FAME by GC

[Jen]

I am working on red blood cell fatty acid analysis by GC
I am using 10% BF3 in MeOH to convert the fatty acid to FAME.
Heat the red blood cell and BF3-MEOH at 100°C for 60 minutes. Cooling, Add 1ml of H2O and 1ml of Hexane.

We add the hexane to extract the FAME into hexane for GC analysis.
But I don’t understand why we need to add the 1ml of water.
Will the water drive the esterification reaction to the left side?
I am new to FAMEs, thank you for your support

[Consumer Products Guy]

The water is not part of the reaction; actually when methanol is esterified with a fatty acid, one molecule of water is created. The addition of water is for solubilization of any polar components; the immiscible hexane layer will contain the FAME. Of course, our fatty acids here are from consumer products, not blood. We also add some NaCl to enhance the separation of the hexane from the aqueous portion.

The BF3 is a Lewis acid, catalyst for the reaction; we've used both BF3 or dilute H2SO4 as the acid for this.

[skunked_once]

This is a useful web site for lipid analysis.

http://lipidlibrary.aocs.org/GC_lipid/0 ... /index.htm

Enjoy learning and post more questions if they arise. We're here to help