Dear Ahmed

The preparation is not as simple as just hydrolysing the proteins and the analysing it with LC-MS. You will also need to derivatise the amino acids in order to improve bot the the separation on a column and/or to aid in visualisation of the amino acid. Have a look at the following book:

http://www.scribd.com/doc/23505508/Amino-Acid-Analysis-Protocols

Two derivatization methods from Waters, Pico-Tag method and the Accu-Tag method, are generally used in the LC-MS analysis of amino acids. Have a look at these links to some of the application notes:

http://www.waters.com/webassets/cms/library/docs/720001946en.pdf

http://www.chromatographyonline.com/lcgc/data/articlestandard//lcgcasia/402006/376668/article.pdf

Also note the amino acid analysis is quite a specialised analytical technique demanding high accuracy and repeatability in sample preparation and analyses, as well as quite expensive derivatisation kits/reagents, standards and columns. If there is any possibility that you can out-source the amino acid analysis of your samples to a facility dedicated to amino acid analysis, I would advise that you do just that. I speak from decades of experience in doing amino acid analyses.

Hope it helps.

Regards

Marina

I also have similar question, unfortunately the above links are not working. 

Dear Suluh

These links are quite old so no wonder the lapsed. Try the following ones:

http://www.waters.com/waters/library.htm?cid=511436&lid=1524232&locale=en_ZA (On page application note that gives a few good references)

http://www.ncbi.nlm.nih.gov/pubmed/19937719

http://www.springer.com/us/book/9781617794445

There are many other online sources that you can find with a simple Google or PubMed search. Hope it helps.

Regards

Marina