Indiana University

Michael A Ewing

David E Clemmer

Steven M Zucker

Christopher R P Conant

An ion mobility spectrometer includes a drift tube responsive to application of at least a first voltage to establish a first electric field therein configured to cause ions within the drift tube to move along and about the drift tube while separating from one another as a function of ion mobility, and a transition region coupled to opposed ends of the first drift tube such that the drift tube and the transition region together define a closed path. The transition region is responsive to application of at least a second voltage to cause the ions to move along and about the closed path, to application of at least a third voltage to selectively pass ions into the drift tube and to application of at least a fourth voltage to selectively pass ions out of the drift tube.

Closed path ion mobility spectrometer having a common ion inlet and outlet

A hybrid ion mobility spectrometer includes a single-pass drift tube having an ion inlet and an ion outlet, a multiple-pass drift tube having an ion inlet and an ion outlet each coupled to the single pass drift tube between the ion inlet and the ion outlet thereof, and at least one ion steering channel controllable to selectively pass ions traveling through the single-pass drift tube into the multiple-pass drift tube via the ion inlet of the multiple-pass drift tube and to selectively pass ions traveling through the multiple-pass drift tube into the single-pass drift tube via the ion outlet of the multiple-pass drift tube. The single-pass drift tube separates in time ions traveling therethrough according to a first function of ion mobility, and the multiple-pass drift tube separates in time ions traveling one or more times therethrough according to the first or a second function of ion mobility.

Hybrid ion mobility spectrometer

An ion mobility spectrometer instrument has a drift tube that is partitioned into a plurality of cascaded drift tube segments. A number of electric field sources may each be coupled to one or more of the plurality of drift tube segments. A control circuit is configured to control operation of the number of the electric field sources in a manner that sequentially applies electric fields to the drift tube segments with a magnitude of at least one being different than the others to allow only ions having a predefined ion mobility or range of ion mobilities to travel through the drift tube. Alternatively, the length of at least one of the drift tube segments may be made different from those of the others to produce the same result. The drift tube segments may define a linear drift tube or a closed drift tube with a continuous ion travel path.

Ion mobility spectrometer and method of operating same

In a linear drift tube partitioned into a plurality of cascaded drift tube segments each followed by an ion elimination region, a system and method of separating ions includes repeatedly establishing electric drift fields in the drift tube segments and in some of the ion elimination regions while establishing electric repulsive fields in others of the ion elimination regions such that ions having a predefined mobility or range of mobilities are transmitted through the drift tube in one direction, and when the ions reach the end of the drift tube the electric drift fields are reversed and the process is repeated to transmit the ions to the opposite end of the drift tube. Ions may be made to pass back and forth through the drift tube any number of times before being drawn out of the drift tube to an ion detector or into another drift tube.

A hybrid ion mobility spectrometer includes a single-pass drift tube having an ion inlet at one end and an ion outlet at an opposite end, a multiple-pass drift tube having an ion inlet and an ion outlet each coupled to the single pass drift tube between the ion inlet and the ion outlet thereof, and a set of ion gates each controllable between an open position to pass ions therethrough and a closed position to block ions from passing therethrough. The set of ion gates may be controlled to pass at least some ions traveling through the single-pass drift tube into the multiple-pass drift tube via the ion inlet of the multiple-pass drift tube and to pass at least some ions traveling through the multiple-pass drift tube into the single-pass drift tube via the ion outlet of the multiple-pass drift tube.

In a drift tube partitioned into a plurality of cascaded drift tube segments each followed by an ion elimination region, a method of separating ions as a function of ion mobility includes repeatedly, and alternating between at least two different time durations, establishing electric drift fields in the drift tube segments and in some of the ion elimination regions while establishing electric repulsive fields in others of the ion elimination regions such that ions having a predefined mobility or range of mobilities are transmitted through the drift tube at one or more frequencies which include one or more overtones of a fundamental frequency at which ions having the predefined mobility or range of mobilities are transmitted through the drift tube with the electric drift fields and electric repulsive fields repeatedly established with uniform time durations.

In a drift tube partitioned into a plurality of cascaded drift tube segments each followed by an ion elimination region, for any integer M greater than 1, a method of separating ions repeats the following multiple times to cause only ions entering the drift tube that have a predefined ion mobility or range to traverse the drift tube: for each integer N beginning with 1 and sequentially advancing to M, establishing for a time duration an Nth electric repulsive field in the Nth ion elimination region and in every following Mth ion elimination region and an Nth electric drift field in each remaining ion elimination region and in each drift tube segment while deactivating for the time duration all non-Nth electric drift fields and non-Nth electric repulsive fields in each of the ion elimination regions and drift tube segments.

An ion mobility spectrometer instrument has a drift tube that is partitioned into a plurality of cascaded drift tube segments. A number of electric field activation sources may each be coupled to one or more of the plurality of drift tube segments. A control circuit is configured to control operation of the number of electric field activation sources in a manner that sequentially applies electric fields to the drift tube segments with a activation duration of at least one of the electric field activation sources different than that of the others to allow only ions having a predefined ion mobility or range of ion mobilities to travel through the drift tube. The drift tube segments may define a linear drift tube or a closed drift tube with a continuous ion travel path.

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Bloomington, IN, United States of America

Michael A Ewing