Paraffin (Finished product) Assay (MOA)
Procedure:
Weigh
and transfer sample equivalent to 2.0 gm, add 10 ml of water, extract with two 40 ml quantities of a mixture of 2 volumes
of ethanol (96%), 3 volumes of petroleum spirit (boiling range, 40° to 60°) and 3
volumes of ether and then with
30 ml of a mixture of equal volumes of petroleum
spirit (boiling range, 40° to
60°) and ether. Wash the
combined extracts with 15 ml of 0.5M sodium
hydroxide and then with 15 ml of water,
evaporate the solvent, add 5 ml of acetone
and evaporate again. Repeat the addition and evaporation of acetone until the residue is free
from water, dry at 105° for 15 minutes and weigh.
Calculation:
Content of Paraffin in gm
Wt. of residue
= ------------------------
x 5
Wt. of sample
% of Paraffin
Paraffin in gm
= -------------------------- x 100
Label claim
