Patent ID: 8164056
Filing Date: 2012-04-24
Classification: H01J

Abstract:
1. A method for operating an ion trap to react analyte ions therein, comprising: (a) providing a multipole rod system having an axis and divided into at least a first segment, a middle segment and a last segment positioned along the axis; (b) operating the multipole rod system as a linear ion trap with a constant field distribution along the axis; (c) introducing and storing analyte ions within the linear ion trap; (d) supplying a single-phase RF voltage to all rods of the middle segment thereby forming a three-dimensional ion trap from the middle segment that collects the analyte ions in a spherical cloud; (e) performing a reaction with the analyte ions in the three-dimensional ion trap to form product ions; and (f) ejecting the product ions from the three-dimensional ion trap for subsequent mass analysis.