Life Marker Chip Sample Processing Post PCR#2 (Q3 2009 to Q3 2010)

从火星样品中提取有机分子并随后将其运送到能够表征其化学性质的仪器是一项重大的分析挑战。由于目标分子的各种化学性质，困难出现了。生物分子主要是极性的，并且容易溶解于水溶液中，而化石有机分子是非极性的，并且溶解于有机溶剂中;非生物分子可以包含两种类型。火星的溶剂必须能够科普所有类型的有机分子。我们目前的方法使用表面活性剂/水/甲醇溶液。此外，有机分子可以存在于许多岩性中，每个岩性可以选择性地保留某些分析物。这些基质效应是有效提取程序的潜在障碍。宿主岩性也可能产生溶剂化学的变化，这在运输期间对其提取效率或特性具有有害影响。

The extraction of organic molecules from samples on Mars and their subsequent delivery to an instrument capable of characterizing their chemistry represents a substantial analytical challenge. Difficulties arise because of the various chemical properties of the target molecules. Biological molecules are predominantly polar and dissolve readily in aqueous solutions whereas fossil organic molecules are non polar and dissolve in organic solvents; abiotic molecules can contain both types. A solvent for Mars must be able to cope with all types of organic molecule. Our current method uses a surfactant/water/methanol solution. Moreover, the organic molecules may reside in a number of lithologies each of which can selectively retain certain analytes. These matrix effects represent potential barriers for effective extraction procedures. The host lithologies may also produce changes in solvent chemistry which has a deleterious effect on its extraction efficiency or characteristics during transport.