Inverse Ion Mobility Spectrometry

摘要

A novel method is proposed for enhancing the separationnpower of ion mobility spectrometry (IMS) and othernsimilar pulsed techniques, such as time-of-flight massnspectrometry. In this technique, rather than generatingnan ion packet, a dip is created in the ion beam. This isnachieved by an inverse pulse applied to the shutter grid.nThe dip moves with the same velocity as the ion packet,nand the detector reads an inverse peak at the same driftntime as that of the normal operation. Using this technique,nwe achieved 30 60% higher resolution compared to thennormal method. In addition, two close peaks that werennot resolved via normal IMS were well resolved to thenbaseline using this technique. The main reason for thenincreased resolution is likely the absence of space chargenin the dip.