トリクロロ酢酸

外観

無色澄明の液体

溶解性

水及びエタノールと任意の割合で混和する。

解説

トリクロロ酢酸，潮解性結晶．融点54.58 ℃，沸点197 ℃．水，エタノール，エーテルに易溶．水溶液は強い酸性を示す．熱水および塩基性水溶液中で分解してクロロホルムを生じる．いぼを取り除くための局所収れん腐食薬，タンパク質の沈殿剤，除草剤，腐食剤，化学試薬などに用いられる．皮膚を腐食する．有毒．

森北出版「化学辞典（第2版）

用途

除タンパク剤、腐食剤 (有機化合物辞典 (1985))

用途

除たん白剤、変成剤、脱灰液調製用。

用途

マロンジアルデヒドの定量試液、除たん白剤等。

用途

生体成分分画剤、除たん白剤。

用途

顕微鏡標本作成のための骨等の脱カルシウム剤。

効能

収斂薬

製造

酢酸を塩素化するか，加熱した抱水クロラールに発煙硝酸を作用させると得られるトリクロロ酢酸．

使用上の注意

潮解性がある。

説明

Trichloroacetic acid, also known as TCA or 76-03-9, is a colorless or white orthorhombic crystal with strong deliquescence and a slight, special irritant smell. It is highly corrosive. TCA's aqueous solution is strongly acidic, with a pH of 1.2 for a 0.1 mol solution. Concentrations of TCA at or below 30% cannot be stored for long periods due to decomposition into chloroform, hydrogen chloride, carbon dioxide, and carbon monoxide. Dilute alkali leads to hydrolysis into chloroform and carbon dioxide. Concentrated alkali results in the formation of formic acid. TCA is a highly toxic substance with an oral LD50 of 3320mg/kg.

化学的特性

Trichloroacetic acid, a colorless crystalline solid, is commonly utilized in liquid solutions. It has the ability to absorb moisture from the surrounding air and become syrupy. When dissolved in water, the process releases heat. However, this potent acid is corrosive to both metals and tissue.

使用

Protein precipitation reagentTrichloroacetic acid is used as a precipitating agent in biochemistry for precipitation of proteins, DNA and RNA. It is an active ingredient used in cosmetic treatments like chemical peels, tattoo removal and the treatment of warts including genital warts. It is also used to determine protein concentration and as a decalcifier and fixative in microscopy.

定義

ChEBI: Trichloroacetic acid is a monocarboxylic acid that is acetic acid in which all three methyl hydrogens are substituted by chlorine. It has a role as a metabolite, a carcinogenic agent and a mouse metabolite. It is a monocarboxylic acid and an organochlorine compound. It is functionally related to an acetic acid. It is a conjugate acid of a trichloroacetate.

主な応用

Trichloroacetic acid(76-03-9) can be used as pharmaceutical raw materials, herbicides (potassium trichloroacetate and sodium trichloroacetate, etc.), textile dyeing auxiliaries, metal surface treatment agent and acid chloride, anhydride, amide, polyester, organometallic salt, water salicylaldehyde, chlorocarboxylic acid and the raw materials of other organic synthesis.
In addition, in medicine, it can also be used as etherifying agents and keratolytics, bile pigment reagents and protein precipitation reagents. In the field of biochemistry, it can be used for separation analysis of biological phosphate compounds and reagents for determination of fluoride and lipid as well as microscopic fixative, decalcification, chromatography reagents.
The product is warts agent and astringent in pharmaceutical field, mainly used as biochemical drug extractant for the extraction of many highly efficient drugs such as adenosine triphosphate, cytochrome C and placental polysaccharides.
In addition, trichloroacetic acid, together with alkaline phenol, can be used for salicylaldehyde compound synthesis by ReimerTiemann reaction. It can also react with monoolefine compounds for synthesizing chlorocarboxylic acid [CCl3 (CH2CH2) nCOOH].

反応性

Trichloroacetic acid is a strong organic acid with a dissociation constant K = 3 × 10-2. It has lively chemical properties. Its sodium salt is easily subject to decarboxylation into chloroform. It will be reduced to alcohol upon coming across LiAlH4. It can have halogen replacement reaction with KBr:

一般的な説明

Trichloroacetic acid (TCA) is derived from Trichloroethylene (TCE) metabolism. It is used as an acid decalcifying agent. TCA is used as a fixative for nuclear staining and protein precipitation.

反応プロフィール

Trichloroacetic acid is a strong acid; when heated, in the presence of water, decomposes forming phosgene and HCl. [Handling Chemicals Safely 1980 p. 915]. The acid was added to copper wool and rinsed down with dimethyl sulfoxide. This caused what was thought to be an extremely exothermic dehydrohalogenation reaction that melted the neck of the flask, [Chem. Eng. News, 1981, 59(28), 4].

健康ハザード

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

火災危険

Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

安全性プロファイル

Poison by ingestion and subcutaneous routes. Moderately toxic by intraperitoneal route. Questionable carcinogen with experimental carcinogenic data. Experimental reproductive effects. Mutation data reported. A corrosive irritant to skin, eyes, and mucous membranes. When heated to decomposition it emits toxic fumes of Cland Na2O. Used as an herbicide.

職業ばく露

This haloacetic acid can be a byproduct of drinking water disinfection and may increase the risk of cancer. Trichloroacetic acid is used as medication; in organic syntheses; as a reagent for albumin detection; as an intermediate in pesticide manufacture and in the production of sodium trichloroacetate which is itself a herbicide.

発がん性

TCA was not mutagenic in bacterial assays.The IARC has determined that there is limited evidence for the carcinogenicity of TCA in experimental animals and that it is not classifiable as to its carcinogenicity to humans. Neutralized TCA was not clastogenic in human lymphocytes in vitro or in the mouse bone marrow micronucleus test.

輸送方法

UN1839 (solid) & UN2564 (solution) Trichloroacetic acid, solid and Trichloroacetic acid, solution, Hazard class: 8; Labels: 8-Corrosive material.

純化方法

Purify the acid by fractional crystallisation from its melt, then crystallise it repeatedly from dry *benzene and store it over conc H2SO4 in a vacuum desiccator. It can also be crystallised from CHCl3 or cyclohexane, and dried over P2O5 or Mg(ClO4)2 in a vacuum desiccator. Trichloroacetic acid can be fractionally distilled under reduced pressure from MgSO4. Layne, Jaffé and Zimmer [J Am Chem Soc 85 435 1963] dried trichloroacetic acid in *benzene by distilling off the *benzene-water azeotrope, then crystallised the acid from the remaining *benzene solution. Manipulations should be carried out under N2. [Toxic vapours, use a well ventilated fume cupboard.] [Beilstein 2 IV 508.]

不和合性

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, silver salts, strong acids, strong bases, moisture, iron, zinc, aluminum. Corrosive to iron, steel and other metals.

参考文献

https://pubchem.ncbi.nlm.nih.gov/compound/trichloroacetic_acid#section=Top
https://en.wikipedia.org/wiki/Trichloroacetic_acid