SIMS Instrumentation, future

The future of SIMS as an imaging method depends on instrumental and chemical developments. The progress will be focused on special instruments dedicated to very... 

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. 

The current pace of instrument development is such that these snmmarized comments will prohahly have to be rewritten sooner rather than later. The potential role of the 2D traps in quantitative analyses was already mentioned and very recently a modification to a QqTOF instrument that permits SIM/MRM operation with high duty cycle has been described the higher product ion resolution could be useful in bioanalytical and similar assays where isobaric interferences from unknown metabolites could be a factor. However, it seems likely that, for the apphcations of interest in this book, the triple quadrupole instrument will remain the workhorse instrument of choice for the foreseeable future. The recent introduction of a triple quadrupole design in which Qj is capable of enhanced RP (peak widths as low as 0.1-0.2Th) permits increased selectivity via precursor ion selection. 

Clearly, the briefly reviewed complementary spectroscopic techniques are important to approach these current shortcomings in a rational manner for practical purposes. For future progress significant technical refinements for, e.g. XPS and SIMS imaging, will enhance the spatial resolution and will lead to new opportunities. However, the costs for the equipment and instrumentation may limit the widespread application of these approaches compared to AFM-based techniques. 

---