Thorleaf Research, Inc. proposes to develop a miniaturized high flow, low dead-volume pre-concentrator for monitoring trace levels of contaminants in water under microgravity conditions. Our innovative design for the pre-concentrator assembly combines high water sampling flow rates with low dead volume in the device, enhancing pre-concentration while avoiding cavitation effects. This will help meet monitoring needs for NASA's Spacecraft Water Exposure Guidelines (SWEGs). Although miniaturized mass spectrometers and other detectors are under development by NASA, the potential of such instrumentation to meet NASA needs will not be realized without complementary developments in the technology for collecting and preparing samples for in situ measurements. Based on our analysis, we project that it will be possible to develop a miniaturized water pre-concentrator module with a mass on the order of 0.5 kg and an average power consumption of <1 watt, depending on the configuration selected. Our goal in the proposed SBIR Phase I effort is to demonstrate feasibility for such a system and to develop a detailed design for fabricating and demonstrating prototypes in Phase II.