CAS N° 87-69-4

DEFINITION
Tartaric Acid contains not less than 99.5 per cent and not more than the equivalent of 101.0 per cent of (2R,3R)-2,3-dihydroxybutanedioic acid, calculated with reference to the dried substance.
Dextrorotatory tartaric acid is the natural diastereoisomer of tartaric acid.
It differs from synthetic tartaric acid because of the value of the angle of optical rotation of light [a] = 12,0° (c = 20 in water).
It is widely present in nature in the juice of many kinds of fruit, both free and combined with potassium, calcium or magnesium.
It was noticed in the past, since its potassium acid salt deposited as crystals during fermentation of wine and was called faecula (little yeast) by the Romans.
In modern processes, the acid potassium tartrate obtained during wine making is first converted into calcium tartrate which is then hydrolised into tartaric acid and calcium sulphate.

IDENTIFICATION
Solution is strongly acid.
Solution gives positive test for tartrate.