US 7,491,930 B2
Hooked differential mobility spectrometry apparatus and method therefore
Alexandre A. Shvartsburg, Richland, Wash. (US); Keqi Tang, Richland, Wash. (US); Yehia M. Ibrahim, Richland, Wash. (US); and Richard D. Smith, Richland, Wash. (US)
Assigned to Battelle Memorial Institute, Richland, Wash. (US)
Filed on Dec. 29, 2006, as Appl. No. 11/617,889.
Prior Publication US 2008/0156978 A1, Jul. 03, 2008
Int. Cl. H01J 49/06 (2006.01); H01J 49/26 (2006.01); B01D 59/44 (2006.01)
U.S. Cl. 250—287  [250/281; 250/282; 250/286; 250/288; 250/293; 250/396 R] 43 Claims
OG exemplary drawing
 
1. An apparatus for improved interfacing of at least one differential mobility spectrometry (DMS) analyzer having substantially planar electrodes to other stages, comprising:
at least two curved electrodes with a gap therebetween filled with a gas and operable for receiving ions introduced thereto, carrying a periodic asymmetric waveform and a dc compensation voltage that jointly establish spatially inhomogeneous electric field in said gap, which focuses said ions toward the median of said gap before and/or after said at least one DMS analyzer; and
wherein the range of DMS separation parameters selected substantially includes that set by operation of said DMS analyzer such that said ions are focused to said gap median without significant losses, creating a thinner ion beam that is more completely transmitted through apertures of limited size to said other stages and/or more effectively injected into said DMS analyzer.