ALBERT

Description: This paper continues the annual tradition of summarizing at this conference the results of chemical analyses performed on archival potable water samples returned from the International Space Station (ISS). 2016 represented a banner year for life on board the ISS, including the successful conclusion for two crew members of a record one-year mission. Water reclaimed from urine and/or humidity condensate remained the primary source of potable water for the crew members of ISS Expeditions 46-50. The year 2016 was also marked by the end of a long-standing tradition of U.S. sampling and monitoring of Russian Segment potable water sources. Two water samples taken during Expedition 46 in February 2016 and returned on Soyuz 44, represented the final Russian Segment samples to be collected and analyzed by the U.S. side. Although anticipated for 2016, a rise in the total organic carbon (TOC) concentration of the product water from the U.S. water processor assembly due to breakthrough of organic contaminants from the system did not materialize, as evidenced by the onboard TOC analyzer and archive sample results.

Description: In September of 2010, analysis of ISS potable water samples was undertaken to determine the contaminant responsible for a rise in total organic carbon (TOC). As analysis of the routine target list of organic compounds did not reveal the contaminant, efforts to look for unknown compounds was initiated, resulting in an unknown peak being discovered in the gas chromatography/mass spectrometry (GC/MS) analysis for glycols. A mass spectrum of the contaminant was then generated by concentrating one of the samples by evaporation and analyzing by GC/MS in full-scan mode. Although a computer match of the compound s identity could not be obtained with the instrument s database, a search with a more up to date mass spectral library yielded a good match with dimethylsilanediol (DMSD). Inductively Coupled Plasma/Mass Spectrometry (ICP/MS) analyses showed abnormally high silicon levels in the samples, confirming that the unknown contained silicon. DMSD was then synthesized to confirm the identification and provide a standard to develop a calibration curve. Further confirmation was provided by external Direct Analysis in Real Time (DART) GC/MS analysis. A preliminary GC/MS method was then developed and archived samples from various locations on ISS were analyzed to determine the extent of the contamination and provide data for troubleshooting. This paper describes these events in more detail as well as problems encountered in routine GC/MS analyses and the subsequent development of high performance liquid chromatography and LC/MS/MS methods for quantitation of DMSD.

Description: Scientists and engineers from the Wyle Integrated Science and Engineering Group are working with researchers at the University of Utah and Iowa State University to develop and certify an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE). The kit will be launched as a Station Development Test Objective (SDTO) experiment and evaluated on the International Space Station (ISS) to determine the acceptability of CSPE technology for routine inflight water quality monitoring. Iodine and silver, the biocides used in the US and Russian on-orbit water systems, will serve as test analytes for the technology evaluation. This manuscript provides an overview of the CSPE SDTO experiment and details the development and certification of the experimental water quality monitoring kit. Initial results from reagent and standard solution stability testing and environmental testing performed on the kit hardware are also reported.

Description: In September 2010, analysis of ISS potable water samples was undertaken to determine the contaminant(s) responsible for a rise of total organic carbon (TOC) in the Water Processor Assembly (WPA) product water. As analysis of the routine target list of organic compounds did not reveal the contaminant, efforts to look for unknown compounds were initiated, resulting in discovery of an unknown peak in the gas chromatography/mass spectrometry (GC/MS) analysis for glycols. A mass spectrum of the contaminant was then generated by concentrating one of the samples and analyzing it by GC/MS in full-scan mode. Although a computer match of the compound identity could not be obtained with the instrument database, a search with a more up-to-date mass spectral library yielded a good match with dimethylsilanediol (DMSD). Inductively coupled plasma/mass spectrometry (ICP/MS) analyses showed abnormally high silicon levels in the samples, confirming that the unknown compound(s) contained silicon. DMSD was then synthesized to confirm the identification and provide a standard to develop a calibration curve. Further confirmation was provided by external direct analysis in real time time of flight (DART TOF) mass spectrometry. To routinely test for DMSD in the future, a quantitative method was needed. A preliminary GC/MS method was developed and archived samples from various locations on ISS were analyzed to determine the extent of the contamination and provide data for troubleshooting. This paper describes these events in more detail as well as problems encountered in routine GC/MS analyses and the subsequent development of high performance liquid chromatography and LC/MS/MS methods for measuring DMSD.

