Determination of Ash value

Aim: Determination of Ash value.

Requirement : Desiccator, muffle furnace, Silica crucible, Tong, digital balance, heat resistant gloves.

Principle: The residue remaining after incineration is the ash content of the drug (inorganic carbohydrates, phosphates, silicates of sodium, potassium, calcium and magnesium).

1. Put a silica crucible in muffle furnace and heat it to redness for 10 min.
2. Allow to cool in desiccator and weigh.
3. Now, take 2 grams of powdered crude drug in silica crucible.
4. Again put in muffle furnace and ignite it to 400-600 degree Celsius so, that powdered drug changes to white ash or nearly white ash.
5. Then, put it in desiccator to avoid any moisture or impurity.
6. weigh the powdered dry or ash content again.

Observation : Weight of empty silica crucible = 35.93 gram weight of powdered crude dong = 2.0 gram weight of silica crucible with ash = 36.08 gram

Weight of ash = Weight of silica crucible with ash – Weight of empty Silica crucible
= ( 36.08 – 35.93 ) gram
= 0.15 gram

Ash value of 2 gm of powdered crude drugs = 0.15 gm. Therefore, ash value of 100 gram of crude drug = 0·15/2 x 100 = 7.5 %
Percentage(%) Ash value = 7.5.%.
Result: The ash value of crude drug was found to be 7.5.%.