Download Determination of Ash

Determination of Ash content
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.
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.
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.
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
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
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