Increasing the Performance of Portable Ion Mobility Analyzers: Development of the Periodic Focusing Differential Mobility Analyzer (PFDMA)

Abstract

Ion mobility spectrometry (IMS) as a stand-alone technique has become increasingly important for applications in security, defense, and environmental monitoring, and also in biol. applications such as mol. structure and -omic anal. when combined with mass spectrometry. Yet, the majority of these devices are drift cell based and limited by low duty cycles because of ion gating. Differential Mobility Analyzers (DMAs) are attractive alternatives due to their continuous ion transmission and success in analyzing aerosol particles in real time environmental tests. But, the resoln. of a DMA is low due to difficulties in achieving laminar gas flow, low sample gas flow to sheath gas flow ratio, and high velocity sheath gas using small pumps, if portability is a concern. To overcome these challenges, we will introduce a new ion mobility spectrometer that increases the amt. of work done on the ions during sepn. by introducing an elec. field opposing the gas flow direction while simultaneously preserving laminar gas flow. The development of the Periodic Focusing Differential Mobility Analyzer (PFDMA) can lead to a portable device that exhibits both high resoln. and sensitivity, to meet the needs of today's expanding applications. [on SciFinder(R)]