What is the Importance of determining the total ash and acid insoluble ash content of drugs Give their possible composition?

Answer 1

The residue left after incirenation of the crude drug is designated as ash. The residue obtained usually represents the inorganic salts naturally occuring in the drug and adhering to it.it varies with in defininte limits according to the soils, it may also include inorganic matter deliberately added for the purpose of adulteration. Hence, an ash value determination furnishes the basis for judging the identity and cleanliness of any drug and gives information relatives to adulteration/contamination with inorganic matter, thus ash values are helpful in determining the quality and purity of drug. The total ash of crude drug reflects the care taken in its preparation. The acid insoluble ash is a part of the total ash that is insoluble in dilute hydrochloric acid. A higher limit of acid-insoluble ash is imposed, especially in cases where silica may be present or where calcium oxalate content of the drug is higher Procedure given in indian pharmacopeia was used to determine the different ash values such as total ash, acid insoluble ash, and water - soluble ash value.

Ash is inorganic residue remaining after the water and inorganic matter have been removed by heating in the presence of oxidizing agents, which provides a measure of the total amounts of minerals within the foods

The acid insoluble ash (AIA) content is the proportion of a sample that is not hydrolyzed by 72% sulphuric acid and is not subsequently volatilized upon the incirenation of this acid insoluble residue.