used for important documents because it does not wear away easily. 

Tannic acid is mentioned in some very old medical books as a treatment for mushroom poisoning. 

Studies suggest that people allergic to cats may 

Tannic acid is not a true acid because it does not contain the carboxyl group (-COOH) present in all organic acids. Instead, it is a polyphenol, a compound with many ( poly ) phenol (C6H50H) groups. 

Yellowish-white to light brown, amorphous, bulky powder, flakes, or spongy masses faint characteristic odor astringent taste gradually darkens on exposure to air and light dec, 210-215°C.1 

One gram dissolves in 0.35 mL water and 1 mL of glycerol very soluble in alcohol and acetone practically insoluble in benzene, chloroform, ether, petroleum ether, carbon 

Irritant.3 An experimental carcinogen of the liver by subcutaneous route.2,3 

Wear eye protection, laboratory coat, and nitrile rubber gloves. Cover spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. Transfer to an appropriate labeled container for disposal by burning.3 4 

Place in a separate labeled container for recycling or disposal by burning.3 

To the rest of the tea-infusion add a dilute solution of lead acetate, drop by drop, from a pipette as long as a precipitate is formed. 

Devise and carry out an experiment to determine whether the amount of tannic acid present in a tea-infusion is greater when the tea is steeped for 2 minutes, or when it is boiled with water for 15 minutes. 

Put on a piece of cotton cloth some of the iron ink and on another piece some ordinary ink which probably contains a dye. When the ink-spots are dry, cut each piece of cloth into three parts in such a way that the pieces containing the iron ink can be distinguished from those containing the dye. Wash the pieces in water. Add a piece of each kind to a dilute solution of oxalic acid. Explain the result. Add a piece of each kind to a dilute solution of sodium hypochlorite. Place these pieces alter- 

—(b) The formation of insoluble compounds from tannic acid and the salts of metals is used in preparing mordants in dyeing. (See experiment 228, page 191.) 

---

Burns caused by dry heat (e.g., by flames, hot objects, etc.). For slight bums in which the skin is not broken, apply tannic acid jelly ( Tannafax ), acriflavine jelly ( Bumol ) or butesin picrate ointment (butesin is re-butyl J aminobenzoate). 

Tannic acid dissolve 1 g tannic acid in 1 mL alcohol and make up to 10 mL with water. 

Minerals, particularly Bentonite, ate used to remove proteins that tend to cause haze in white wines. The natural tannin of ted wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyttohdone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen ate often used to fine ted wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

The pomegranate alkaloids, pelletierine (46) and pseudopelletierine (48) as well as minor accompanying bases, have a long history as salts of tannic acid as an anthelmintic mixture for intestinal pinworms (see Antiparasitic AGENTS, ANTHELMINTICS). The alkaloids themselves (as the taimates) are obtained from pomegranate tree (Punkagranatum L.) root bark and are among the few bases named after an individual (P. J. Pelletier) rather than a plant. 

Tannate Complexation. Certain dmgs, those that contain amine groups, complex readily with tannic acid. Such complexes release the dmg gradually and uniformly. The rate seems to be affected by the pH and the electrolytes present in the gastrointestinal tract. At lower pH, the dmg is released more quickly. Other complexing compounds have also been used. 

Association Complexes. The unshared electron pairs of the ether oxygens, which give the polymer strong hydrogen bonding affinity, can also take part in association reactions with a variety of monomeric and polymeric electron acceptors (40,41). These include poly(acryhc acid), poly(methacryhc acid), copolymers of maleic and acryflc acids, tannic acid, naphthoHc and phenoHc compounds, as well as urea and thiourea (42—47). 

Several stabilization agents are available, ie, protolytic enzymes, tannic acid, or various adsorbents such as polyvinylpyrroHdinone (PvPP) and nylon-6,6 or bentonite. The stabilizing agent is normally added during the transfer to the stabilizing tank and left for some hours to react. 

Astringents are designed to dry the skin, denature skin proteins, and tighten or reduce the size of pore openings on the skin surface. These products can have antimicrobial effects and are frequendy buffered to lower the pH of skin. They are perfumed, hydro-alcohoHc solutions of weak acids, such as tannic acid or potassium alum, and various plant extracts, such as bitch leaf extract. The alcohol is not only a suitable solvent but also helps remove excess sebum and soil from the skin. After-shave lotions generally function as astringents. 

Many fluids of natural origin contain detectable quantities of high molecular weight organic anions, such as those from humic, fulvic, and tannic acids, which can be carried to and deposited on AX membranes. Such deposits can behave as thin films partially selective to cations (6). The iaterfaces between such films and the undedyiag AX membranes then act as very thin stagnant depletion compartments and the AX membranes may exhibit polarization at current densities that are much lower than would be expected for new membranes ia the abseace of such anioas. 

Gerbsaure /. tannic acid. -Idsung, /. tannic acid solution, -messer, m. tannometer, bark-ometer. 

Gerbstoff, m. tanning principle, tanning matter, tan specif., tannic acid, tannin. 

Kino, n. motion pictures, cinema motion-picture theater kino, -gerbsaure, /. kino-tannic acid, -maschtne, /. motion-picture machine, -tinktur, /. tincture of kino. 

QuatemarstaU, m. quaternary steel. Quebrachit, n. quebrachitol, quebrachite. Quebracho-gerbsaure,/. quebracho tannic acid. 

Preparation of Alkaloid III Tannate 20 g of Alkaloid III was dissolved in 200 ml of isopropyl alcohol at room temperature and a mixture of 30 g of tannic acid dissolved in 300 ml of isopropyl alcohol, maintained at 40 to 50 C was added thereto with rapid stirring. The mixture was cooled to 20 C, filtered and the precipitate dried at about 80 C. There was thus obtained 33.5 g of the tannate salt of Alkaloid III, as a pale yellow amorphous powder, relatively insoluble in water, and having an indefinite melting point. 

Structural Formula A complex of amphetamine, C HsCHjCHlCHsiNHj and tannic acid Chemical Abstracts Registry No. 1407-85-8... 

Approximately 75 grams of d-amphetamine as a free base was dissolved in 300 ml of isopropanol (solution A). Approximately 200 grams of NF tannic acid was dissolved in 700... 

---