Development of Streamlined Methods for Integration into Multiplexed Colorimetric Solid Phase Extraction (MC-SPE) Analysis of Spacecraft Water

Abstract

The need to preserve crew health during space missions, combined with the level of demand on both crew time and cargo space, dictates the development of fast, facile methods capable of monitoring trace quantities of several analytes in spacecraft water. This presentation describes our efforts to address this need by using Multiplexed Colorimetric Solid Phase Extraction (MC-SPE). MC-SPE is a sorption-spectrophotometric platform based upon the extraction of analytes onto membranes impregnated with selective colorimetric agents. Quantification is accomplished using Kubelka-Munk values calculated from the diffuse reflectance spectrum of the complex on the surface of the membrane and calibration curves. In traditional C-SPE, concentration factors of up to 1000 can be realized for a single analysis, yielding low detection limits (ppb - ppm range) with a total analysis time of 75-90 s. Herein, we describe the performance and continued refinement of the MC-SPE platform. MC-SPE involves the parallel sample preparation and extraction of analytes on an addressed membrane, followed by the serial readout of each address. This strategy is designed to optimize the detection of high priority analytes in spacecraft water, while maintaining the low detection limits of C-SPE and reducing the overall analysis time. The status of our development and testing of this strategy using aqueous standards will be discussed.