Page 115 - Feed Lab

Suguna Management System Ver 1.0 / SOP / FQL / P2 - 29 Page 1 of 1

29. Estimation of Saponification Value

FAlcoholic KOH: 35-40 gm dissolved in a little
SCOPE
water and diluted to 1 liter with ethanol.
Applicable for determination of all Vegetable oils and
fats. FPhenolphthalein indicator solution - 1.0% in ethyl
alcohol.
OBJECTIVE
FThe saponification value is the amount of PROCEDURE
alkali necessary to saponify a definite quantity of the FTake 4.0 to 5.0 gm oil n flat bottom flask 250 ml &
sample. It is expressed as the number of milligrams of add 50 ml Alcoholic KOH.
potassium hydroxide (KOH) required saponifying 1
gram of the sample. FConnect the air condenser and boil gently on
a soxhlet heater until the sample is completely
saponified (approx 1 hr) .
APPARATUS
FAir condenser FThen cool and wash the condenser with a little
distilled water, add 1 ml of phenolphthalein
FSoxhlet Heater
indicator & titrate with N/2 Hcl solution till the pink
FFlat bottom flask color just disappears.
FNote the reading. For blank run, use same
REAGENTS
procedure without sample.
FHydrochloric acid 0.5 N accurately standardized.

CALCULATIONS
(B-S) x (N)
Saponification value = ----------------------- x 56.1
W

Where: B = ml 0.5 N HCl required to titrate blank
S = ml 0.5 N HCl required to titrate sample
N = normality of HCl solution
W = weight of sample in grams REFERENCE : AOCS Cd3 - 25

Prepared by : Approved by :
103 Director - Technical