Identification of amino acids by capillary gas chromatography. Applicationto Martian samples

In the search for extant or extinct life on Mars, determination of amino ac ids and their chirality is of prime interest. For in-situ measurement the m ost suitable analytical method is currently gas chromatography combined wit h mass spectrometry (GC-MS). Derivatization, which is needed for analysis o f amino acids by GC, has never been performed in space. We present here a o ne step-silylation method and compare the separation and the sensitivity wi th those of a double-step derivatization technique (N-pentafluoropropanoyli sopropyl ester derivatives) performed in laboratories. The chiral separatio n of the fluorinated amino acids on two chiral columns shows the complement arity of the columns for resolution of the different enantiomers of alpha - hydrogenated and alpha -dialkyl amino acids.