The State-of-the-art in Capillary Electrophoresis and Microchip Electrophoresis Instrumentation for Ocean Worlds Missions Seeking Signs of Life

Introduction: A reasonable assumption in the search for life on ocean worlds is that the limit of detection required of analytical instrumentation for dissolved organics is on the order of parts-per-billion, which is similar to the concentration of organics in extreme environments such as subglacial Lake Vostok in Antarctica [1]. This limit of detection requirement is challenging to meet using traditional, high-TRL instrumentation such as gas-chromatography mass spectrometry (GC-MS), which has been demonstrated to be capable of detecting organics such as amino acids and carboxylic acids at the parts-per-million level [2]. In order to increase the sensitivity of this gas phase technique to nonvolatile organics, one needs to develop methods and instrumentation for liquid-handling pre-processing steps prior to gas-phase separations. These steps include removal of interfering water or solids from samples, and reaction of the sample with molecules that create new molecular adducts having a significant vapor pressure, that can then be vaporized and analyzed by GC-MS. This was the general approach taken by the SAM instrument on Mars, although in that case no sample processing was performed [2].