Membrane Inlet Introduction Mass Spectrometry

The core development of MIMS has centered upon MS ionization techniques for the analysis of aromatic contaminants in water,47 improving membrane extraction selectivity48 and enhancing MIMS sensitivity by cooling and heating the membrane (trap and release MIMS).49 50 A dedicated review has been written on the applications of MIMS in environmental analysis.51 

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Nonporous polymeric membranes have been incorporated as sample inlets in mass spectrometry (MS) for the direct sampling of volatile and semivolatile organic compounds (VOCs and SVOCs). The technique of membrane inlet (introduction) mass spectrometry (MIMS) has achieved tremendous success in the last two decades in terms of instrumentation and applications. Figure 4.1 depicts the experimental setup of (i) in-sample membrane MIMS and (ii) direct insertion (near the ion source in MS) membrane MIMS. 

MIMS membrane inlet (introduction) mass spectrometry... 

Another MS technique used in connection to pyrolysis is MIMS (membrane introduction mass spectrometry). MIMS is in fact a special inlet for the mass spectrometer, where a membrane (usually silicone, non-polar) lets only certain molecule types enter the Ionization chamber of the MS. This allows, for example, direct analysis of certain volatile organic compounds from air. The system makes possible the coupling of atmospheric pyrolysis to a mass spectrometer [61a] allowing direct sampling of the pyrolysate. Other parts of the mass spectrometer do not need to be changed when using MIMS. 

Viktorova, O.S., Kogan, V.T., Manninen, S.A., Kotiaho, T., Ketola, R.A., Dubenskii, B.M., Parinov, S.P., Smirnov, O.V. Utilization of a multimembrane inlet and a cyclic sudden sampling introduction mode in membrane inlet mass spectrometry. J. Am. Soc. Mass Spectrom. 15, 823-831 (2004)... 

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