Fatty acid anhydride

[michelle.zhang]

Dear Memebers,
My cowoker synthesized anhydride from a mixed fatty acid(from C8-C16) as some kind of intermediate reagent. Now she need to know what is the C-chain distribution in mix anhydride.
It is trouble that anhydride will decompose to acid form during runing in the GC column, we confirmed by Mass.
Obviousely, HPLC does not work for this kind of analysis.
I will appreciate for any comment, suggestion for method we can analyze the c-chain distribution of anhydride.
Michelle

[Mark]

michelle,

Why not let it react to give the acids and then analyze the acids. This would give the composition of the original anhydride.

Regards,
Mark

[michelle.zhang]

Mark,
My colleague prefers to know if there is competance among different c-chain fatty acids. For example, C-8 may be easy dehydrate with C18 or not.
However, it seems hard to identify til now.
Michelle

[oscarBAL]

Hello, I don't know if this could work, but if you inject your sample with a rate temperature on the injection port, that could avoid the anhidride hydrolysis, but finally yuo will have to increase the temperature so much for eluate the havy anhidrides, is just and idea, and think that the usual column for fatty acid have a temperature limit.