Hi, everybody,

My name is yaowi xiao and I am a graduate student in the Chemistry
Department at Syracuse Uinversity.  I am writing you as I have a protein
to be analyzed using GC-IRMS (I guess).  I  would like to know whether
the following measurement can be carried out in your lab or you have any
idea about where this measurement can be carried out.

Instead of trying to perform mass spec directly on the entire protein, or
even on peptide fragments, I only wish to perform a mass analysis on the
20 individual amino acid types within the protein.  That is, I would like
to have the protein hydrolyzed to individual amino acids, then separate
these 20 amino acids with chromatography, and determine, for each of
them, the amount of 15N present. We are starting out with a protein that
was grown on a media with arginines doubly-labelled with 15N, to a level
of >95%, and natural-abundance nitrogen isotopes on all the other amino
acids.  We would like to determine, to the nearest 1%, the 15N content of
each amino acid.

I look forward to your kind reply.  Regards and best wishes,
yaowu