Mass Spectra Deconvolution of Gaseous Mixtures Containing Volatile Organic Compounds

The Spacecraft Atmosphere Monitor (S.A.M.) is a highly compact gas chromatograph mass spectrometer (GCMS) that will analyze the spacecraft atmosphere for all volatile organic compounds (VOCs). In the Trace Gas Analysis (TGA) mode of operation the S.A.M will detect and quantify VOCs from 50 to 10,000 parts-per-billion. GCMS mass spectra from 20 to 360 Th are generated at a rate of twenty full mass spectra per second and GC co-elutions can yield overlapping electron-impact mass spectra. Despite the presence of these molecular isobars, we report herein on the S.A.M. deconvolution algorithms that have been developed and are capable of identifying target species based on their characteristic fragmentation patterns. We investigate the efficiency of deconvolution algorithm as a function of mass resolution with which mass spectrum is acquired. Finding the balance between deconvolution accuracy and generated data volume under time constrains and limited computing resources is the main topic of this study.