Abstract: 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.

Abstract: Disclosed herein are systems and methods for sorting ions including a group of multipole electrodes configured to form an ion trap, and an ion guide adjacent to, and operably coupled to the group of multipole electrodes. Using a radio frequency (RF) or Direct Current (CD) power supply device the system can apply an RF voltage to the group of multipole electrodes thereby creating a pseudo-potential barrier. A DC gradient voltage may then be applied creating an axial field in opposition to the pseudo-potential barrier. As the DC voltage is raised and/or the RF voltage is lowered, one or more ions will be eluted through the barrier.

Abstract: An ion source includes an electron generator, an ionization chamber, and a magnetic field. The electron generator is configured to produce electrons. The ionization chamber has an electron entrance aperture through a first wall, an ion exit aperture through a second wall, and an axis. The ionization chamber is configured to produce ions. The magnetic field is arranged to confine electrons in a beam directed through the electron entrance aperture, in a direction within 45 degrees of parallel to the axis, and towards a location displaced from the ion exit aperture.

Abstract: Adjusting compensation voltage (CV) parameters of an ion mobility device is described. In one instance, the CV parameters are adjusted to reflect a different CV range, a number of CV steps, or a CV step size to increase throughput of a mass spectrometer.

Abstract: A method comprises: obtaining, from a series of mass spectra including a most recent mass spectrum and a plurality of previously-acquired mass spectra, an elution profile comprising a plurality of detection points each representing intensity of ions accumulated over an accumulation time and detected by a detector as a function of time; classifying, based on a subset of detection points included in the plurality of detection points, a current signal state of the elution profile; and setting, for a next acquisition of a mass spectrum, the accumulation time based on the classified current signal state of the elution profile.

Abstract: An ion mobility analyser is disclosed having a gas flow directed along the ion travel axis and a set of electrodes to which DC voltages are applied to establish a DC field. The opposing forces of the gas flow and DC field cause ions to be trapped within a separation region in axial regions determined by their ion mobilities. A gas recirculator, having inlet and outlet ends respectively located downstream and upstream of the separation region, supplies at least fifty percent of the gas flow within the separation region, thereby reducing vacuum pumping requirements.

Abstract: Packed-tip electrospray ionization (ESI) emitters for mass spectrometry are described. In one aspect an ESI emitter stores a first type of particle. A liquid chromatography (LC) column is coupled with the emitter via a junction. The LC column stores a different type of particle than the ESI emitter to facilitate better chromatographic and ESI performance.

Abstract: An ion separation apparatus comprises: (a) first and second ion carpets, each comprising: a substrate having first and second faces; and a set of electrodes disposed on or beneath the first face, wherein a configuration of a first plurality of the set of electrodes defines at least one group of circle sectors; (b) an ion exit aperture passing through one ion carpet; and (c) one or more power supplies configured to provide radio frequency voltages to a first subset of the electrodes of each ion carpet, to provide electrical potential differences across electrodes of the first subset of electrodes of each ion carpet, and to provide time-varying voltages to the first plurality of electrodes of each ion carpet that migrate through the sectors as a traveling wave, wherein the ion carpets are disposed parallel to one another with a gap therebetween, the first faces facing one another across the gap.

Abstract: A mass spectrometer support apparatus includes a peak shape logic to determine one or more peak shapes using a calibration mass spectrum and known peak locations; and a tuning logic to adjust instrument parameters to achieve a selected peak width. A method for tuning a quadrupole-based mass spectrometer includes determining one or more peak shapes using a calibration mass spectrum and known peak locations; and adjusting instrument parameters to achieve a selected peak width.

Abstract: Determining a level of a liquid in a container is described. In one aspect, a container includes a calibrant liquid used for calibrating a mass spectrometer. A conductive layer is placed to float upon the calibrant liquid, and a circuit board with electrodes is arranged around the container. A controller circuit then drives and measures various electrodes to first identify which two electrodes the level of the calibrant liquid is between, and then subsequently identify a more precise location for the level between the two electrodes.

