Thorleaf Research, Inc. has demonstrated feasibility in Phase I and now proposes a Phase II effort to develop a miniaturized high flow, low dead-volume preconcentrator for monitoring trace levels of contaminants in liquid water under microgravity conditions. Our innovative design for the preconcentrator combines high water sampling flow rates with low dead volume, thus enhancing preconcentration. This is designed to meet monitoring needs for NASA's Spacecraft Water Exposure Guidelines (SWEGs) and addresses a key technology gap for long-duration human spaceflight, since standard techniques will not function without gravitation to stabilize phase boundaries. Human exploration of the solar system will depend on such technology, since water must be recycled and the option of returning grab samples to Earth for analysis from beyond low-Earth orbits does not exist. During Phase II, we plan to incorporate this technology into a miniaturized water preconcentrator module. Based on our Phase I results we project that it will be possible to develop this module with a mass of about 0.5 kg and average power consumption of <1 watt.