干旱区生态环境知识资源中心(Arid): A Subcritical Water Extractor Prototype for Potential Astrobiology Spaceflight Missions

Arid

DOI	10.1029/2019EA000803
	A Subcritical Water Extractor Prototype for Potential Astrobiology Spaceflight Missions
	Kehl, F.1; Kovarik, N. A.1; Creamer, J. S.1; da Costa, E. T.1,2; Willis, P. A.1
通讯作者	Willis, P. A.
来源期刊	EARTH AND SPACE SCIENCE
EISSN	2333-5084
出版年	2019
卷号	6 期号:12 页码:2443-2460
英文摘要	A top-level NASA exploration goal is the search for signs of life beyond Earth. Molecular biosignatures can be sought via in situ organic chemical analyses of samples collected from planetary bodies. Current spaceflight-ready technologies lack the required sensitivity to perform these analyses on key polar organic species primarily due to the low efficiency of transferring these molecules from natural samples into chemical instrumentation. One promising approach to improve the liberation of these molecules from sample matrices prior to analysis is through the use of liquid extraction, in which organic molecules are dissolved in heated, pressurized water. This process has never been performed on a spaceflight mission. As part of instrument maturation efforts, we describe the development of the first spaceflight prototype of a fully automated subcritical water extractor designed to provide this essential functionality on a potential future planetary mission. The prototype extractor was mounted on a Mars test rover platform and successfully operated remotely in the Atacama Desert, Chile. Samples acquired by the rover's drill and sample acquisition/delivery system were remotely transferred to the extractor inlet funnel, and all subsequent extractor operations were performed automatically. To validate the instrument and demonstrate its suitability as a front-end unit for an organic analyzer, we tested low-bioload Atacama Desert soil extracts for amino acid content using capillary electrophoresis coupled to laser-induced fluorescence. We show that hot extraction under subcritical conditions is required to liberate amino acids from the sample, as no amino acids were found in the extract produced at room temperature. Plain Language Summary The search for signs of life beyond Earth is one of NASA's highest priorities. One powerful way to look for extraterrestrial life is to perform chemical analyses on planetary samples in order to characterize any organic molecules present. Past and current spaceflight instruments analyze various components in gases collected or gases produced from solid samples; however, the instruments either lack the sensitivity to detect organic molecules or the instruments destroy many of the organic molecules during the preparation required to perform a gas-phase-based measurement. This work presents an automated pressurized hot water extractor that can be used to release organic molecules from a solid sample. Pressurized hot water is a powerful and easy-to-handle solvent for a wide range of different compounds. The extractor acts as a front-end instrument and prepares the sample for highly sensitive, liquid-based analysis. This automated and remotely controlled prototype has been successfully tested on a simulated Mars rover mission in the Atacama Desert in Chile. Extracts of the Atacama soil samples were then analyzed by capillary electrophoresis coupled to laser-induced fluorescence to determine the extracts' amino acid content, as amino acids are an auspicious class of molecules in the search for life.
英文关键词	astrobiology Atacama Desert capillary electrophoresis life detection subcritical water extraction
类型	Article
语种	英语
国家	USA ; Brazil
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000503341800001
WOS关键词	AMINO-ACIDS ; ORGANIC-MATTER ; CAPILLARY-ELECTROPHORESIS ; MARS ; SEARCH ; TEMPERATURES ; LIFE ; UREY
WOS类目	Astronomy & Astrophysics ; Geosciences, Multidisciplinary
WOS研究方向	Astronomy & Astrophysics ; Geology
EI主题词	2019-12-19
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/311853
作者单位	1.CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA; 2.Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, Sao Paulo, SP, Brazil
推荐引用方式 GB/T 7714	Kehl, F.,Kovarik, N. A.,Creamer, J. S.,et al. A Subcritical Water Extractor Prototype for Potential Astrobiology Spaceflight Missions[J],2019,6(12):2443-2460.
APA	Kehl, F.,Kovarik, N. A.,Creamer, J. S.,da Costa, E. T.,&Willis, P. A..(2019).A Subcritical Water Extractor Prototype for Potential Astrobiology Spaceflight Missions.EARTH AND SPACE SCIENCE,6(12),2443-2460.
MLA	Kehl, F.,et al."A Subcritical Water Extractor Prototype for Potential Astrobiology Spaceflight Missions".EARTH AND SPACE SCIENCE 6.12(2019):2443-2460.