Method for separating ions according to a physicochemical property

摘要

A method of separating ions according to a physicochemical property is disclosed. The method comprises causing ions to perform a plurality of cycles along or around an ion guiding path such that the ions separate according to said physicochemical property. The ions are ejected from an ion exit region by applying a force to the ions such that only having a physicochemical property value that is either above or below a threshold value are ejected as they pass through the exit region, but ions having a physicochemical property value either below or above said threshold value, respectively, remain within the ion guiding path. The force applied to the ions within the exit region is varied with time such that the physicochemical property value of the ions ejected from the ion guiding region varies with time.