Description: Two simulated spacecraft water systems are being used to evaluate the effectiveness of iodine for controlling microbial contamination within such systems. An iodine concentration of about 2.0 mg/L is maintained in one system by passing ultrapure water through an iodinated ion exchange resin. Stainless steel coupons with electropolished and mechanically-polished sides are being used to monitor biofilm formation. Results after three years of operation show a single episode of significant bacterial growth in the iodinated system when the iodine level dropped to 1.9 mg/L. This growth was apparently controlled by replacing the iodinated ion exchange resin, thereby increasing the iodine level. The second batch of resin has remained effective in controlling microbial growth down to an iodine level of 1.0 mg/L. SEM indicates that the iodine has impeded but may have not completely eliminated the formation of biofilm. Metals analyses reveal some corrosion in the iodinated system after 3 years of continuous exposure. Significant microbial contamination has been present continuously in a parallel noniodinated system since the third week of operation.

Description: Mass Spectrometry/Mass Spectrometry (MS/MS) is a powerful technique for identifying unknown organic compounds. For non-volatile or thermally unstable unknowns dissolved in liquids, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) is often the variety of MS/MS used for the identification. One type of LC/MS/MS that is rapidly becoming popular is time-of-flight (TOF) mass spectrometry. This technique is now in use at the Johnson Space Center for identification of unknown nonvolatile organics in water samples from the space program. An example of the successful identification of one unknown is reviewed in detail in this paper. The advantages of time-of-flight instrumentation are demonstrated through this example as well as the strategy employed in using time-of-flight data to identify unknowns.

Description: The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.

Description: A liquid-chromatography technique has been developed for use in the quantitative analysis of urea (and of other nonvolatile organic compounds typically found with urea) dissolved in water. The technique involves the use of a column that contains an ion-exclusion resin; heretofore, this column has been sold for use in analyzing monosaccharides and food softeners, but not for analyzing water supplies. The prior technique commonly used to analyze water for urea content has been one of high-performance liquid chromatography (HPLC), with reliance on hydrophobic interactions between analytes in a water sample and long-chain alkyl groups bonded to an HPLC column. The prior technique has proven inadequate because of a strong tendency toward co-elution of urea with other compounds. Co-elution often causes the urea and other compounds to be crowded into a narrow region of the chromatogram (see left part of figure), thereby giving rise to low chromatographic resolution and misidentification of compounds. It is possible to quantitate urea or another analyte via ultraviolet- and visible-light absorbance measurements, but in order to perform such measurements, it is necessary to dilute the sample, causing a significant loss of sensitivity. The ion-exclusion resin used in the improved technique is sulfonated polystyrene in the calcium form. Whereas the alkyl-chain column used in the prior technique separates compounds on the basis of polarity only, the ion-exclusion-resin column used in the improved technique separates compounds on the basis of both molecular size and electric charge. As a result, the degree of separation is increased: instead of being crowded together into a single chromatographic peak only about 1 to 2 minutes wide as in the prior technique, the chromatographic peaks of different compounds are now separated from each other and spread out over a range about 33 minutes wide (see right part of figure), and the urea peak can readily be distinguished from the other peaks. Although the analysis takes more time in the improved technique, this disadvantage is offset by two important advantages: Sensitivity is increased. The minimum concentration of urea that can be measured is reduced (to between 1/5 and 1/3 of that of the prior technique) because it is not necessary to dilute the sample. The separation of peaks facilitates the identification and quantitation of the various compounds. The resolution of the compounds other than urea makes it possible to identify those compounds by use of mass spectrometry.

Description: No abstract available

Description: This paper continues the annual tradition, at this conference, of summarizing the results of chemical analyses performed on archival potable water samples returned from the International Space Station (ISS). 2016 represented a banner year for life aboard the ISS, including the successful conclusion for 2 crewmembers of a record 1-year mission. Water reclaimed from urine and/or humidity condensate remained the primary source of potable water for the crewmembers of ISS Expeditions 46-50. The year was also marked by the end of a long-standing tradition of U.S. sampling and monitoring of Russian Segment potable water sources. Two water samples, taken during Expedition 46 and returned on Soyuz 44 in March 2016, represented the final Russian Segment samples to be collected and analyzed by the U.S. side. Although anticipated for 2016, a rise in the total organic carbon (TOC) concentration of the product water from the U.S. water processor assembly due to breakthrough of organic contaminants from the system did not materialize, as evidenced by the onboard TOC analyzer and archival sample results.