Identification of amino acids by capillary gas chromatography. Application to martian samples

In the search for extant or extinct life on Mars, determination of amino acids and their chirality is of prime interest. For in-situ measurement the most suitable analytical method is currently gas chromatography combined with mass spectrometry (GC-MS). Derivatization, which is needed for analysis of amino acids by GC, has never been performed in space. We present here a one step-silylation method and compare the separation and the sensitivity with those of a double-step derivatization technique (N-pentafluoropropanoylisopropyl ester derivatives) performed in laboratories. The chiral separation of the fluorinated amino acids on two chiral columns shows the complementarity of the columns for resolution of the different enantiomers of α-hydrogenated and α-dialkyl amino acids.