A modular data and control system to improve sensitivity, selectivity, speed of analysis, ease of use, and transient duration in an external source FTICR-MS

Abstract

We present here a new Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) controller designed and constructed to meet the growing need for increased speed, memory, and ease of use. The system realizes these goals via the first published application of fast PXI bus technology and by employing a graphical user interface (GUI) for control of all aspects of ion production, delivery, containment, manipulation of internal and kinetic energies, and measurement in an external source instrument. Additionally, new hardware for monitoring and control of these aspects and for processing extended datasets both to and from the instrument have been implemented. The modular nature of the control hardware makes the instrument platform, in this case a modified external source 7T FTICR-MS, irrelevant. The GUI consists of two separate modules; one provides a temporal representation of the pulses, voltages (rf and dc), and dc heater currents that control all aspects of the experiment while the other provides complex data analysis capabilities and design of excitation waveforms. Real-time monitoring of the transient signal is available in this module as well as near real-time monitoring of the resulting mass spectrum (using a truncated dataset). A PXI bus with 40 digital to analog converters (DAC) and 64 digital (TTL) sources drive the source, optics, and trapping functions of the instrument as well as the other peripheral hardware. Acquisition is realized using a VME bus with a TTL triggered program resident on an embedded processor to minimize dead time. The acquisition system is equipped with 192 MB memory for both excitation and detection waveforms with FIFO buffering to provide full rate bandwidth of 10 MHz, and four digital down converters (DDCs) to enable mixing of heterodyne signals for narrow band measurements completes the ensemble.