A charge detection mass spectrometer includes an ion trap configured to receive and store ions therein and to selectively release stored ions therefrom, and an electrostatic linear ion trap (ELIT) spaced apart from the ion trap, the ELIT including first and second ion mirrors and a charge detection cylinder positioned therebetween, and means for selectively controlling the ion trap to release at least some of the stored ions therefrom to travel toward and into the ELIT, and for controlling the first and second ion mirrors in a manner which traps in the ELIT a single one of the ions traveling therein and causes the trapped ion to oscillate back and forth between the first and second ion mirrors each time passing through and inducing a corresponding charge on the charge detection cylinder.

A mass spectrometer system comprises: (a) an ion source; (b) a mass filter or a time-of-flight (TOF) ion separator configured to receive a stream of first-generation ions from the ion source; (c) an ion storage device having an ion inlet configured to receive a stream of filtered ions comprising a plurality of ion species from the mass filter or TOF separator and to accumulate the plurality of ion species therein; (d) an ion mobility cell having an ion inlet configured to receive an accumulated batch of ion species from the ion storage device and an ion outlet configured to release, one at a time, the individual ion species therefrom; and (e) a mass analyzer configured to receive and mass analyze each first-generation ion species or each fragment ion species generated by fragmentation or other reaction of the various first-generation ion species.

A method for correcting mass spectral data obtained for a sample is described, where the mass spectral data is a time-of-flight mass spectral data. The method includes receiving mass spectral data obtained from a sample, the mass spectral data being indicative of an ion abundance. The method further includes applying a correction function to the mass spectral data based on the ion abundance indicated by the mass spectral data and on one or more trapping parameters associated with the mass spectral data. The correction function defines correction values for the mass spectral data for a range of ion abundances and for a range of trapping parameters.

An instrument for separating ions may include an ion source configured to generate ions from a sample, at least one ion separation instrument configured to separate the generated ions as a function of at least one molecular characteristic and an electrostatic linear ion trap (ELIT) positioned to receive ions exiting the at least one ion separation instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that an ion trapped therein oscillates 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 ion traversing the charge detection cylinder and total time spent by the trapped ion 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 trapping system is disclosed comprising an ion urging system for urging ions to spread out within an ion trapping region. Alternatively, the ion trapping system may deflect ions such that ions enter the ion trapping region at different locations. Alternatively, an ion deflector may be arranged upstream of, or at the entrance to, the ion trapping region, for deflecting ions such that ions enter the ion trapping region with different speeds so that the ions spread out within the ion trapping region.

A mass spectrometry method comprises: introducing a first packet of ions into an electrostatic trap mass analyzer through a set of electrostatic lenses, wherein, during the introducing of the first packet, either the lenses are operated in a first mode of operation or an injection voltage of a first pre-determined magnitude is applied to an electrode of the mass analyzer; mass analyzing the first ion packet using the mass analyzer; introducing a second packet of ions into the mass analyzer through the set of lenses, wherein, during the introducing of the second packet, either the lenses are operated in a second mode of operation or an injection voltage of a second pre-determined magnitude is applied to the electrode of the mass analyzer; and mass analyzing the second packet of ions using the electrostatic trap mass analyzer.

Disclosed herein are various methods and apparatus for performing charge detection mass spectrometry (CDMS). In particular, techniques are disclosed for monitoring a detector signal from a CDMS device to determine how many ions are present in the ion trap (10) of the CDMS device. For example, if no ions are present the measurement can then be terminated early. Similarly, if more than one ion is present, the measurement can be terminated early, or ions can be removed from the trap (10) until only a single ion remains. Techniques are also provided for increasing the probability of there being a single ion in the trap (10). A technique for attenuating an ion beam is also provided.

A linear ion trap includes at least two discrete trapping regions for processing ions, a RF electrical potential generator, a multi-output DC electrical potential generator, and a control unit. The RF electrical potential generator produces two RF waveforms each applied to a pair of pole electrodes of the linear ion trap forming a RF trapping field component to trap ions radially. The multi-output DC electrical potential generator produces multiple DC field components superimposed to the RF field component and distributed across the length of the linear ion trap to control ions axially. The control unit switches the DC electrical potentials and corresponding DC field components collectively forming a first trapping region populated with ions to alter ion potential energy from a first level to a second level, and enables a first ion processing step in at least one of the first and second levels.

An instrument for separating ions may include an ion source configured to generate ions from a sample, at least one ion separation instrument configured to separate the generated ions as a function of at least one molecular characteristic and an electrostatic linear ion trap (ELIT) positioned to receive ions exiting the at least one ion separation instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that an ion trapped therein oscillates 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 ion traversing the charge detection cylinder and total time spent by the trapped ion traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

A method of operating a quadrupole device is disclosed that comprises operating the quadrupole device in a first mode of operation, and operating the quadrupole device in a second mode of operation. Operating the quadrupole device in the first mode of operation comprises applying one or more first voltages to the quadrupole device such that the quadrupole device is operated in an initial stability region and such that at least some ions are stable within the quadrupole device. Operating the quadrupole device in the second mode of operation comprises applying one or more second voltages to the quadrupole device such that the quadrupole device is operated in a different stability region and such that at least some of the ions that were stable within the quadrupole device in the first mode of operation are stable within the quadrupole device in the second mode of operation.