The invention provides a trapped ion mobility separator (TIMS) and methods to operate it wherein an ion region of the TIMS, through which ions travel along an axis from an entrance to an exit, has an elongate cross-sectional profile perpendicular to the axis with a long dimension and a short dimension. First and second counteracting forces on the ions along the axis are provided, wherein at least one of the first and second forces has an effect on the ions that is ion mobility dependent, and wherein at least one of the first and second forces varies spatially along the axis such that ions are trapped and separated by ion mobility. Different embodiments provide the first and second forces using different combinations of gas flow and electric field potential, and employ various electrode structures that provide the system with different advantageous characteristics.

The invention provides a trapped ion mobility separator (TIMS) and methods to operate it wherein an ion region of the TIMS, through which ions travel along an axis from an entrance to an exit, has an elongate cross-sectional profile perpendicular to the axis with a long dimension and a short dimension. First and second counteracting forces on the ions along the axis are provided, wherein at least one of the first and second forces has an effect on the ions that is ion mobility dependent, and wherein at least one of the first and second forces varies spatially along the axis such that ions are trapped and separated by ion mobility. Different embodiments provide the first and second forces using different combinations of gas flow and electric field potential, and employ various electrode structures that provide the system with different advantageous characteristics.

In one aspect of the invention, an ion trap mass analyzer includes a variable- or multi-potential type ion guide (MPIG) assembly which has been pre-configured to produce a parabolic-type potential field. Each MPIG electrode has a resistive coating of designed characteristics. In one example the coating varies in thickness along the length of an underlying uniform substrate. The MPIG assembly can be a single MPIG electrode or an array of a plurality of MPIG electrodes. An array can facilitate delocalization for improved performance. This chemical modification of a uniform underlying substrate promotes cheaper and flexible instruments. The modified MPIG electrodes also allow miniaturization (e.g. micro and perhaps even nano-scale), which allows miniaturization of the instrument in which the single or plural modified MPIG electrode(s) are placed. This promotes portability and field use instead of limitation to laboratory settings.

An instrument for analyzing ions may include an ion source to generate ions, at least one ion processing instrument to process the generated ions by one or both of filtering the ions according to a molecular characteristic and dissociating the ions, and an electrostatic linear ion trap (ELIT) to receive and trap ions exiting the at least one ion processing instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that trapped ions oscillate back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ions traversing the charge detection cylinder and total time spent by the trapped ions traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

An ion mobility separator 4 and a method of separating ions according to their ion mobility are disclosed. An RF ion guide is provided having a plurality of electrodes that are arranged to form an ion guiding path that extends in a closed loop. RF voltages are supplied to at least some of the electrodes in order to confine ions within said ion guiding path. A DC voltage gradient is maintained along at least a portion of a longitudinal axis of the ion guide, wherein the voltage gradient urges ions to undergo one or more cycles around the ion guide and thus causes the ions to separate according to their ion mobility as the ions pass along the ion guide. The closed loop ion guide enables the resolution of the ion mobility separator to be increased without necessitating a large device, since the drift length through the device can be increased by causing the ions to undergo multiple cycles around the device.

An ion transfer device of a mass spectrometry system that includes a first ion guide such that the first ion guide traps the ions in a first potential well formed by a first potential gradient and a first potential barrier within the first ion guide, and a second ion guide that receives the ions from the first ion guide if the first potential barrier is reduced such that during a time period when the ions travel toward one end of the second ion guide, a second potential barrier is gradually formed by increasing a third voltage applied to a third electrode at the one end of the second ion guide, the second potential barrier preventing the ions from exiting the second ion guide or from colliding with the third electrode.

A mass spectrometry system including an ion transfer device that receives the ions and produces a plurality of ion packets, such that the ion transfer device receives the ions from an inlet of the ion transfer device, forms a first ion packet, and delivers the first ion packet to an outlet, such that during the time when the ion transfer device delivers the first ion packet via the outlet of the ion transfer device, the ion transfer device simultaneously receives the ions from the inlet to form a second ion packet inside the ion transfer device from the received ions, the second ion packet is separate from the first ion packet, and such that the ion transfer device delivers each of the plurality of ion packets to the outlet of the ion transfer device at a frequency in a range from 1 Hz to 1000 Hz.

An instrument for analyzing ions includes at least one separation instrument configured to produce a flow of a sample solution in which molecules in the sample solution are separated as a function of at least one molecular characteristic, an ion source to generate ions from the sample solution flow, and an electrostatic linear ion trap (ELIT) to receive and trap ions exiting the at least one ion processing instrument. The ELIT is configured such that trapped ions oscillate back and forth through a charge detection cylinder between first and second ion mirrors at opposite ends of the cylinder with a duty cycle, corresponding to a ratio of time spent by the trapped ions traversing the charge detection cylinder and total time spent by the trapped ions traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

A mass spectrometry system that includes an ion source that produces ions, an ion transfer device, and a mass analyzer. The ion transfer device includes a first ion transfer device that receives ions from an inlet and transfers ions to an outlet, and includes a plurality of first plate electrodes that are stacked, each plate electrode having a hole with a same diameter, and separated by a first inter-electrode spacing such that the hole diameter is between 1 to 100 times the first inter-electrode spacing; a second ion transfer device receives and transfers the ions, and includes a plurality of second plate electrodes with holes having a same diameter, separated by a second inter-electrode spacing such that the hole diameter is between 3 to 100 times the second inter-electrode spacing; and a third ion transfer device includes a plurality of third plate electrodes with holes having a plurality of diameters.

A mass spectrometry system that includes an ion source that produces ions, an ion transfer device, and a mass analyzer. The ion transfer device includes a first ion transfer device that receives ions from an inlet and transfers ions to an outlet, and includes a plurality of first plate electrodes that are stacked, each plate electrode having a hole with a same diameter, and separated by a first inter-electrode spacing such that the hole diameter is between 1 to 100 times the first inter-electrode spacing; a second ion transfer device receives and transfers the ions, and includes a plurality of second plate electrodes with holes having a same diameter, separated by a second inter-electrode spacing such that the hole diameter is between 3 to 100 times the second inter-electrode spacing; and a third ion transfer device includes a plurality of third plate electrodes with holes having a plurality of diameters.