METHOD FOR SELECTIVE COLLISION DISSOCIATION USING BORDER EFFECT EXCITATION WITH CONVENTIONAL COOLING TIME CONTROL

摘要

PURPOSE: To avoid disorder of ion paths and suppress an ultimate ion loss and expansion of the trap size by taking cooling time for ions in ionization process in a quadrupole ion trap to form a high signal-to-noise ratio. CONSTITUTION: This method is to selectively dissociate parent ions by collision dissociation in a quadrupole ion trap (hereafter called as a trap) and comprises the following processes (a)-(f): (a) introducing a buffer gas into the trap; (b) injecting a sample gas to be analyzed into the trap; (c) applying at least an RF field with an amplitude V and d.c. potential U to capture ions with a selected mass/charge ratio in a selected stabilized operation mode of the trap; (d) ionizing the sample; (e) continuously carrying out the application of the RF field at selected various time intervals; and (f) adjusting the amplitude V or the potential U to assume the value of the energy from the RF filed to be transmitted non-resonant manner to the selected ions.