Fatty Acid Methyl Esters

Transesterification

Image . This reaction is known as transesterification. The methyl from the methanol group is added to the carboxylic acid of the fatty acid to create a fatty acid methyl ester.

Sample Preparation

• Combined 200 ul of the sample with 40 ul of anhydrous methanol into a microcentrifuge tube
• Added 4.3 ul of 5 M KOH to the top methanol layer (catalyst)
• Sonicated the tubes in an ultrasonic bath for 30 minutes
• Added 200 ul of 0.1 M acetic acid (neutralize the base catalyst)
• Centrifuged the solution at 6,000 rpm for 5 minutes
• Transferred 40 ul of the top layer to a GC vial and diluted with pentane