Specific methylation of fatty acids

[ssankella]

Hello everyone
I am trying to methylate/esterify the fatty acids present in muscle phospholipids.
1st I digest the phospholipid to release the fatty acid in C-2 position and then esterify it.
I follow the method from "Direct esterification" published by Lepage and Roy, which includes addition of methanol:benzene 4:1 and incubation for 1 hr at 100C. Then neutralized with K2CO3 and the top benzene layer is used for GC analysis.


The problem am facing is..........this method esterifies both the fatty acids present in C-1 and C-2 position of Phospholipids whereas my objective is to esterify only the enzyme digested fatty acid.

Can someone suggest me a method.
Thanks

Sankella

[HW Mueller]

Diazomethane should do the trick.
By the way where did you see this use of benzene, many labs have banned benzene from their labs in such unnecessary applications.

[skunked_once]

Here is a web site with lots of good information on derivatization and GC analysis of fatty acids.

http://lipidlibrary.aocs.org/GC_lipid/gc_lip.html

[ssankella]

Thanks guys!