Quantitative enantioseparation of amino acids by comprehensive two-dimensional gas chromatography applied to non-terrestrial samples.

This work presents an improved analytical procedure for the resolution and quantification of amino acid enantiomers by multidimensional gas chromatography. The procedure contains a derivatization step, by which amino acids were transformed into N(O,S)-ethoxycarbonylheptafluorobutyl esters. It was optimized for the resolution of non-proteinogenic amino acids in the matrix of complex non-terrestrial samples. The procedure has proven to be highly sensitive and shows a wide linearity range with 0.005-3 pmol detection limits for quantitative determinations. The developed procedure was tested on a sample of the Murchison meteorite, for which obtained chromatograms show excellent peak resolution, minimal co-elution and peak overlap. We conclude that comprehensive two dimensional chromatography, in combination with the optimized derivatization method is a highly suitable technique for the analysis of samples with very limited quantities and containing potentially prebiotic molecules, such as interstellar ice analogs and meteorites.