2.2. Transesterification of waste lipid using potassium hydroxide
To a mixture of waste lipid (1 g) and KOH (0.05 g, 5 wt.%), different amounts of methanol (147 lL and 457 lL) were added. Reactions were carried out at 1:3 and 1:10 M ratio of lipid to
methanol and the reaction temperatures were 40 _C and 60 _C. After 2 h of reaction the obtained mixture was neutralized with dilute sulfuric acid and extracted using ethyl acetate. The resulting mixture was filtered through anhydrous sodium sulfate to remove the water phase. The obtained organic phase was dried under vacuum at 60 _C. Subsequently, the obtained sample was used for 1H NMR analysis.
lipid to FAME produced in each reaction was calculated using 1HNMR (Knothe, 2000; Karmee and Chadha, 2005). A Bruker 400 MHz instrument was used for recording of 1H NMR spectra.
The reaction was monitored qualitatively by thin layer chromatography (TLC). The TLC plates were purchased from Macherey–Nagel, Dren, Germany. All reactions were performed in 50 mL round bottomed flasks. Each reaction was carried out in duplicate and the results presented here were averaged.