IMS-MS Using Traveling Wave Ion Guide Devices

The initial setup was developed into a hybrid quadrapole-ion-mobility-TOF instrument [148], The collision cell region of this instrument features three traveling-wave stacked ring ion guides, of which the middle one is used as ion-mobility drift tube and the other two may be used as collision cell, when applicable. The 185 imn long IMS part is operated at pressures up to 1 mbar with up to 200 ml/min Ar whereas the collision cells are 100 mm long and operated at 10 mbar with up to 10 ml/min gas [148]. The system can be used for a wide variety of applications. 

The term high-pressure mass spectrometry (HP-MS) has been used in various contexts over the years. In many studies, the term refers to performing MS experiments with a high-pressure or atmospheric pressure ion source in combination with a high-vacuum mass analyzer (in contrast to the high-vacuum ion source), whereas in some studies the actual mass analysis is also performed at higher pressures as well, e.g., at 1 mbar. 

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