Method
for the estimation of Glycyrrihizin
content
Reagent
Required:
Methanol L.R. Grade, Sulphuric acid, Ammonia
solution.
Glass
wares and Apparatus Required:
250mL Conical flask, Gooch crucible, 50mL
Stoppered cylinder and Evaporating dish.
Procedure:
Weigh accurately about 2.5gm of dry extract
powder in a 250mL conical flask, Add 15mL of hot water, cover with watch glass
and stand the flask on water bath until the juice has dissolved, shaking
frequently. Add 25mL of 80% alcohol. Shake well and then add 50mL of 95%
alcohol. Allow to settle and filter through a tared gooch crucible containing a
filter paper and washing with 80% alcohol until the washings are colourless.
Transfer the filter and washing to a dish and evaporate the alcohol. Evaporate
further to syrup and transfer to a 50mL stopper cylinder. Washing with water
upto 30mL. Add 3mL of 10% sulphuric acid and slowly with constant shaking.
Allow to stand overnight at a temperature of about 150C. And then
decent the supernatant liquid through a filter. Wash the precipitate two or
three times with ice cold water and pass the washing through the filter.
Dissolve the residue in the cylinder in a little dilute alcohol (90%), adding
two or three drops of ammonia to
neutralize the acid. Evaporate to dryness in a tared dish and weigh.
Calculation:
Percentage of Glycyrrihizin content is calculated as:
(A – B) X 100
W
A = Weight of residue and dish
B = Weight of empty dish
W = Weight of material taken
No comments:
Post a Comment