Patent ID: 7985949
Filing Date: 2011-07-26
Classification: G01N

Abstract:
1. An ion mobility spectrometer for detecting an analyte in a gas phase sample, said spectrometer comprising: a. an inlet for introducing said gas phase sample containing said analyte to an ionization region having an ionization source; b. a source of dopant in fluid communication with said ionization region, wherein said ionization source generates ions from said analyte and dopant; c. a separation region in fluid communication with said ionization region and said source of dopant, for receiving and separating said generated ions on the basis of ion mobility; and d. a detector positioned in fluid communication with said separation region for receiving and detecting said ions on the basis of ion mobility, wherein said dopant in said separation region is in excess, and at a dopant to analyte ratio in the separation region that is greater than 1000, and said dopant is continuously introduced to said separation region thereby providing at least a portion of said separation region with excess dopant.