Electrospray Mass Spectrometry for In-Orbit Biomolecule Analysis

Here we describe a suite of experiments probing the ability of ESI propulsion sources to serve as TOF-MS ionization stages in pure vacuum operation. The goals of the study are to assess the operational parameter space which may result in biomolecules entrained in an ion spray, detectable by traditional mass spectrometry techniques. The variables explored in this work include the ionic liquid solvents EMI-BF4 and EMI-Am, and biomolecules arginine and cellulose. A laboratory ESI source is coupled with a TOF-MS capable of providing a mass resolution (m/dm) between 200 and 1000 for the ion range of interest (100–500 amu), The ion spray is characterized with the solvent alone and with the biomolecules mixed in. Initial experiments indicate that cellulose may be detectable at high concentrations in EMI-BF
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while operation with EMI-Am may require heating above room temperature.