Abstract: A mass spectrometry method comprises: (a) introducing ions and gas into a first electrode section of an ion transport apparatus along an axis, the ion transport apparatus further comprising a second electrode section including: a plurality of stacked, mutually parallel ring or plate electrodes; and an ion outlet aperture configured to receive the ions from the second electrode section and to transfer the ions to the vacuum chamber; (b) providing only non-oscillatory voltages to electrodes of the first electrode section of the ion transport apparatus that divert motion of the ions away from that axis and towards an entrance aperture of the second electrode section; (c) transporting the ions through the second electrode section to and through the ion outlet aperture to the vacuum chamber; and (d) removing a major portion of the gas through an exhaust port that is offset from the ion outlet aperture.

Abstract: A method of reducing fragmentation of ions generated from a sample during transport of the ions through an ion transport apparatus that comprises an ion funnel portion, comprises: applying a selected DC potential difference between an outlet end of the ion transport apparatus and an exit ion lens that is disposed adjacent to the outlet end, wherein a sign of the selected DC potential difference is chosen so as to accelerate the ions from the outlet end of the ion transport apparatus towards and through the exit ion lens.

Abstract: A mass spectrometry method comprises: (1) introducing ions and gas into an first electrode section of an ion transport apparatus through a slot of an ion transfer tube, the ion tunnel section comprising a first longitudinal axis that is contained within a slot plane of the ion transfer tube, the first longitudinal axis not intersecting an outlet of the ion transfer tube, wherein the apparatus further comprises: (a) a second electrode section configured to receive the ions from the first electrode section and comprising a second longitudinal axis that is not coincident with the first longitudinal axis; and (b) an ion outlet aperture; (2) providing voltages to electrodes of the ion transport apparatus that urge the ions to migrate towards the first longitudinal axis within the first electrode section; and (3) exhausting gas through a port that is offset from the ion outlet aperture.

Abstract: A method of reducing fragmentation of ions generated from a sample during transport of the ions through an ion transport apparatus that comprises an ion funnel portion, comprises: applying a selected DC potential difference between an outlet end of the ion transport apparatus and an exit ion lens that is disposed adjacent to the outlet end, wherein a sign of the selected DC potential difference is chosen so as to accelerate the ions from the outlet end of the ion transport apparatus towards and through the exit ion lens.

Abstract: An ion transport system comprises: (I) an ion transfer tube extending between an atmospheric-pressure ionization chamber and a partially evacuated chamber; and (II) an ion funnel within the chamber comprising: (1) an exit electrode that has an exit aperture configured to deliver the gas and charged particles to a high-vacuum chamber; and (2) a funnel portion comprising a plurality of plate electrodes configured as a stack, each electrode comprising a respective aperture, wherein an aperture diameter of each of the plurality of electrodes is greater than or equal to three times an inter-electrode pitch and wherein no DC electrical potential gradient is applied between the exit electrode and an adjacent one of the plurality of plate electrodes.