2.8. Extractions
For extractions, 5.0 mLof 35% ChCl DES prepared with waste glycerol
froman acid-catalyzed biodiesel synthesis was added to a 25mL round bottom
flask containing 5.0 mL biodiesel. Various volume ratios of
methanol were added, ranging from 1:20 to 1:5 (methanol:biodiesel).
The solutions were magnetically stirred at room temperature. Every
hour, stirring was turned off and the two layers were allowed to settle
for 5min. An aliquot of the top biodiesel layerwas removed and subjected
to 1H NMR analysis in CDCl3 to monitor the amount of methanol remaining
in the biodiesel.