System and method for collisional activation of charged particles
AssigneeBattelle Memorial Institute
InventorsYehia M. Ibrahim, Mikhail E. Belov, David C. Prior
Life of this patent
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Abstract
A collision cell is disclosed that provides ion activation in various selective modes. Ion activation is performed inside selected segments of a segmented quadrupole that provides maximum optimum capture and collection of fragmentation products. The invention provides collisional cooling of precursor ions as well as product fragments and further allows effective transmission of ions through a high pressure interface into a coupled mass analysis instrument.
Claims26
An IMS-TOF-MS system, characterized by:
- a collision cell comprising an ion channel that defines an axis traversed by precursor ions in a buffer gas at a pressure greater than 20 mTorr, said collision cell includes a substantially orthogonal RF-focusing field and a locally increased axial DC-field centered within a preselected portion along said axis inside said collision cell that in operation yields a plurality of structure-identifying fragment ions inside said ion channel.
A method for enhanced fragmentation of ions, characterized by the steps of:
- applying an axial DC-field and a substantially orthogonal RF-focusing field along an axis defined through an ion channel of a collision cell;
- flowing a plurality of precursor ions at a pressure greater than 20 mTorr through said ion channel filled with a buffer gas;
- and
- fragmenting said precursor ions by collision with said buffer gas in said RF-focusing field, generating a plurality of structure-identifying fragment ions inside said ion channel.
A method for enhanced dissociation of precursor ions, characterized by the steps of:
- applying an axial DC-electric field generating an axial DC displacement gradient along a center longitudinal axis of a segmented N-pole device that accelerates a beam of charged precursor ions introduced inside said segmented N-pole device axially along said center longitudinal axis in said axial DC-electric field;
- activating said precursor ions by applying a DC-displacement field, radially displacing same from along said center longitudinal axis;
- and
- fragmenting said precursor ions by collision with neutral gas molecules in a stream of gas producing ion fragments thereof.
Dependencies are inferred from the claim text.