Using TMSH to produce FAMEs

Chromatography Forum: GC Archives: Using TMSH to produce FAMEs
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Volker Hahn on Wednesday, January 24, 2001 - 04:58 am:

I would like to get informations about using TMSH in producing FAMEs of sunflower oil to analyze them in a capillary GC.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Wednesday, January 24, 2001 - 07:51 am:

This wasn't what you asked exactly, but here we saponify in NaOH/methanol, acidify and heat 5 minutes with BF3/methanol, cool, add petroleum ether solvent, swirl, add saturated sodium chloride solution, mix, let separate, and inject upper layer into GC. All steps are done in one volumetric flask, taking advantage of the neck.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By H. W. Mueller on Thursday, January 25, 2001 - 07:49 am:

The method presented by "Anonymous" has worked fine in this laboratory as well, even with a slight simplification: we skip the NaOH/MeOH step.
With the normal large excess of MeOH the equilibrium is sufficiently on the side of the methyl ester. This method has been shown by many researchers, partially also in this laboratory, to be very robust.
A recent search about TMSH, including questions to discusion groups (here: "Transesterification with TMSH, Dec. 1; www.stlcdg.org; etc.) did not reveal any thorough studies on the scope of this reaction. No answers have yet been found to the following type of questions: "What effect does splitting rate have on the extend of the reaction (yield)?" . . . . .
Some researchers have found considerable interfering reactions. It appears that the TMSH rea. in the high temperature inlet is only a specialty method.


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