Abstract: A mass spectrometry method comprises: receiving a stream of ions at an inlet end of an ion transport device; accumulating a first portion of the ion stream at a first electrical potential well at a first position within the ion transport device between the inlet and outlet ends; creating a generally descending potential profile within the ion transport apparatus between a second position and the outlet end and, simultaneously, creating a second potential well at a third position within the ion transport apparatus, the second position disposed between the first position and the inlet end, the third position disposed between the second position and the inlet end; and transporting the accumulated first portion of the ion stream from the first position to the outlet end under the impetus of the generally descending potential profile and, simultaneously, accumulating a second portion of the ion stream at the second potential well.

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.

Abstract: A mass spectrometry method comprises: receiving a stream of ions at an inlet end of an ion transport device; accumulating a first portion of the ion stream at a first electrical potential well at a first position within the ion transport device between the inlet and outlet ends; creating a generally descending potential profile within the ion transport apparatus between a second position and the outlet end and, simultaneously, creating a second potential well at a third position within the ion transport apparatus, the second position disposed between the first position and the inlet end, the third position disposed between the second position and the inlet end; and transporting the accumulated first portion of the ion stream from the first position to the outlet end under the impetus of the generally descending potential profile and, simultaneously, accumulating a second portion of the ion stream at the second potential well.