A charge detection mass spectrometer (CDMS) includes an electrostatic linear ion trap (ELIT), a processor, and a memory having instructions stored therein executable by the processor to (a) control the ELIT to trap an ion, (b) collect ion measurement information as the trapped ion oscillates back and forth through the ELIT, the ion measurement information including charge induced by the ion on a charge detector of the ELIT during each pass of the ion through the ELIT and timing of the induced charges relative to one another, (c) process the ion measurement information in the time-domain for each of a plurality of sequential time windows of the ion measurement information to determine a charge magnitude of the ion during each time window, and (d) determine the magnitude of charge of the trapped ion based on the charge magnitudes of each of the time windows.

A charge filter instrument includes a field-free drift region, a plurality of charge detection cylinders in the drift region through which ions drifting axially therethrough pass, a plurality of charge sensitive amplifiers each coupled to at least one charge detection cylinder and configured to produce a charge detection signal corresponding to a charge of one or more of ions passing therethrough, a single inlet, single outlet charge deflector or a single inlet, multiple outlet charge steering device coupled to the outlet end of the drift region, means for determining charge magnitudes or charge states of ions drifting axially through the drift region based on the charge detection signals, and means for controlling the charge deflector or the charge steering device to pass through the single outlet or through a specified one of the multiple outlets only ions having a specified charge magnitude or charge state.

Systems and methods are provided for the analysis of single particles with inductively coupled plasma-time of flight mass spectrometry. An ion compression device is operated in combination with an image current detector to improve a duty cycle of particle analysis. The image current detection device is used to determine a start time and an end time of a separate ion cloud which is derived from a single particle. The ion compression device stores and compresses each ion cloud based on instructions from the image current detector. The duty cycle of the particle analysis can be improved up to nearly 100%. The ion compression device is additionally operated with an ion filtration device to achieve a lower detection limit and a higher signal-to-noise ratio.

A mass spectrometer may have an ion source region including an ion generator configured to generate ions from a sample, an ion detector configured to detect ions and produce corresponding ion detection signals, an electric field-free drift region disposed between the ion source region and the ion detector through which the generated ions drift axially toward the ion detector, a plurality of spaced-apart charge detection cylinders disposed in the drift region and through which the ions drifting axially through the drift region pass, and a plurality of charge amplifiers each coupled to a different one of the plurality of charge detection cylinders and each configured to produce a charge detection signal corresponding to a magnitude of charge of one or more of the generated ions passing through a respective one of the plurality of charge detection cylinders.

A method for determining a compensation factor parameter, c, for controlling an amount of ions ionised that are injected from an ion storage unit into mass analyser, where c is an adjustment factor that is applied to optimized injection times that are based on an optimized visible charge of a reference sample, the method comprising: detecting at least one mass spectrum for at least one amount of injected ions; determining from the at least one detected mass spectrum, a slope, s(sample), of a linear correlation of a relative m/z shift with visible total charge Q.sub.v of detected mass spectra; determining the compensation factor c as c=s(reference)/s(sample) where s(reference) is the slope of a linear correlation between reference-sample relative m/z shift values and reference-sample visible charge values determined from a plurality of mass spectra detected from a plurality of respective pre-selected amounts of a clean reference sample.

A CDMS may include an ELIT having a charge detection cylinder (CD), a charge generator for generating a high frequency charge (HFC), a charge sensitive preamplifier (CP) having an input coupled to the CD and an output configured to produce a charge detection signal (CHD) in response to a charge induced on the CD, and a processor configured to (a) control the charge generator to induce an HFC on the CD, (b) control operation of the ELIT to cause a trapped ion to oscillate back and forth through the CD each time inducing a charge thereon, and (c) process CHD to (i) determine a gain factor as a function of the HFC induced on the CD, and (ii) modify a magnitude of the portion of CHD resulting from the charge induced on the CD by the trapped ion passing therethrough as a function of the gain factor.

A method for correcting mass spectral m/z values comprises: detecting mass spectra for different amounts of sample ions within an ion trapping mass analyzer; evaluating an observable difference of relative m/z shift from the detected mass spectra of at least two of the different amounts of ions induced by space charge; evaluating a visible total charge Q.sub.v and/or the difference of a visible total charge Q.sub.v from the detected mass spectra; determining, from the evaluated observable differences of relative m/z shift and the evaluated visible total charges Q.sub.v and/or differences of the visible total charge Q.sub.v, a slope of a linear correlation between relative m/z shift and visible total charge Q.sub.v; determining a relative m/z shift of sample ions detected in a mass spectrum by multiplying visible total charge Q.sub.v with the determined slope; and correcting the m/z values in the mass spectrum using its determined relative m/z shift.

The present invention comprises novel methods of continuously monitoring the performance of an atmospheric pressure ionization (API) system. The methods of the invention allow for improved quality monitoring of the processes that leads to the formation of ions at atmospheric pressure. The methods of the invention further allow for continuously monitoring for the quality of the ion formation process in API without the addition of extraneous material (such as labelled compounds or control known compounds) to the system being monitored.

A charge detection mass spectrometer may include an electrostatic linear ion trap (ELIT) or orbitrap, a source of ions to supply ions to the ELIT or orbitrap, a processor operatively coupled to the ELIT or orbitrap, a display monitor coupled to the processor, and a memory having instructions stored therein executable by the processor to produce a control graphic user interface (GUI) on the display monitor, the control GUI including at least one selectable GUI element for at least one corresponding operating parameter of the ELIT or orbitrap, receive a first user command, via user interaction with the control GUI, corresponding to selection of the at least one selectable GUI element, and control the ELIT or orbitrap to control the at least one corresponding operating parameter of the ELIT or orbitrap in response to receipt of, and based on, the first user command.

A system 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 orbitrap in which a rotating and oscillating ion induces charges on inner and outer electrode halves of the orbitrap, and wherein charge detection circuitry is configured to detect the charges induced on each of the inner electrode halves and on each of the outer electrode halves, and to combine the detected charges for each oscillation to produce a measured ion charge signal.