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HFBA derivatization and GC column

Posted: Fri Dec 13, 2013 7:27 pm
by salle
Hello

I Have a little question about HFBA use and its impact on GC column...
I Explain : I want to reduce the time for amphetamine extraction and derivation. So I would like to remove the step of HFBA neutralisation (with pH 7 buffer) so : put directly the HFBA in my solvants, evaporate them and take back my derivatized analytes with ethyl acetate.... do you think it's a good idea or just silly :mrgreen:

thank you for your help

Re: HFBA derivatization and GC column

Posted: Sun Dec 15, 2013 1:52 am
by MSCHemist
I haven't worked with HFBA but have used HFBI. The only thing you really have to do is add some water and the reagent is quenched and stays in the aqueous layer and the nonpolar fraction is transfered and analyzed. Obviously don't use a wax column otherwise HFBA/HFBI should not react with siloxane based columns.

Re: HFBA derivatization and GC column

Posted: Mon Apr 28, 2014 12:14 am
by mrussell
I haven't worked with HFBA but have used HFBI. The only thing you really have to do is add some water and the reagent is quenched and stays in the aqueous layer and the nonpolar fraction is transfered and analyzed. Obviously don't use a wax column otherwise HFBA/HFBI should not react with siloxane based columns.
Doesnt restek make a wax column for use with acids.

Re: HFBA derivatization and GC column

Posted: Wed Apr 30, 2014 2:09 pm
by MSCHemist
everyone has FFA columns now adays Agilent, Restek, Phenomenex. The trouble is you either need an automated headspace analyzer or they are a pain to extract from water.

For amphetamines I know I am like a broken record but I love using the chloroformates for derivitization. They work well on amines especially. You can do the reaction in water extract with chloroform and be done in 20 minutes.