@article {2402, title = {LINEAR QUADRUPOLES IN MASS SPECTROMETRY}, journal = {Mass Spectrometry Reviews}, volume = {28}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 515CWTimes Cited: 5Cited Reference Count: 145Douglas, D. J.}, month = {Nov-Dec}, pages = {937-960}, type = {Review}, abstract = {The use of linear quadrupoles in mass spectrometry as mass filters and ion guides is reviewed. Following a tutorial review of the principles of mass filter operation, methods of mass analysis are reviewed. Discussed are extensions of quadrupole mass filters to higher masses, scanning with frequency sweeps of the quadrupole waveform, operation in higher stability regions, and operation with rectangular or other periodic waveforms. Two relatively new methods of mass analysis the use of "islands of stability" and "mass selective axial ejection" are then reviewed. The optimal electrode geometry for a quadrupole mass filter constructed with round rods is discussed. The use of collisional cooling in quadrupole ion guides is discussed along with ion guides that have axial fields. Finally, mass analysis with quadrupoles that have large distortions to the geometry and fields is discussed. An Appendix gives a brief tutorial review of definitions of electrical potentials and fields, as well as the units used in this article. (C) 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:937-960, 2009}, keywords = {2ND STABILITY REGION, axial fields, AXIAL-FIELD, CHARGED-PARTICLE, COLLISION-INDUCED DISSOCIATION, distorted fields, FRINGING FIELDS, ion guide, ION OPTICAL-PROPERTIES, linear, mass filter, mass scans, multipoles, OCTOPOLE FIELDS, QUADRUPOLE, quadrupole excitation, RADIO-FREQUENCY, RESOLUTION, SEPARATION MODE, STABILITY, TRAJECTORIES, VOLTAGE COMPONENT}, isbn = {0277-7037}, url = {://000271445200005}, author = {Douglas, D. J.} } @article {1097, title = {Linear ion traps in mass spectrometry}, journal = {Mass Spectrometry Reviews}, volume = {24}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 888OJTimes Cited: 73Cited Reference Count: 145}, month = {Jan-Feb}, pages = {1-29}, type = {Review}, abstract = {Linear ion traps are finding new applications in many areas of mass spectrometry. In a linear ion trap, ions are confined radially by a two-dimensional (2D) radio frequency (RF) field, and axially by stopping potentials applied to end electrodes. This review focuses on linear ion trap instrumentation. Potentials and ion motion in linear multipole fields and methods of ion trapping, cooling, excitation, and isolation are described. This is followed by a description of various mass discrimination effects that have been reported with linear ion traps. Linear ion traps combined in various ways with three-dimensional (3D) traps, time-of-flight (TOF) mass analyzers, and Fourier transform ion cyclotron resonance mass spectrometers are then given. Linear ion traps can be used as stand alone mass analyzers, and their use for mass analysis by Fourier transforming image currents, by mass selective radial ejection, and by mass selective axial ejection are reviewed. (C) 2004 Wiley Periodicals, Inc.}, keywords = {analysis, CYCLOTRON-RESONANCE, ELECTROSPRAY-IONIZATION, EXCITATION, EXTERNAL ACCUMULATION, FRINGING FIELDS, INVERSE FOURIER-TRANSFORM, ion traps, linear multipoles, mass, MOLECULE REACTION, OCTOPOLE FIELDS, OF-FLIGHT, QUADRUPOLE, RADIOFREQUENCY, RESONANCE, space charge, STORAGE ASSISTED DISSOCIATION, SYSTEM}, isbn = {0277-7037}, url = {://000226383800001}, author = {Douglas, D. J. and Frank, A. J. and Mao, D. M.} }