Selection and analytical performances of the Dragonfly Mass Spectrometer (DraMS) chromatographic columns in search for organic molecules of biological interest on Titan.
Résumé
Titan is a key planetary body for astrobiology, with the presence of a subsurface ocean and a dense atmosphere, in which complex chemistry is known to occur. Dragonfly, a rotorcraft, will land at Titan's surface for an exhaustive geophysical and chemical investigation of the moon. Dragonfly is composed of four instruments amongst which the Dragonfly mass-spectrometer (DraMS). One of DraMS subsystem, the Gaz Chromatograph-Mass Spectrometer (GC-MS), is dedicated to the detection of organic molecules that could be involved in the development of a prebiotic chemistry or even representatives of traces of past or present life. DraMS-GC should be optimized to detect and identify relevant organic compounds to meet this objective. This work focused on the experimental methods deployed to select the general column for DraMS-GC, to assess its performances and also assess the performances of the other, chiral, column for enantiomeric separation. Four stationary phases have been tested for the selection, using chemical standards, representative mixtures and analog samples. The results show that the RTX-5 stationary phase is the best compromise in terms of efficiency, robustness and retention times of the molecules. Moreover, the chiral column has the ability to resolve the enantiomeric separation of most of the compounds tested.