Mass spectrometry instrument designs

Selected topics in Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry instrumentation are discussed in depth, and numerous analytical application examples are given. In particular, optimization ofthe single-cell FTMS design and some of its analytical applications, like pulsed-valve Cl and CID, static SIMS, and ion clustering reactions are described. Magnet requirements and the software used in advanced FTICR mass spectrometers are considered. Implementation and advantages of an external differentially-pumped ion source for LD, GC/MS, liquid SIMS, FAB and LC/MS are discussed in detail, and an attempt is made to anticipate future developments in FTMS instrumentation. 

Although the software running on the two platforms can control the same mass spectrometry instruments, their designs are very different. The MassChrom software was designed in the early 1990s for operators with mass spectrometry training the terminology and instrument setup within the applications are specialist for trained mass spectrometrists. 

Meteor can be interfaced with the MetaboLynx mass spectrometer software from Waters Corporation to integrate mass spectrometry data from metabolism studies directly. MetaboLynx is part of the Waters MassLynx Application Managers, a suite of mass spectrometry instrument software [16]. It is designed for automated metabolism studies with data from LC/MS or LC/MS/MS time-of-flight (TOP) experiments. MetaboLynx is able to detect peaks in an LC/MS data file resulting from in vitro or in vivo biotransformation and provides a list of elemental formulae for unidentified components in a mass spectrum. Meteor uses these data to filter the list of predicted metabolites. System requirements are similar to DEREK for Windows. 

In a separate set of experiments designed to follow the gas phase reactions of CHj-radicals with NO, CHj- radicals were generated by the thermal decomposition of azomethane, CHjN NCHj, at 980 °C. The CH3- radicals were subsequently allowed to react with themselves and with NO in a Knudsen cell that has been described previously [12]. Analysis of intermediates and products was again done by mass spectrometry, using the VIEMS. Calibration of the mass spectrometer with respect to CH,- radicals was carried out by introducing the products of azomethane decomposition directly into the high vacuum region of the instrument. 

The largest increase in experimental measurements on aqueous solutions has been in those designed to furnish information on molecular interactions and order. These techniques, along with the kinds of information which can be derived from them, are outlined in Figure 5. Although the principles behind all these techniques have been known for many years, advances in instrumentation and in data collection have encouraged their widespread application to solutions of all kinds. The use of mass spectrometry to study interactions between isolated solvent and solute molecules has been perfected largely within the past ten years. This topic is reviewed in reference (113). 

To avoid the kind of problems which trouble whole-molecule mass spectrometry it is better to use instrumentation especially designed for high precision measurements of isotope ratios isotope-ratio mass spectrometry (IRMS). 

Recent developments in instrument design have led to lower limits of detection, while new ion activation techniques and improved understanding of gas-phase ion chemistry have enhanced the capabilities of tandem mass spectrometry for peptide and protein structure elucidation. Future developments must address the understanding of protein-protein interactions and the characterization of the dynamic proteome (Chalmers and Gaskell 2000). 

In 2006 Beauchamp reported on the expanding role of mass spectrometry in developing new instruments for laboratory simulations and in situ exploration of the space environment.13 The cometary and interstellar dust analyzer ( ), which was designed for the direct analysis of the space environment and mounted on the spacecraft, is a time-of-flight mass spectrometer for measuring, in situ, the chemical composition and the original mass of the individual dust grains. 

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