Analytical chemistry in water quality monitoring during manned space missions

Water quality monitoring during human spaceflights is essential. However, most of the traditional methods require sample collection with a subsequent ground analysis because of the limitations in volume, power, safety and gravity. The space missions are becoming longer-lasting; hence methods suitable for in-flight monitoring are demanded. Since 2009, water quality has been monitored in-flight with colorimetric methods allowing for detection of iodine and ionic silver. Organic compounds in water have been monitored with a second generation total organic carbon analyzer, which provides information on the amount of carbon in water at both the U.S. and Russian segments of the International Space Station since 2008. The disadvantage of this approach is the lack of compound-specific information. The recently developed methods and tools may potentially allow one to obtain in-flight a more detailed information on water quality. Namely, the microanalyzers based on potentiometric measurements were designed for online detection of chloride, potassium, nitrate ions and ammonia. The recent application of the current highly developed air quality monitoring system for water analysis was a logical step because most of the target analytes are the same in air and water. An electro-thermal vaporizer was designed, manufactured and coupled with the air quality control system. This development allowed for liberating the analytes from the aqueous matrix and further compound-specific analysis in the gas phase. (C) 2016 IAA. Published by Elsevier Ltd. All rights reserved.