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The recent development of a collection of techniques referred to as direct sampling ion trap mass spectrometry (DSITMS) shows great promise for real-time, high-throughput, low-cost screening of environmental pollutants in air. One of its great strengths is the flexibility it allows the user in choosing among different sample introduction systems, ionization modes, and scan modes. This paper delineates the various stages involved in a DSITMS analysis, describes the options and great flexibility inherent in each of these stages, and demonstrates the use of DSITMS techniques for monitoring trace levels of volatile organic compounds (VOCs) in Mir space station air samples.

A system based on expert systems and ion trap mass spectrometry has been developed to monitor air quality for life support applications. Three different analytical techniques, Thermal Desorption/Gas Chromatography/Mass Spectrometry (TD/GC/MS), Gas Chromatography/Mass Spectrometry (GC/MS), and Mass Spectrometry/Mass Spectrometry (MS/MS), were implemented on this system and evaluated with respect to their potential utility for monitoring major atmospheric constituents, trace levels of known contaminants, and trace levels of unknown compounds in closed environments. TD/GC/MS is an excellent method for characterizing ultratrace levels of volatile organic compounds (VOC's) and has been employed for off-line analysis of air samples collected during several space missions. GC/MS is perhaps the most commonly used method for the analysis of complex mixtures and is currently under development for on-line monitoring of trace contaminants for the space station.

Efforts to develop sensor and control system technology to monitor air quality for life support have resulted in the development and preliminary testing of a concept based on expert systems and ion trap mass spectrometry (ITMS). An ITMS instrument provides the capability to identify and quantitate a large number of suspected contaminants at trace levels through the use of a variety of multidimensional experiments. An expert system provides specialized knowledge for control, analysis, and decision making. The system is intended for real-time, on-line, autonomous monitoring of air quality. The key characteristics of the system, performance data and analytical capabilities of the ITMS instrument, the design and operation of the expert system, and results from preliminary testing of the system for trace contaminant monitoring are described.