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.