Control of Chemical Mass Shifts in the Quadrupole Ion Trap through Selection of Resonance Ejection Working Point and rf Scan Direction

2000 ◽  
Vol 72 (13) ◽  
pp. 2677-2683 ◽  
Author(s):  
J. Mitchell Wells ◽  
Wolfgang R. Plass ◽  
R. Graham Cooks
Keyword(s):  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Resonance Ejection ◽  
Mass Shifts ◽  
Selection Of ◽  
Working Point

Chemical mass shifts in resonance ejection experiments in the quadrupole ion trap

2002 ◽  
Vol 37 (10) ◽  
pp. 1051-1058 ◽  
Author(s):  
Hongyan Li ◽  
Wolfgang R. Plass ◽  
Garth E. Patterson ◽  
R. Graham Cooks
Keyword(s):  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Resonance Ejection ◽  
Mass Shifts

Controlled variation of boundary-activated ion fragmentation processes in a quadrupole ion trap

1994 ◽  
Vol 72 (3) ◽  
pp. 966-976 ◽  
Author(s):  
Raymond E. March ◽  
Mark R. Weir ◽  
Frank A. Londry ◽  
Silvia Catinella ◽  
Pietro Traldi ◽  
...  
Keyword(s):  
Ion Trap ◽  
General Procedure ◽  
Stability Boundary ◽  
Quadrupole Ion Trap ◽  
Molecular Ions ◽  
Resonance Excitation ◽  
Cooling Period ◽  
Ion Fragmentation ◽  
Collisional Cooling ◽  
Working Point

Fragmentation in a quadrupole ion trap of each of two isomeric molecular ions, obtained from 4-nitro-o-xylene and 4-nitro-m-xylene, has been investigated. It is demonstrated that the degree of fragmentation may be controlled by prolongation of both the duration for which the working point of the mass-selected species is held in the vicinity of a stability boundary and a prior collisional cooling period. The extent of fragmentation has been found to increase as the working point is held near the βz = 0 stability boundary while the relative abundances of fragment ions can be varied with the duration of the collisional cooling period. Under appropriate conditions for 4-nitro-o-xylene, >94% of the isolated ions can be fragmented; <5% of the ions are lost from the ion trap while 1% remain intact. As 99% of the charge of the fragmented ions is retained in the ion trap, the overall optimum efficiency of boundary-activated dissociation is >93%; the corresponding efficiency for 4-nitro-m-xylene is 74%. 50% of the selected ions can be fragmented in ≤3 ms. The results are compared with collision-activated dissociation studies carried out with a triple stage quadrupole–hexapole–quadrupole instrument. This technique of boundary-activated dissociation provides a general procedure which does not require careful tuning of the instrument as is required for the more commonly-used technique of resonance excitation.

Theory of high-resolution mass spectrometry achieved via resonance ejection in the quadrupole ion trap

1992 ◽  
Vol 64 (13) ◽  
pp. 1434-1439 ◽  
Author(s):  
Douglas E. Goeringer ◽  
William B. Whitten ◽  
J. Michael. Ramsey ◽  
Scott A. McLuckey ◽  
Gary L. Glish
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Ion Trap ◽  
High Resolution Mass Spectrometry ◽  
Quadrupole Ion Trap ◽  
Resonance Ejection ◽  
High Resolution Mass ◽  
Resolution Mass

Computer Simulation of the Operation of a Three-Dimensional Quadrupole Ion Trap

1992 ◽  
Vol 46 (12) ◽  
pp. 1769-1779 ◽  
Author(s):  
Ce Ma ◽  
Heewon Lee ◽  
David M. Lubman
Keyword(s):  
Computer Simulation ◽  
Ion Trap ◽  
Three Dimensional ◽  
Mass Range ◽  
External Source ◽  
Quadrupole Ion Trap ◽  
Operating Conditions ◽  
Resonance Ejection ◽  
Buffer Gas ◽  
High Kinetic Energy

A computer simulation of the motion of ions in a three-dimensional (3-D) quadrupole ion trap has been performed with a Gateway 386 PC/AT computer. The SIMION program was used as the main program to calculate the potential array of the ion trap space. Several user-written programs were interfaced to the SIMION program to simulate the effects of changing various operating conditions, such as the radio-frequency (rf) potential, the collisional buffer gas, external ion injection, dc ejection from the trap, and resonance ejection. With the use of this simulation, the total storage mass range could be obtained as a function of rf voltage and frequency. The simulations show, as expected, that the collisional buffer gas plays an important role in both stabilizing the trajectory of high-kinetic-energy ions (hot ions) inside the ion trap and trapping ions injected from an external source. Several different buffer gases were studied for their effects upon the trapping motion. In addition, both the total mass ejection that results from applying a dc pulse on the output end-cap electrode and the ion ejection that results from applying an rf frequency to the end cap to produce resonance ejection were also studied with this simulation program. It is demonstrated that a simple PC computer using a modified SIMION program provides results very similar to those expected from theory or from previous work.

Mass shifts due to ion/ion interactions in a quadrupole ion-trap mass spectrometer

1994 ◽  
Vol 8 (6) ◽  
pp. 451-454 ◽  
Author(s):  
Curtis D. Cleven ◽  
Kathleen A. Cox ◽  
R. Graham Cooks ◽  
M. E. Bier
Keyword(s):  
Mass Spectrometer ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Ion Trap Mass Spectrometer ◽  
Ion Interactions ◽  
Mass Shifts
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