Flow recirculation for mobility separation improvement
AssigneesThermo Finnigan LLC, Thermo Fisher Scientific (Bremen) GmbH
InventorsMikhail V. Ugarov, Vladimir Gurevich, Pablo Nieto Ramos, Alexander A. Makarov
Life of this patent
Estimating the term…
Abstract
An ion mobility analyser is disclosed having a gas flow directed along the ion travel axis and a set of electrodes to which DC voltages are applied to establish a DC field. The opposing forces of the gas flow and DC field cause ions to be trapped within a separation region in axial regions determined by their ion mobilities. A gas recirculator, having inlet and outlet ends respectively located downstream and upstream of the separation region, supplies at least fifty percent of the gas flow within the separation region, thereby reducing vacuum pumping requirements.
Claims20
An ion mobility analyser, comprising:
- a mobility separation cell including a set of electrodes defining an ion separation region, wherein the mobility separation cell is configured to be at sub-atmospheric pressure when in operation, and the mobility separation cell having:
- an ion inlet end and an ion outlet end and a gas flow within the ion separation region;
- and
- at least a portion of the set of electrodes having a set of direct current (DC) potentials applied thereto to generate a DC field in the ion separation region;
- and
- a gas recirculator including a first end opening to a location downstream of the ion separation region and a second end opening to a location upstream of the ion separation region, the gas recirculator having a pump for causing gas to flow:
- into the gas recirculator through one of the first end opening or the second end opening;
- and
- out the gas recirculator through the other of the first end opening or the second end opening;
- and
- wherein the DC field acts on ions in a direction substantially different to the direction of gas flow, such that ions are separated within the ion separation region in axial locations according to ion mobility.
A method for separating ions according to their ion mobilities, comprising:
- introducing ions to an inlet end of a mobility separation cell operating at sub-atmospheric pressure, the mobility separation cell having a plurality of electrodes defining an ion separation region;
- generating a DC field within an ion separation region by applying a set of DC potentials to at least some of the plurality of electrodes, wherein the DC field acts on ions in a direction substantially different to the direction of gas flow;
- and
- establishing a gas flow within the ion separation region, such that ions are separated within the ion separation region in axial locations determined by ion mobility, wherein the has flow is at least partially supplied by a gas recirculator having a first end located downstream of the ion separation region and a second end located upstream of the ion separation region.
Dependencies are inferred from the claim text.