International audienceOne of the priorities of the Mars Science Laboratory mission is the search for a past or present prebiotic chemistry. Among the possible indicators of such a chemistry, the organic molecules are key entities linked to the emergence and the development of life, as we know it on Earth. However, only rare evidences of the presence of such molecules (chlo-robenzene and other chlorinated hydrocarbons), in the Mars sedimentary rocks [1] and regolith [2] , were recently found at a very low concentration (150-300 ppbw in the Cumberland mudstone). Thus, one of the most pressing questions is to follow the search and identification of molecules currently present at Mars and their concentration. Onboard the NASA Curiosity currentl...