High-field asymmetric waveform ion mobility spectrometer

R.A. Miller, G.A. Eiceman, E.G. Nazarov and A.T. King, A micro-machined high-field asymmetric waveform-ion mobility spectrometer (FA-IMS), Sensor and Actuators B. Chemical, 67 (2000) 300—306. www.sionex.com (click to products)... 

E. G. Nazarov, and A. T. King, A Micro-Machined High-Field Asymmetric Waveform-Ion Mobility Spectrometer (FA-IMS), Sens. Actuators B Chem. 

FIGURE 6.5 Drift tubes for FAIMS or DMS including the configuration commercialized by Thermo Fisher Scientific (a) with a cylindrical shape (with permission from Thermo Fisher Scientific) the first small planar design commercialized by Sionex, Incorporated (b) (from Miller et al., A novel micro-machined high field asymmetric waveform ion mobility spectrometer, Sens. Actuators B 2000 with permission) and the microfabricated, very small structures of the ultraFAlMS (c) manufactured by Owlstone Nanotechnology (from Owlstone White Paper, 2006). 

Gneviemont, R. Pnrves, R.W., Atmospheric pressnre ion focnsing in a high-field asymmetric waveform ion mobility spectrometer. Rev. Sci. Instrum. 1999, 70, 1370-1383. 

Guevremont, R., Purves, R.W., Atmospheric pressure ion focusing in a high-field asymmetric waveform ion mobility spectrometer. Rev. Set Instrum. 1999, 70, 1370. Kudryavtsev, A., Makas, A., Ion focusing in an ion mobiUty increment spectrometer (IMIS) with non-uniform electric fields fundamental considerations. Int. J. Ion Mobility... 

Mass spectrometrists have always been concerned with the measurement of the mass and intensity of analyte ions. Investigation/utilization of the shapes of molecules is now possible with ion mobility techniques that utilize differences in the cross sections of ions as they move through a gas. Think in terms of two pieces of paper, one crumpled and the other flat. If dropped at the same time, the crumpled one will hit the floor first because it will encounter less air resistance than the flat piece. A similar situation applies to ions with different shapes as they travel through a gas. Although ion mobility has been examined with home-built instruments for years, only recently has this type of analyzer become available commercially. There are two significantly different types, the high-field asymmetric waveform ion mobility spectrometer (FAIMS) and the ion mobility separator (IMS). The FAIMS separator is placed between the ion source and the analyzer, while the IMS cell is located between the analyzers of an MS/MS instrument. 

High-Field Asymmetric Waveform Ion Mobility Spectrometer (FAIMS)... 

FIGURE 2.31 High-field asymmetric waveform ion mobility spectrometer (FAIMS) analyzer. 

One recent development that offers scope for direct injection of aqueous samples into an MS system is the high-field, asymmetric waveform ion mobility spectrometer (FAIMS). By interfacing the FAIMS technology to an ESI—MS instrument a significant reduction in detection limits has been achieved for molecules of <300 Da. Preconcentration is unnecessary and analytical times are significantly shortened. Recent appHcations of this technique include naphthenic and haloacetic acids in water and amphetamines, morphine and codeine... 

While the majority of separahons are carried out with chromatographic processes, recent advances in the design of ion-mobility instruments provide a crude means to frachonate samples that enter the mass spectrometer based on molecular size and three-dimensional (3D) shape, rather than mass to charge or polarity. The use of high-field asymmetric-waveform ion-mobility... 

FIGURE 9.13 Schematic of ESI-FAIMS instrument interfaced to quadrupole mass spectrometer (QMS). (From Purves and Guevremont, Electrospray ionization high-field asymmetric waveform ion mobility spectrometry-mass spectrometry. Anal. Chem. 1999, 71(13) 2346-2357. With permission.)... 

R. W. Purves, D. A. Bamnett, B. Ells, and R. Guevermont, Investigation of bovine ubiquitin conformers separated by high-field asymmetric waveform ion mobility spectrometry cross section measurements using energy-loss experiments with a triple quadrupole mass spectrometer, 7. Am. Soc. Mass Spectrom. 11, 738-745 (2000). 

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