A QUADRUPOLE ION TRAP DEVICE, METHODS OF OPERATING THE ION TRAP DEVICE AND A MASS SPECTROMETER INCLUDING THE ION TRAP DEVICE

摘要

A quadrupole ion trap device has a field adjusting electrode located outside the trapping region adjacent the aperture in the entrance end cap electrode, and optionally adjacent the aperture in the exit end cap electrode. The field adjusting electrode(s) controls field distortion in the vicinity of the apertures. By appropriately setting the voltages on the field adjusting electrodes the efficiency and resolution of operational processes such as ion introduction, precursor ion isolation and mass scanning can be improved.