STABLE-ISOTOPE RATIO ANALYSIS OF AMINO-ACIDS - THE USE OF N(O)-ETHOXYCARBONYL ETHYL-ESTER DERIVATIVES AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A sensitive methodology suitable for the rapid determination of specif ic enrichment of stable isotopically labelled tracer amino acids in bl ood plasma and protein hydrolysates using their N(O)-ethoxycarbonyl et hyl ester derivatives and gas chromatography/mass spectrometry (GC/MS) has been developed, Complete derivatizatian, separation and determina tion of sample tracer enrichments can be satisfactorily finished withi n less than 10 min, The precision and accuracy of the method, the simp le and rapid sample preparation for analysis by GC/MS and the possibil ity of using the electron impact ionization mode render this method pa rticularly appropriate for the evaluation of amino acid or protein met abolism in vivo in clinical studies dealing with large numbers of samp les daily.