Dear Gerd Gleixner and other interested persons for AA analytical techniques,

last week you wrote about derivatisation techniques of AA for the stable
isotopes measurement of 15N and 13C. We have been working on this field for
some years (especially 15N in natural variations). We have tested and
compared different derivatisation methods. By our experience the best
suitable technique for the determination of aa and their amides is the
t.-butylmethylsilylation. But you cannot measure Arg very well with this
derivatisation. I would use the derivatisation technique esterification
with triflouroacetalation for the determination of Arg and Gly. For
furthermore information contact me directly, please.

Matthias Gehre


>Dear Wolfgang, are you shure that these methods are suitable to measure
arginine. This
>is one of the most critical AA in GC-C-IRMS. Other critical ones are . Has
anyone a satisfying derivatisation method to
>get them all. For 15N and 13C.
>Thanks gerd gleixner
>

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Matthias Gehre
Centre for Environmental Research Leipzig-Halle
Laboratory of Stable Isotopes

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Germany                         Germany

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