A new extraction technique for in situ analyses of amino and carboxylic acids on Mars by gas chromatography mass spectrometry

In order to target key organic compounds in the Martian regolith using gas chromatography mass spectrometry (GC-MS), we have developed a new extraction procedure coupled with chemical derivatization. This new technique was tested on a Mars analog soil sample collected from the Atacama Desert in Chile. We found that amino and carboxylic acids can be extracted from the Atacama soil in a 1:1 mixture of isopropanol and water after ultrasonic treatment for 30 min. The extracted organic compounds were then derivatized in a single-step reaction using N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) as the silylating agent in order to transform these compounds into volatile species that can then be detected by GC-MS. We are currently developing a miniaturized reaction cell suited for spaceflight, where both organic extraction and chemical derivatization processes can take place in a single step. (c) 2006 Elsevier Ltd. All rights reserved.