Дегидроуксусная кислота

Химические свойства

Dehydroacetic acid is a white to cream-coloured powder that is only very slightly soluble in water (less than 0.1 %). However, the sodium salt hydrate (CSH7Na04.H20) has a solubility of 33% in water at 25°C, and 48% in propylene glycol. The acid is 22% soluble in acetone, 18% in benzene, and I g dissolves in about 35 ml of ethanol.It is used to reduce pickle bloating, and as a pesticide and preservative for squash and strawberries. Its permissible use level is 65ppm.
Dehydroacetic acid is one of the food additives found in red wine and was determined by ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS).
To assay dehydroacetic acid, add 500 mg to a 250-ml Erlenmeyer flask and dissolve in 75 ml of neutral alcohol. Following the addition of phenolphthalein T.S., titrate with 0.1 N NaOH to a pink end-point that persists for at least 30 s. Each ml of 0.1 N NaOH = 16.82 mg of dehydroacetic acid (National Academy of Sciences, 1963).
Dehydroacetic acid is a synthetic chemical (no plant-based preservatives that meet our efficacy standards currently exist) that is considered to be a low hazard for human health and for the environment.

Использование

Dehydroacetic acid (DHS) is used as stabilizer for cosmetic and pharmaceutical products due to its fungicide and bactericide activity, as additive for PVC-stabilizers and for the syntheses of veterinary medicines. Product Data Sheet

Подготовка

1) Dehydroacetic acid is prepared from Ethyl acetoacetate by self-condensation under mildly alkaline conditions (Sodium bicarbonate). 2) by polymerization of Ketene, obtained by thermal decomposition of Acetone).

Общее описание

Dehydroacetic acid is a pyrone derivative, that is typically synthesized by the base-catalyzed dimerization of diketene. It is used as a preservative in pharmaceutical, food and cosmetic products.
Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.

Профиль безопасности

Poison by ingestion. Moderately toxic by intraperitoneal route. Questionable carcinogen with experimental tumorigenic data. Combustible when exposed to heat or flame. When heated to decomposition it emits acrid smoke and irritating fumes.

Растворимость в органика

soluble in most hydrocarbons, but only about 3% soluble in alcohol and about 1.5% in Propylene glycol. Being an acid, it is soluble in aqueous alkali under formation of alkali salt .