Fundamentals of Trapped Ion Mobility （被困的离子迁移的基础）.pdfVIP

B American Society for Mass Spectrometry, 2015 J. Am. Soc. Mass Spectrom. (2016) 27:585Y595 DOI: 10.1007/s13361-015-1310-z RESEARCH ARTICLE Fundamentals of Trapped Ion Mobility Spectrometry Part II: Fluid Dynamics Joshua A. Silveira, Karsten Michelmann, Mark E. Ridgeway, Melvin A. Park Bruker Daltonics, 40 Manning Road, Billerica, MA 01821, USA Abstract. Trapped ion mobility spectrometry (TIMS) is a new high resolution (R up to ~300) separation technique that utilizes an electric field to hold ions stationary against a moving gas. Recently, an analytical model for TIMS was derived and, in part, experimentally verified. A central, but not yet fully explored, component of the model involves the fluid dynamics at work. The present study characterizes the fluid dy- namics in TIMS using simulations and ion mobility experiments. Results indicate that subsonic laminar flow develops in the analyzer, with pressure-dependent gas veloc- ities between ~120 and 170 m/s measured at the position of ion elution. One of the key philosophical questions addressed is: how can mobility be measured in a dynamic system wherein the gas is expanding and its velocity is changing? We noted previously that the analytically useful work is primarily done on ions as they t