Nomenclature
CAS number: 76-03-9
2,2,2-Trichloroacetic acid; TCA.
C
2HCl
3O
2; mol wt 163.39.
C 14.70%, H 0.62%, Cl 65.10%, O 19.58%.
CCl
3COOH.
Description and references
Prepd by oxidation of chloral hydrate with
nitric acid: Parkes, Hollingshead, Chem.
Ind. (London) 1954, 222. Manuf by chlorination
of acetic acid: Eaker, US 2832803 (1958 to Monsanto). Toxicity study: G. W. Bailey,
J. L. White, Residue Rev. 10, 97 (1965).
Properties
Very deliquesc crystals; slight characteristic
odor. d461 1.629; mp 57-58°; bp 196-197°. Very sol in water, alcohol, ether; dec by heating with caustic
alkalies into chloroform and alkali carbonate. pKa ≈0.7. pH of 0.1 molar aq soln
1.2. Corrosive. Keep tightly closed in a
cool place. Storage of trichloroacetic acid solns in water
of less than 30% strength is not recommended. Decompn products are
chloroform, hydrochloric acid, carbon dioxide and carbon monoxide.
LD50 orally in
rats: 5000 mg/kg (Bailey, White).Derivative
Ethyl ester.
Nomenclature
CAS number: 515-84-4
Ethyl trichloroacetate.
C
4H
5Cl
3O
2; mol wt 191.44.
C 25.10%, H 2.63%, Cl 55.56%, O 16.71%.
Properties
Clear liq; odor resembling menthol. d420 1.383. bp 168°. nD20 1.4507. Insol in water. Misc with alcohol, ether.Derivative
Sodium salt.
Nomenclature
CAS number: 650-51-1
Sodium trichloroacetate; Konesta (Akzo); Varitox (M & B).
C
2Cl
3NaO
2; mol wt 185.37.
C 12.96%, Cl 57.38%, Na 12.40%, O 17.26%.
Properties
Yellow deliquesc powder, mp >300°. Soly in water at 25°: 1.2 kg/l.
Sol in ethanol.Caution
Potential symptoms of overexposure
are irritation of eyes, skin, nose, throat, respiratory system; cough,
dyspnea, delayed pulmonary edema; eye and skin burns; dermatitis;
salivation, vomiting, diarrhea. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140,
1997) p 314.Use
As a decalcifier and fixative in microscopy; also
as a precipitant of protein, esp in albumin detection. As herbicide.
Therapeutic Category
Caustic.
Therapeutic Category (Veterinary)
Caustic, vesicant.