Determination of Total Ash content, Acid insoluble Ash content and Water soluble Ash content

1. By
Mrs. Poonam N. Chougule
Assistant Professor and HOD of Pharmacognosy
department
AMCP, Peth- Vadgaon.

2.  Materials Required- Silica crucible, desiccators, ash less
filter papers, dilute HCl, powdered crude drug.
 Principle- Ash values are helpful in determining the
quality and purity of crude drugs especially in the
powdered form.
 The object of ashing vegetable drugs is to remove all
traces of organic matter which may otherwise interfere
in an analytical determination.
 On incineration, crude drugs normally leave and ash
usually consisting of Carbohydrates, phosphates and
silicates of Sodium, Potassium, calcium and
magnesium.

3.  The total ash of crude drug reflect the care taken in its
preparation. Acid insoluble Ash is the Residue left after
extracting total Ash or sulphated Ash with HCl, while water
soluble Ash represents that part of total Ash which is a
soluble in water.
 Water soluble Ash is good indicator of previous extract of
water soluble components of the crude drug, it is a reflex
on incorrect preparation or processing of crude drugs.
 Acid insoluble Ash is indicating of siliceous or earthy
material contamination of crude drugs. a higher limit of
acid insoluble Ash is imposed, especially in cases where
silica may be present or when the calcium oxalate content
of the drug is very high. some analyst favor mixing of
sulphuric acid with powder drug before ashing and this
sulphated Ash is normally less fusible than ordinary Ash.

4. 1. Weigh accurately about 3 gram of powder the drug in
tarred silica crucible .
2. To incinerate the powdered drug by gradually
increasing the heat by using muffle furnace until free
from carbon and cool, keep it in desiccators.
3. Weigh the Ash and calculate the percentage of total
Ash with reference to the air dried sample.

5. 1. Boil the total Ash obtained as above for 5 minutes
with 25ml of dilute hydrochloric acid.
2. To filter and collect the insoluble matter on ashless
filter paper, wash the filter paper with hot water , and
ignite in tarred crucible cool and keep in desiccators.
3. Weigh the Residue and calculate acid insoluble Ash
of liquorices with reference to the air dried drug.

6. 1. The total Ash obtained as above with the 25 ml of water
for 5 minutes.
2. To filter through ashless filter paper.
3. Wash the Residue with hot water and then Ignite in the
tarred silica crucible by muffle furnace cool and keep in
desiccators .
4. for with Ash obtained after inspiration and calculate
water soluble Ash of drug with reference to the air dried
sample.
 The unpeeled variety of liquorice root should contain
not more than 10% of total Ash and 2.5 % of acid
insoluble Ash.

7. 1. Total Ash value of liquorice root powder drug is :
2. To acid insoluble Ash value of liquorice root powder
drug :
3. Water in soluble Ash value of liquorice root powder
drug: