The Spacecraft Atmosphere Monitor (SAM.) is a scientific payload, which includes a Paul quadrupole ion trap (QIT) mass spectrometer and has been continuously operated onboard the International Space Station (ISS) between August 2019 and July 2021. S.A.M. measures the chemical composition of ISS cabin air and reports on major constituents (N-2, O-2, Ar, CO2, and CH4) once every 2 s. Each second, S.A.M. measures one hundred individual mass spectra stored in 4800 ins-long channels. This report presents the autonomous onboard data analysis software that calibrates the mass spectrum, removes the residual gas background signal, identifies species of interest, and reports relevant abundances. In addition, we describe a ground-based analysis of downloaded S.A.M.'s data to extract the H, C, N, O, and Ar isotope ratios. We also describe experiments, requested by the ISS Vehicle office, to ascertain if benzene was present in the ISS cabin air (it was not). We demonstrate that S.A.M. instrument measures isotope ratios with precision and accuracy comparable to the state-of-the-art laboratory-size magnetic sector mass spectrometers. (C) 2022 Elsevier B.V. All rights reserved.

Marianne Gonzalez, National Aeronautics and Space Administration (NASA)/Jet Propulsion Laboratory (JPL)/California Institute of Technology, US

A quadrupole ion trap mass spectrometer measures precisely the abundance and isotopic composition of small amounts of noble gases.

In this paper, we report a MEMS preconcentrator (PC) -gas chromatograph (GC) that is a crucial part of the Spacecraft Atmosphere Monitor (S.A.M.).The S.A.M. is a highly miniature gas chromatograph -mass spectrometer (GC-MS) for monitoring the atmosphere of crewed spacecraft for both trace organic compounds and the major constituents of the cabin air.The S.A.M. instrument is the next generation of GC-MS, based on JPL's Vehicle Cabin Air Monitor (VCAM), which was launched to the International Space Station (ISS) in April 2010 and successfully operated for two years [1,2].The S.A.M. employs a unique MEMS PC-GC technology that replaces the macro PC-GC unit in the VCAM.We report herein the current progress of the MEMS PC-GC for the S.A.M. instrument.

We report on trace gas and major atmospheric constituents results obtained by the Vehicle Cabin Atmosphere Monitor (VCAM) following almost two years of operation aboard the International Space Station (ISS). VCAM is an autonomous environmental monitor based on a highly compact gas chromatograph/quadrupole ion trap mass spectrometer. It was flown to the International Space Station (ISS) on shuttle mission STS-131 and commenced operations on June 2010. VCAM is capable of providing measurements of both parts-per-billion (ppb) levels of volatile trace-gas constituents, and of the atmospheric major constituents (nitrogen, oxygen, argon, and carbon dioxide) in a space vehicle or station. It is designed to operate autonomously and maintenance-free, approximately once per day, with a self-contained gas supply sufficient for a one-year lifetime. VCAM’s performance is sufficient to detect and identify 90% of the target compounds at their 180-day Spacecraft Maximum Allowable Concentration levels.

Formaldehyde (H2CO) and carbon dioxide (CO2) were produced in collisions of a superthermal, 3 eV beam of H(2S) atoms with CO molecules adsorbed on a gold surface at 4.8 K. The reaction-generated products were detected and analyzed using the techniques of temperature programmed desorption (TPD), quadrupole mass spectrometry, and a novel application of the Metropolis algorithm, random-walk procedure to identify the unique fractionation patterns of H2CO and CO2 from the patterns of other species such as N2, CO, and H2O embedded in the CO blanket and devolved in the TPD/mass spectrometry process. Reaction sequences are given to account for the formation of H2CO and CO2.

Reported herein is development of a quadrupole mass spectrometer controller (MSC) with integrated radio frequency (rf) power supply and mass spectrometer drive electronics. Advances have been made in terms of the physical size and power consumption of the MSC, while simultaneously making improvements in frequency stability, total harmonic distortion, and spectral purity. The rf power supply portion of the MSC is based on a series-resonant LC tank, where the capacitive load is the mass spectrometer itself, and the inductor is a solenoid or toroid, with various core materials. The MSC drive electronics is based on a field programmable gate array (FPGA), with serial peripheral interface for analog-to-digital and digital-to-analog converter support, and RS232/RS422 communications interfaces. The MSC offers spectral quality comparable to, or exceeding, that of conventional rf power supplies used in commercially available mass spectrometers; and as well an inherent flexibility, via the FPGA implementation, for a variety of tasks that includes proportional-integral derivative closed-loop feedback and control of rf, rf amplitude, and mass spectrometer sensitivity. Also provided are dc offsets and resonant dipole excitation for mass selective accumulation in applications involving quadrupole ion traps; rf phase locking and phase shifting for external loading of a quadrupole ion trap; and multichannel scaling of acquired mass spectra. The functionality of the MSC is task specific, and is easily modified by simply loading FPGA registers or reprogramming FPGA firmware.

Measurements are reported for production of CO2 resulting from the impact of a monoenergetic O(P-3) beam upon a surface cooled to 4.8 K and covered with a CO ice. Using temperature-programmed desorption and mass spectrometer detection, one clearly detects increasing amounts of CO2 formation with O(P-3) energies of 2, 5, 10, and 14 eV. This is a measurement of polyatomic molecule formation on a surface in a new regime using superthermal atoms. The chosen surface coverage, surface temperature, and superthermal atom energy simulate conditions in shock-heated circumstellar and interstellar regions.

AbstractThe original article to which this Erratum refers was published in Journal of Mass Spectrometry 2005; 40: 36–42. Copyright © 2005 John Wiley & Sons, Ltd.

A miniature gas chromatograph (GC) and miniature Paul ion trap (PT) mass spectrometer system has been developed for identifying and quantifying chemical species present in closed environments having a complex mixture of gases. Inherent to the system are high sensitivity, good dynamic range, good PT resolution, low GC flow rates to minimize pump requirements and the need for consumables, and the use of a modular approach to, in future work for example, extract and identify volatile organic compounds dissolved in water. Measurements are reported on system response to gaseous species at concentrations varying over four orders of magnitude. The GCPT has a mass, volume, and power that is, conservatively, 1/20th that of commercial off-the-shelf systems. Potential applications are to spacecraft cabin-air monitoring, robotic planetary exploration, and trace-species detection for (terrestrial) residual gas analysis and environmental monitoring.

Miniature gas chromatography (GC) and miniature mass spectrometry (MS) instrumentation has been developed to identify and quantify the chemical compounds present in complex mixtures of gases. The design approach utilizes micro-GC components coupled with a Paul quadrupole ion trap (QIT) mass spectrometer. Inherent to the system are high sensitivity, good dynamic range, good QIT resolution, low GC flow-rates to minimize vacuum requirements and the need for consumables; and the use of a modular approach to adapt to volatile organic compounds dissolved in water or present in sediment. Measurements are reported on system response to gaseous species at concentrations varying over four orders of magnitude. The ability of the system to deal with complicated mixtures is demonstrated, and future improvements are discussed. The GC/QIT system described herein has a mass, volume and power that are, conservatively, one-twentieth of those of commercial off-the-shelf systems. Potential applications are to spacecraft cabin-air monitoring, robotic planetary exploration and trace-species detection for residual gas analysis and environmental monitoring.

Miniaturized chemical instrumentation is needed for in situ measurements in planetary exploration and other spaceflight applications where factors such as reduction in payload requirements and enhanced robustness are important. In response to this need, we are continuing to develop miniaturized GC/MS instrumentation which combines chemical separations by gas chromatography (GC) with mass spectrometry (MS) to provide positive identification of chemical compounds in complex mixtures of gases, such as those found in the International Space Station's cabin atmosphere. Our design approach utilizes micro gas chromatography components coupled with either a miniature quadrupole mass spectrometer array (QMSA) or compact, high-resolution Paul ion trap. Key design issues include high sensitivity, good MS resolution (0.5 amu FWHM or better), low power, robustness, low GC flow rates to minimize vacuum-pumping requirements, and the use of a modular approach to adapt to different environments. Among the potential applications for such instrumentation are in situ detection of astrobiology signatures (using air sampling or ground-drilling techniques), planetary aeronomy, and monitoring of cabin air during duration human flight.

Trace explosives signatures of TNT and DNT have been extracted from multiple sediment samples adjacent to unexploded undersea ordnance at Halifax Harbor, Canada. The ordnance was hurled into the harbor during a massive explosion some 50 years earlier, in 1945 after World War II had ended. Laboratory sediment extractions were made using the solid-phase microextraction (SPME) method in seawater and detection using the Reversal Electron Attachment Detection (READ) technique and, in the case of DNT, a commercial gas chromatograph/mass spectrometer (GC/MS). Results show that, after more than 50 years in the environment, ordnance that appeared to be physically intact gave good explosives signatures at the parts per billion level, whereas ordnance that had been cracked open during the explosion gave no signatures at the 10 parts per trillion sensitivity level. These measure ments appear to provide the first reported data of explosives signatures from undersea unexploded ordnance.