3] Gas-liquid chromatography (GLC) of amino acid derivatives

Abstract

This chapter presents gas-liquid chromatography (GLC) methods for the separation of D and L amino acids. An interesting application is the analysis of amino acids in the Murchison meteorite. The D and T, enantiomers of certain amino acids are determined as the N-TFA-D-2-butyl esters. Optically active stationary phases are used to separate stereoisomers of amino acids. In considering the relative merits of the GLC method to established ion-exchange procedures, an important factor is the sample preparation prior to derivatization. Most biological samples require a separation of amino acids from interfering substances on a cation-exchange resin. Some samples, such as urine, require a clean-up on both cation and anion exchange resins. The samples could be analyzed directly by the established ion-exchange methods and in less time than it takes to accomplish the clean-up on both cation and anion exchange resins. Clean-up of hydrolyzates of most pure proteins and peptides is not necessary, and it seems that the GLC method has its greatest applicability in this area of analysis.