Protocol for Amino Acid Derivatization by MTBSTFA

[avinashsinha]

Hello Everyone,

I want to derivatize amino acids by using N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide (also known as TBDMS-MTFA or MTBSTFA, CAS Number : 77377-52-7). The derivatives of amino acids will subsequently be analyzed on a GCMS.

Can someone please tell me the exact detailed protocol for this type of derivatization and the conditions for the column, GC and MS.

Thanks

[krickos]

Hi

You might find this usefull to start from:
http://www.sigmaaldrich.com/etc/mediali ... /rep28.pdf

check page 17 and onwards

[avinashsinha]

Hi krickos,

Thanks a lot for your post. I did have this document but an earlier release of June, 2007.

But I have a couple of doubts in the Experimental protocol given in the document. I would be very greatful if you could answer them for me. Please see below for the doubts:-

[1] It states in Experiment section, "A 50 μL aliquot of a solution containing a mix of L-amino acids at 91 μg/mL in 0.1 N HCl was dried". Does this mean that it it put in an oven and completely dried and all water removed. If so them at what temperature and for what duration??

[2] There is another statement in the Experiment section "The sample was then neutralized with sodium bicarbonate".
How much Sodium Bicarbonate should be added and what should be the concentration of the Sodium Bicarbonate solution to be used in the step in molar terms of % (w/v).

[3] Is MTBSTFA very hygroscopic? If YES then how should we handle it during the experiment?

[4] Are there any more steps and precautions that I might add to this protocol to get better peak resolution and avoid multiple peaks of the same amino acid?

Eagerly awaiting for you valuable inputs.

Thanks a lot in advance,
Regards
Avinsh Sinha