1. Determination of Ash content

2. Definition
Ash Value
The residue remaining after incineration is the ash content of the drug.
Inorganic salts of carbonates, phosphates, silicates of sodium, potassium, calcium and magnesium.
Ash value is a criterion to judge the identity OR purity of the crude drug.
A high ash value is indicative of contamination, substitution, adulteration or carelessness in preparing the crude drug for marketing

3. Ash value
Physiological Ash: Which is derived from the plant tissue itself
Non – physiological Ash: Which is the residue of the adhering material to the plant e.g. Sand and soil.

4. Ash value Ash value can be determined by three different methods:
Total Ash
Total ash method is used to measure the total amount of material remaining after incineration
Acid insoluble Ash
Acid insoluble ash is the residue obtained after boiling the total ash with dil. HCl and igniting the remaining insoluble matter.
Water soluble Ash
Water soluble ash is the difference in weight between total ash and residue after treatment of total ash with water.

5. Heat at 450°C until free from carbon
Total Ash
Weigh accurately about 3gms of the powdered drug in a tared silica crucible
Heat at 450°C until free from carbon
Cool and weigh

6. Acid insoluble ash Total Ash Add10 mL 3N HCL and boil for 5 mins
Filter through ashless filter paper
Ignite at 450 C°
Cool and weigh

7. Water soluble ash Total Ash Add10 mL water nas boil for 5 mins
Filter through ashless filter paper
Ignite at 450 C°
Cool and weigh