Ion trap technology

Compatibility with existing injection techniques and ion trap technology... 

Stafford, G.C. Recent improvements in and analytical applications of advanced ion trap technology. Finnigan MAT IDT 16. 

Stafford, G.C. Advanced ion trap technology in an economical detector from GC. Finnigan MAT IDT 20. 

In the ion trap technology, ions are captured in three-dimensional electric fields. The continuous beam of ions fills the trap up to the limit of their space charge. When additional electric fields are applied, ions are ejected sequentially and detected. Accumulation of ions in the trap results in high sensitivity for these instruments. The trap can be operated in MS and MS/MS modes. In the latter, the ions of interest are maintained in the trap, whereas the other ions are excluded. Sequential fragmentation steps can be performed to generate MSn spectra, highly valuable for structural characterization studies. 

Griffiths, I.W. Recent Advances in Ion-Trap Technology. Rapid Commun. Mass Spectrom. 1990, 4, 69-73. 

Weber-Grabau, M. Kelley, P. Bradshaw, S. Hoekman, D. Evans, S. Bishop, P. Recent advances in ion-trap technology. Adv Mass Spectrom. 1989, llA., 152-153... 

Commercially available GC-MS systems present major differences in their detection and recording system. Many quadrupole instruments use SIM for the determination of analytes at trace levels. With this type of instrumentation, more than 1-10 ng of the analyte is required to record a full-scan mass spectrum. In contrast, instruments based on ion-trap technology can record a full-scan mass spectrum on an analyte at pg level. With SIM, a limited number of ions are monitored during a selected time interval of the chromatogram. The presence of the analyte is determined by the presence of these diagnostic ions at the correct retention time and in the correct abundance ratio (33). 

Stafford, C.C., Kelly, P.E., Syka, J.E.P., Reynolds, W.E. and Todd, J.F.J. (1 984) Recent improvements in and analytical applications of advanced Ion trap technology. International Journal of Mass Spectrometry and ion Processes 50, 85-98. 

The first direct demonstration of the applicability of alkali ion attachment reactions using a sodium cation emitter as a novel and sensitive technique of ionization for ion trap mass spectrometry was made with an ion trap mass spectrometer equipped with an external ion source to generate the reagent Na ions [28]. The combination of alkali metal ion attachment with an ion trap may well represent a noticeable improvement in the selectivity and sensitivity of current GC ion trap technology, and may enlarge the scope of use of this type of mass spectrometer. 

Typically, MALDl has been performed under low pressure conditions (ca 10 Torr). In recent years, intermediate pressure (IP, 10 to 1 Torr) [10,12-14] and atmospheric pressure (AP) MALDl [15,16] systems have been developed to analyze more labile molecules and for tissue analysis [10]. Atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDl) offers the ability to couple a MALDl source to most commercial instruments, including quadrupole ion traps, because the source uses existing ion optics and vacuum transfer lines of commercial instruments to introduce the ions generated by MALDL A brief discussion of IP-MALDI with ion trap technology is presented, but the primary focus is on the instrumentation aspect of ion trap technology, in particular linear ion trap technology, for direct tissue analysis and imaging MS studies. 

G.C. Stafford, Advanced Ion Trap Technology in an Economical Detector for GC, Finnegan MAT IDT Pnblication 20. 

In a completely different approach to all the above-mentioned studies, von Helden and coworkers have combined ion trap technology with superfluid helium nanodroplets to measure spectra of cold biomolecular ions [59]. As illustrated schematically in Fig. 12, after producing gas-phase biomolecules via electrospray, they mass select them, bend them 90° with a static quadrupole deflector, and then trap them in a room temperature ion trap. A pulsed, helium droplet source produces... 

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