In one aspect, a method of processing ions in a mass spectrometer is disclosed, which comprises trapping a plurality of ions having different mass-to-charge (m/z) ratios in a collision cell, releasing said ions from the collision cell in a descending order in m/z ratio, and receiving the ions in a mass analyzer having a plurality of rods to at least one of which an RF voltage is applied, where the RF voltage is varied from a first value to a lower second value as the released ions are received by the mass analyzer.

In one embodiment, a power source for providing high-voltage radio-frequency (RF) energy to an instrument such as a mass spectrometer includes an RF power amplifier having an output, an oscillating RF signal generator configured to provide first and second RF signals respectively oscillating at first and second frequencies to the RF power amplifier, and a step-up circuit for magnifying the RF power amplifier output. The step-up circuit includes an LC resonator network tuned to the first and second frequencies, and an output for providing the magnified voltage to a rod assembly of the mass spectrometer.

A mass selective ion trapping device includes a linear ion trap and a RF control circuitry. The ion trap includes a plurality of trap electrodes configured for generating a quadrupolar trapping field in a trap interior and for mass selective ejection of ions from the trap interior. The RF control circuitry is configured to apply a balanced AC voltage to the trap electrodes during a first period of time such that an AC voltage applied to a first pair of trap electrodes is of the same magnitude and of opposite sign to an AC voltage applied to a second pair of trap electrodes; apply unbalanced RF voltage to the second pair of trap electrodes during a second period of time; ramp the balanced AC voltage down and the unbalanced RF voltage up during a transition period; and eject ions from the linear ion trap after the second period of time.

A mass spectrometry method comprising steps of generating an ion beam from an ion source; directing the ion beam into a collision cell; introducing into the collision cell through a gas inlet on the collision cell a charge-neutral analyte gas or reaction gas; ionizing the analyte gas or reaction gas in the collision cell by means of collisions between the analyte gas or reaction gas and the ion beam; transmitting ions from the ionized analyte gas or reaction gas from the collision cell into a mass analyzer; and mass analyzing the transmitted ions of the ionized analyte or reaction gas. The methods can be applied in isotope ratio mass spectrometry to determine the isotope abundance or isotope ratio of a reaction gas used in mass shift reactions between the gas and sample ions, to determine a corrected isotope abundance or ratio of the sample ions.

A dissociation device fragments a precursor ion, producing at least two different product ions with overlapping m/z values in the dissociation device. The dissociation device applies an AC voltage and a DC voltage creating a pseudopotential that traps ions below a threshold m/z including the at least two product ions. The dissociation device receives a charge reducing reagent that causes the trapped at least two product ions to be charge reduced until their m/z values increase above the threshold m/z set by the AC voltage. The increase in the m/z values of the at least two product ions decreases their overlap. The at least two product ions with increased m/z values are transmitted to another device for subsequent mass analysis by applying the DC voltage to the dissociation device relative to a DC voltage applied to the other device.

An ion-optical device comprising: a plurality of electrodes (2); a first AC voltage supply (6); and a transformer (4) having: a toroidal core (8); a primary winding (10) connected to the AC voltage supply (6) and passing through the aperture within the toroidal core (8); and at least one secondary winding (13,15) wound around the toroidal core 8 and electrically connected to multiple ones of said plurality of electrodes.

Devices and methods for surface-induced association are disclosed herein. According to one embodiment, a device for surface-induced dissociation (SID) includes a collision surface and a deflector configured to guide precursor ions from a pre-SID region to the collision surface. In some embodiments, an extractor extracts ions off the collision surface after collision with the collision surface. In some embodiments, an RF device can collect and/or transmit the extracted ions. In some embodiments, an ion funnel guides product ions resulting from collision with the collision surface to a post-SID region. Some aspects of the disclosure are directed to methods for surface-induced dissociation, which may in some embodiments include using of a split lens or an ion funnel.

A device for controlling trapped ions includes a first substrate. A second substrate is disposed over the first substrate. One or a plurality of first level ion traps is configured to trap ions in a space between the first substrate and the second substrate. One or a plurality of second level ion traps is configured to trap ions in a space above the second substrate. An opening in the second substrate is provided through which ions can be transferred between a first level ion trap and a second level ion trap.

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 ion trap (100) includes a first electrode pair (110) and a second electrode pair (130), each including a first conductive member (112) and a second conductive member (120) and facing each other so that the first conductive member (112) of the first electrode pair (110) is on a common plane with the second conductive member (120) of the second electrode pair (130) and so that the second conductive member (120) of the first electrode pair (110) is on a common plane with the first conductive member (112) of the second electrode pair (130), a gap (132) therebetween. A signal generator (210) generates a periodic signal (212) applied to the first conductive members (112). A phase shifter (216) generates a second periodic signal (218) that is 180 out of phase therewith applied to the second conductive members (120). Ions are trapped by a resulting electric field.