A sampling period of an A/D converter is set in accordance with an ion pulse ejection operation of a collision cell of an accumulation type. Start timing of the sampling period is changed in accordance with a selected m/z of a second mass analysis unit. In addition, end timing of the sampling period may be changed in accordance with the selected m/z of the second mass analysis unit. In place of the sampling period, a data cut-out period may be changed.

The present disclosure relates to methods of identifying components present in intact lipoprotein particles. Methods provided include single particle mass spectrometry, such as charge detection mass spectrometry (CDMS). Distinct subtypes and subpopulations that exist within lipoprotein density classes are determined based on simultaneously measured m/z and charge of ionized lipoprotein particles.

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 example system includes an ion detector and a signal processing apparatus in communication with the ion detector. The ion detector is arranged to detect ions during operation of the system and to generate a signal pulse in response to the detection of an ion. The signal pulse has a peak amplitude related to at least one operational parameter of the system. The signal processing apparatus is configured to analyze signal pulses from the ion detector and determine information about the detected ions during operation of the system based on the signal pulses. The signal processing apparatus includes a discriminator circuit. The signal processing apparatus is programmed to vary a threshold of the discriminator circuit based on the at least one operational parameter of the system during operation of the system.

An electrostatic linear ion trap (ELIT) array includes a plurality of ion mirrors and a plurality of elongated charge detection cylinders each defining an axial passageway centrally therethrough, the ion mirrors and the charge detection cylinders arranged relative to one another such that each charge detection cylinder is positioned between a different respective pair of the ion mirrors with the respective axial passageways of each coaxial with one another, wherein the axial passageways of the ELITs are not coaxial with one another, means for selectively directing at least one ion into each of the plurality of ELITs, and means for controlling each of the ion mirrors in a manner which causes the at least one ion in at least two of the ELITs to become trapped therein and to simultaneously oscillate back and forth between the respective ion mirrors each time passing through the respective charge detection cylinder.

In one aspect, a curtain and orifice plate assembly for use in a mass spectrometry system is disclosed, which comprises a curtain plate including a first printed circuit board (PCB) having an aperture configured for receiving ions generated by an ion source of the mass spectrometry system and at least one gas-flow channel, where said first PCB has at least one metal coating disposed on at least a portion thereof. The assembly further includes an orifice plate coupled to the curtain plate, which includes a PCB providing an orifice that is substantially aligned with the aperture of the curtain plate so that the ions entering the assembly via said aperture of the curtain plate can exit the assembly via said orifice of the orifice plate, where the second PCB has at least one metal coating disposed on at least a portion thereof.

In one aspect, a curtain and orifice plate assembly for use in a mass spectrometry system is disclosed, which comprises a curtain plate including a first printed circuit board (PCB) having an aperture configured for receiving ions generated by an ion source of the mass spectrometry system and at least one gas-flow channel, where said first PCB has at least one metal coating disposed on at least a portion thereof. The assembly further includes an orifice plate coupled to the curtain plate, which includes a PCB providing an orifice that is substantially aligned with the aperture of the curtain plate so that the ions entering the assembly via said aperture of the curtain plate can exit the assembly via said orifice of the orifice plate, where the second PCB has at least one metal coating disposed on at least a portion thereof.

A method of ion detection comprises: (a) setting electrical potentials of a dynode and a scintillator electrode of a Daly detector and of a focusing lens disposed at an ion inlet of the Daly detector so as to detect negatively charged ions received from a mass analyzer or mass filter; (b) transferring the negatively charged ions from the mass analyzer or mass filter to the Daly detector through the lens and detecting said negatively charged ions by a photodetector of the Daly detector; (c) setting electrical potentials of the dynode, the scintillator electrode and the focusing lens of the Daly detector so as to detect positively charged ions received from the mass analyzer or mass filter; and (d) transferring the positively charged ions from the mass analyzer or mass filter to the Daly detector through the lens and detecting said positively charged ions by the photodetector.

A signal processing assembly for a detector includes a signal amplifier, a control unit, and an offset control module. The signal amplifier is configured to receive an input signal from the detector assembly and to provide an output signal. The control unit is configured to compare a first data point from the output signal with a signal range, and to generate an input bias control signal based upon the comparison. The offset control module is coupled with the control unit and configured to receive the input bias control signal. The offset control module includes a power supply operatively coupled with an input of the signal amplifier, and the offset control module is configured to generate and apply an adaptive input offset signal at the input of the signal amplifier based upon the input bias control signal.

A method of mass spectrometry is disclosed comprising: performing a plurality of cycles of operation during a single experimental run, wherein each cycle comprises: mass selectively transmitting precursor ions of a single mass, or range of masses, through or out of a mass separator or mass filter at any given time, wherein the mass separator or mass filter is operated such that the single mass or range of masses transmitted therefrom is varied with time; and mass analysing ions.