Controlled ion fragmentation in a 2-D quadrupole ion trap for external ion accumulation in ESI FTICR mass spectrometry

AbstractUndesired fragmentation of electrospray generated ions in an rf multipole traps can be problematic in many applications. Of special interest here is ion dissociation in a 2-D quadrupole ion trap external to a Fourier transform ion cyclotron resonance mass spectrometer (FTICR MS) used in proteomic studies. In this work, we identified the experimental parameters that determine the efficiency of ion fragmentation. We have found that under the pressure conditions used in this study there is a specific combination of the radial and axial potential well depths that determines the fragmentation threshold. This combination of rf and dc fields appears to be universal for ions of different mass-to-charge ratios, molecular weights, and charge states. Such universality allows the fragmentation efficiency of the trapped ions in the course of capillary liquid chromatography (LC) separation studied to be controlled and can increase the useful duty cycle and dynamic range of a FTICR mass spectrometer equipped with an external rf only 2-D quadrupole ion trap

A dynamic ion cooling technique for FTICR mass spectrometry

AbstractA fast dynamic ion cooling technique based upon the adiabatic invariant phenomenon for Fourier transform ion cyclotron resonance mass spectrometry (FTICR) is presented. The method cools ions in the FTICR trap more efficiently, within a few hundred milliseconds without the use of a buffer gas, and results in a substantial signal enhancement. All performance aspects of the FTICR spectrum, e.g., peak intensities, mass resolution, and mass accuracy, improve significantly compared with cooling based on ion–ion interactions. The method may be useful in biological applications of FTICR, such as in proteomic studies involving extended on-line liquid chromatography (LC) separations, in which both the duty cycle and mass accuracy are crucially important

Now He Belongs to the Ages : A Burkean Analysis of the Abraham Lincoln Funeral Ceremonies

This thesis is a Burkean analysis of the major funeral ceremonies of Abraham Lincoln. The first step was to analyze the funeral ceremonies using Burke\u27s pentad. This study concentrates on the Burkean strategies of properties, ambiguity, spiritualization and silence. It was determined by the author that Lincoln\u27s Funeral arrangements met the qualifications for a dramatic analysis. A Burkean analysis was used because his dramatistic style of rhetoric best fit the circumstances. The analysis covers the twenty days between Lincolns assassination on April 14, 1865 and his burial on May 4, 1865. In the interest of time this study was limited to nonverbal symbols only