Abstract: A method of performing mass spectrometry includes obtaining, based on a series of mass spectra of detected ions derived from components eluting from a chromatography column, a plurality of extracted ion chromatograms (XICs), each XIC comprising a plurality of detection points representing detected intensity for a distinct selected m/z as a function of time; detecting, based on the series of mass spectra, precursor ions of each distinct selected m/z of the plurality of XICs; and determining, for each XIC based on a set of detection points of the XIC, a predicted next detection point to be obtained based on a next mass spectrum to be acquired.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole. A controller circuit can determine that the actual amplitude of the RF signal differs than the expected amplitude and, in response, identify current and past environmental and performance parameters to adjust the amplitude.

Abstract: A Liquid Chromatography Mass Spectrometry system comprises: a chromatograph; a mass spectrometer configured to ionize separated fractions of a sample received from the chromatograph; and a programmable processor operable to repeatedly execute the steps of: (i) causing the mass spectrometer to perform a data-independent analysis of the precursor ion species using a mass analyzer of the mass spectrometer; (ii) calculating one or more degree-of-matching scores that relate to detection of an internal standard; and (iii) if each of the degree-of-matching scores meets a respective degree-of-matching condition, performing a quantitative tandem mass spectrometric analyses of both the internal standard and the analyte; the programmable processor further operable to calculate a quantity of the analyte in the sample by comparison between intensities of one or more mass spectral signals generated by the quantitative tandem mass spectrometric analyses of the analyte and the internal standard.

Abstract: A method of performing mass spectrometry includes accessing a series of mass spectra of detected ions derived from components eluting from a chromatography column; obtaining, based on the series of mass spectra, an elution profile including a plurality of detection points representing intensity of at least a set of the detected ions as a function of time; and determining, based on a set of detection points included in the plurality of detection points, a predicted next detection point of the elution profile to be obtained based on a next mass spectrum to be acquired subsequent to acquisition of the series of mass spectra.

Abstract: A method for preparing a protein-containing sample for analysis by mass spectrometry includes introducing the sample into a reaction vessel. The reaction vessel contains a reagent mixture including pre-measured quantities of an immobilized proteolytic enzyme, a reducing agent and an alkylating agent. The contents of the reaction vessel are activated by heating or by sonication.

Abstract: An electrospray ionization system used in mass spectrometry provides for improved current measurement. The system includes a fluid union, a fluid column coupled with a first port of the fluid union, a power source coupled with the fluid union and configured to apply a voltage potential to the fluid union, and an electrospray emitter coupled with a second port of the fluid union. The power source is coupled with the first port and configured to apply the voltage potential to the first port to restrict current leakage from the fluid union. The current sensing circuit is configured to determine an electrical current flow between the power source and the at least one of the fluid union and the first port.

Abstract: Real-time search (RTS) for mass spectrometry is described. In one aspect, a mass spectrometer can identify a candidate peptide for a product ion spectrum by searching a mass spectral database. While executing the search of the mass spectral database, the elapsed search time can be monitored. If the elapsed search time of the identification of the candidate peptide is completed before reaching a maximum value, then the mass spectrometer can perform further actions.

Abstract: A method of operating a mass spectrometer that allows for high-speed operation is disclosed. The method consists in separating the various steps needed to produce a mass spectrum into three or more conceptual stages in a pipeline, such that the instrument is performing steps to process more than two precursor-ion species simultaneously. In general, the number of stages in the pipeline should at least one more and, preferably, at least two more than the number of buffering storage devices in the instrument. The presently-taught methods and apparatus allow for nearly 100% duty cycle of ion accumulation for precursors of interest.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: Methods are described for the automatic determination and correction of retention time shift of a MS data set relative to a control data set, to correct for retention time drifts endemic to targeted LCMS analyses. In an embodiment, a 2D grid of periodic MS spectra versus time is collected for a control experiment, and RT windows are determined with an additional set of unscheduled mass spectral analyses. During successive experiments, spectra from periodic MS scans are used to determine the correspondence between the current time and the time in the control experiment. The active set of MSn scans to be acquired by the instrument is then determined as the scans with adjusted retention time windows that bracket the corrected retention time.