A novel derivatization procedure, N-acetyl methyl (NACME) esterification, has been developed to improve the accuracy and precision of amino acid delta13C value determination using gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS). Standard mixtures of 15 protein amino acids are converted to NACME and N-acetyl-isopropyl (NAIP) esters; the latter established derivative is employed for comparison purposes. Both procedures yielded baseline-resolved peaks for all 15 amino acids when GC columns coated with polar stationary phases were employed. For NACME esters, the methylation conditions governed reaction yields, with highest yields observe when a 1 h, 70 degrees C methylation procedure (anhydrous MeOH/acetyl chloride, 25:4, v/v) is performed.

Working  direcly with amino ester would be a bit difficult owing to non volatility and chances of decomposition.As suggested by Ravi, you need to convert these amino acids into  n-protected derivatives  One such  as  derivatives are MTBSTFA derivatives  that are  very voltile and can easily be analyzed using capillary column with GC.

You can use HP-5 Column.

https://books.google.co.in/books?id=OyY_6nVJn2gC&pg=PA102&lpg=PA102&dq=aminoacid+methyl+ester+analysis+by+gc&source=bl&ots=6KaNJKnQ1b&sig=CWKkoF0te2UgvFnGdkddzSaM8yQ&hl=en&sa=X&ei=Rzs6VYu2LJP_8QXt34GQDA&ved=0CF4Q6AEwCA#v=onepage&q=aminoacid%20methyl%20ester%20analysis%20by%20gc&f=false