Fourier transform ion cyclotron resonance mass spectrometry: technique developments

Abstract

In the three years since the 11th International Mass Spectrometry Conference, Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry has advanced both theoretically and experimentally with respect to ion formation and transfer to the ion trap, ion trap design and operation, ion excitation and detection, data reduction, and in chemical and analytical applications. In this short review, we shall describe several new ion sources for FT-ICR MS (e.g. high pressure, fast neutral beam, and continuous- flow atom bombardment), various new ion traps employing screens (e.g. for simultaneous trapping of positive and negative ions), guard wires (for improved isotopic abundance accuracy), and multiple sections. In addition, the ICR excitation and detection processes have recently been treated in quite full theoretical detail, leading to improved understanding of the origin and relative magnitudes of signals at multiples and combinations of the three fundamental ion frequencies: cyclotron, magnetron, and trapping. Recent chemical applications of FT-ICR MS have concentrated on ion/molecule chemistry (e.g. clusters, such as C 60), whereas the primary analytical applications have come from laser desorption FT-ICR MS (e.g. polymers, surface analysis).