Filtered noise fields

Figure 8 Dissociation of (a) glow discharge generated copper dimer ions using a filtered noise field results in (b) bare copper product ions.

DE Goeringer, KG Asamo, SA McLuckey, D Hoekman, SW Stiller. Filtered noise field signals for mass-selective accumulation of externally-formed ions in a quadrupole ion trap. Anal Chem 66 313—318, 1994. 

The instrument used in these analyses was a modified version of the Finnigan ion trap mass spectrometer (ITMS) running ICMS software and coupled with a Teledyne HST-1000 filtered noise field system. The end caps of the IT were modified with larger apertures (5 mm) that were covered with spot-welded 90% pass grids. The instrument was operated in the negative-ion mode. 

Ion isolation was achieved using a filtered noise field applied to the end caps to achieve capture of a mass range of approximately 10 u centered on the ion of interest. The voltage of the field was adjusted such that unwanted ions were ejected, without unduly compromising the intensity of the ions of interest. 

SM Gordon, PJ Callahan, DV Kenny, JD Pled. Direct sampling and analysis of volatile organic compounds in air by membrane introduction and glow discharge ion trap mass spectrometry with filtered noise fields. Rapid Commun Mass Spectrom 10 1038-1046, 1996. 

Eiden, G. C., Barinaga, C. J., and Koppenaal, D. W. (1995) Selective ion accumulation in an ICP/ITMS using a filtered noise field. In Proceedings of the 43rd ASMS Conference on Mass Spectrometry and Allied Topics, Atlanta, GA. 

Kenny, D. V, Callahan, P. J., Gordon, S. M., and StiUo-, S. W. (1993) Simultaneous isolation of 2 different M/Z ions in an ion-trap mass-spectrometer and their tand mass-spectra using filtered-noise fields. Rapid Commun. Mass Spectrom., 7(12), 1086-9. 

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