AN INTRODUCTION TO QUADRUPOLE ION-TRAP MASS-SPECTROMETRY

A concise introduction is presented to the theory and application of q uadrupole ion trap mass spectrometry. The presentation of the theoreti cal treatment is based on a demonstration of the equivalence of the fo rce acting on an ion in a quadrupole field and the force derived from the Mathieu equation; this equivalence permits the application of the solutions of Mathieu's equation to the confinement of gaseous ions. Re sonant excitation, collision-induced dissociation, mass spectrometry, tandem mass spectrometry and chemical ionization are discussed in the context of analytical applications. Sample calculations of the trappin g parameters q(z) and beta(z), the axial secular frequency, mass range , mass range extension and the magnitude of the potential well depth a re given. (C) 1997 by John Wiley & Sons, Ltd.