DETERMINATION OF TOTAL ASH VALUE FOR GIVEN CRUDE DRUG SAMPLE (ASHWAGANDHA)

 PHARMACOGNOSY AND PHYTOCHEMISTRY – I PRACTICAL

DETERMINATION OF TOTAL ASH VALUE FOR GIVEN CRUDE DRUG SAMPLE (ASHWAGANDHA)

EXPERIMENT NO.08

Aim: Determination of ash value for given crude drug sample.

Reference: 1. Mayur R. Bhurat, Md. Rageeb Md. Usman, Sanjay A. Nagdev, Practical Pharmacognosy & Phytochemistry – I, Published by S. Vikas And Company (Medical Publisher) page. No. 59, 60.

2. Dr. K.R Khandelwal, Textbook of Practical Pharmacognosy, Published by Nirali Prakashan, Sixth Edition, page. No. 23.8 – 23.9

Requirements:

Apparatus: Forceps, Platinum or Silica crucible with lid, Ash less filter paper, etc.

Chemicals: Crude drug sample, HCI, ete.

Instrument: Mutfle Furnace, Digital balance, Desiccator, etc.

Theory:

Ash values:

The residue remaining left after incineration (complete burn) of the crude drug is considered as ash.

Ash contains inorganic radicals like phosphates, carbonates and silicates of sodium, potassium, magnesium, calcium etc. These are present in definite amount in a particular crude drug hence, quantitative determination in terms of various ash values helps in their standardization. Sometimes, inorganic variables like calcium oxalate, silica, carbonate content of the crude drug affects ‘Total ash value’. Such variables are removed by treating with acid (as they are soluble in hydrochloric acid) and acid insoluble ash value is determined e.g. Rhubarb, Liquorice etc. Used to determine foreign inorganic matter present as an impurity.

The residue obtained generally represents the inorganic salts naturally occurring in the drug and adhering to it. It varies with in definite limits according to the soils. It may also include inorganic matter intentionally added for the purpose of adulteration.

Procedure:

Total Ash Value: Accurately weigh about 3 grams of air dried drug powder in a tarred silica crucible. Note the weight of empty silica crucible and place it along with weighed quantity of drug in to muffle furnace for incineration. Gradually increase the temperature of muffle furnace up to 450-500°C and keep this crucible in muffle furnace until all the carbon burnt off. Cool and weigh you drug after complete incineration, repeat weighing until we get constant value. Then the percentage of total ash is calculated with reference to the air-dried drug.

RESULT: An Ash Value of given crude drug sample was calculated and found to be………..

Calculation:  (Write on Journals blank page).

Weight of empty dish = X

Weight of the drug taken=Y

Weight of the dish + Ash (after complete incineration) = Z

Weight of the ash = (Z-X)g

Y g of the crude drug gives (Z-X) g of the ash

100 g of crude drug gives 100/ Y x (Z-X)

Total ash value of the sample = 100 (Z -X)/ Y %