DTIMS Ion Trap Mass Spectrometry

The exception to the rule IMS must be interfaced to MSs through a pinhole leak is when they are interfaced to some type of ion-trapping MS. Because ion traps collect ions for several seconds, IMS mobility resolution is lost. Thus, ion traps such as Paul traps, linear traps, Orbitraps, and FTICR instruments require a mobility-filtering type of IMS. When drift tube IMS instruments are interfaced to trapping MSs, a two ion gate system must be employed to select specific mobilities to trap in the MS. 

Quadrupole Ion Trap 3. Bradbury-Nielsen 1. Electrospray Ionization 

FIGURE 9.11 Schematic of the electrospray ionization, ambient pressure, dual-gate ion mobility, quadrupole ion trap mass spectrometer. This instrument consisted of six primary units an electrospray ionization source, an ion mobility spectrometer, a vacuum interface, ion guides and lenses, a quadrupole ion trap, and a PC-based data acquisition system (not shown). (Reprinted from Glowers and Hill, Mass analysis of mobility-selected ion populations using dual gate, ion mobility, quadrupole ion-trap mass spectrometry. Anal. Chem. 2005, 77, 5877-5885. With permission.) 

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