Apparatus and method for cross-flow ion mobility spectrometry

摘要

A cross-flow ion mobility spectrometer consists of two parallel plates defining a volume between them. Analyte ions flow along an axis from an entrance end to an exit end through the volume. An RF confining field tends to guide ions along the axis. An analytical gas flow is established orthogonal to the axis. A DC electrostatic analytical field is oriented in opposition to the analytical gas flow such that the “drag force” on ions of the selected mobility due to the analytical gas flow is balanced by the force on the ions due to the electrostatic analytical field. The selected ions are thereby able to follow a stable path to the exit end of the cross-flow mobility analyzer. However, the force on ions of other than the selected mobility is unbalanced and these ions are deflected and lost.

主权项

1. An apparatus for the mobility analysis of ions comprising:
means for generating a first and second electric field in a volume in a manner so that the first electric field confines ions to a longitudinal axis along at least one direction orthogonal to the said axis and the second electric field is a DC field orthogonal to the longitudinal axis; and a duct forming a gas flow path in the volume, the gas flow having a velocity component orthogonal to the longitudinal axis so that a first force generated on the ions by the DC field counteracts a second force generated on the ions by the orthogonal velocity component of the gas flow.