2.2.2 Saponification value
The AOCS official method Cd 3-25 was followed for the determination of
the saponification value of the FAD sample. About 5g of PFAD was weighed
into a round bottom flask and refluxed for 60mins in the presence of
50ml of 95% ethanoic potassium hydroxide. In the end, titration was
carried out against standard solution of 0.5N hydrochloric acid using
phenolphthalein as indicator.
\begin{equation}
Saponification\ value=\ \frac{\left(S-B\right)\ .\ N\ .\ 56.10}{W}\nonumber \\
\end{equation}where S is the 0.5 N HCl solution for titration of the sample (ml), B is
the 0.5 N HCl solution required for titration of the blank (ml), N is
the normality of HCl solution, and W is the weight of sample (g). The
PFAD sample was saponified with excess of alcoholic potassium hydroxide.
Titration with HCL indirectly delivers the amount of KOH consumed.