Patent classifications
H01J49/0072
Systems and methods using a gas mixture to select ions
Certain configurations described herein are directed to mass spectrometer systems that can use a gas mixture to select and/or detect ions. In some instances, the gas mixture can be used in both a collision mode and in a reaction mode to provide improved detection limits using the same gas mixture.
Swath® to extend dynamic range
Systems and methods are disclosed for determining if the dynamic range of quantitation in mass spectrometry can be extended. A DIA method is performed on a sample for a compound of interest at each acquisition time of a plurality of acquisition times. A plurality of product ion spectra are produced for each window of two or more precursor ion mass selection windows. A known product ion of the compound of interest is selected. Two or more XICs are calculated from two or more different precursor ion windows for the known product ion. A ratio of one XIC of the two or more XICs to at least one other XIC of the two or more XICs is calculated. If the ratio is above a threshold, the XIC is used in the quantitation. If not, two or more XICs can be combined into a single XIC that is used for the quantitation.
Methods and apparatus for ion fragmentation in a mass spectrometer
A method of fragmenting ions comprises: injecting first ions of a first charge into an ion trap that includes an elongate multipole electrode assembly defining an elongate ion channel; radially confining the first ions within the ion channel by applying an RF pseudopotential to the electrode assembly and axially confining said ions to a first volume within the ion channel by applying a first potential well to the ion channel; injecting second ions of a second charge opposite to the first charge into the ion trap; axially confining the second ions to a second volume within the ion channel by applying a second potential well to the ion channel, the first potential well being within the second potential well; cooling the first and second ions in the ion trap; and allowing the ions to interact such that the first ions and/or second ions are fragmented to produce product ions.
Apparatus and method for glycopeptide analysis
A system and method is described for characterizing glycopeptides which includes a first quadrupole mass filter, a multipole rod set of an ion guide, a lens electrode, an ExD device and a mass analyzer. The multipole rod set is adapted to receive a radial radio frequency (RF) trapping voltage and a radial dipole direct current (DC) voltage The lens electrode is adapted to receive an axial trapping alternating current (AC) voltage and a DC voltage. The ExD device performs electron capture dissociation or electron transfer dissociation, the ExD device being positioned so that an entrance of the ExD device is disposed on the other side of the lens electrode opposite the multipole rod set. The mass analyzer is positioned at an exit of the ExD device for receiving ions from the ExD device.
Apparatus for delivering reagent ions to a mass spectrometer
Disclosed herein is an apparatus for supplying reagent ions, for example ETD or PTR reagent ions, to a mass spectrometer. The apparatus includes a reagent material reservoir, coupled to a carrier gas supply, which delivers an entrained reagent vapor flow to an inlet of a mixing junction through a first flow restrictor. A control gas flow of carrier gas is delivered to another inlet of the mixing junction via a variable pressure regulator and a second flow restrictor. The outlet of the mixing junction is coupled via a third flow restrictor and a reagent transfer junction to an inlet of an ionizer, such as a glow-discharge ionizer. By dynamic adjustment of the output pressure of the variable pressure regulator, the flow rate of reagent vapor may be controlled over a broad range, even for reagent materials of relatively high volatility.
METHODS AND APPARATUS FOR HIGH SPEED MASS SPECTROMETRY
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.
FAST COOLING OF ION MOTION IN A LONG CHAIN USING LOCAL MODES
Aspects of the present disclosure describe techniques for fast cooling of ion motion in a long chain using local motional modes. For example, a method is described for cooling down ions in a chain of ions that includes performing a cooling down sequence in which phonons are removed from the ions in the chain of ions by exciting and de-exciting local motional modes associated with individual ions, wherein sideband transitions that are part of the cooling down sequence are driven faster for the local motional modes than for collective motional modes for the same chain of ions; and completing the cooling down sequence when the local motional modes reach a ground state. A corresponding system and computer-readable storage medium for fast cooling of ion motion in a long chain using local motional modes are also described.
MASS SPECTROMETRY METHOD AND MASS SPECTROMETER
A mass spectrometer 1, which is for generating a product ion from a precursor ion derived from a sample component having a hydrocarbon chain to analyze a mass, includes a reaction chamber 2 into which the precursor ion is introduced, radical generating units 51, 52, and 53 that generate a radical having an oxidizing ability or/and a radical other than a hydrogen radical having a reducing ability, a radical irradiation unit 54 that irradiates the inside of the reaction chamber 2 with the generated radical, a separation detection unit 3 that separates and detects the product ion generated from the precursor ion by a reaction with the radical according to a mass-to-charge ratio, and a structure estimation unit 14 that estimates the structure of the sample component based on the mass-to-charge ratio of the detected product ions and the information on the structure or the structure candidate.
INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) WITH IMPROVED SIGNAL-TO-NOISE AND SIGNAL-TO-BACKGROUND RATIOS
In an inductively coupled plasma-mass spectrometry (ICP-MS) system, ions are transmitted into a collision/reaction cell. A DC potential is applied at an exit of the cell at a first magnitude to generate a DC potential barrier effective to prevent the ions from exiting the cell. The DC potential barrier is maintained during a confinement period to perform an interaction. After the confinement period, analyte ions or product ions are transmitted to a mass spectrometer by switching the exit DC potential to a second magnitude effective to allow the analyte ions or product ions to pass through the cell exit as a pulse. The analyte ions or product ions are then counted during a measurement period. The interaction may be ion-molecule reactions or ion-molecule collisions.
METHODS AND APPARATUS FOR ION FRAGMENTATION IN A MASS SPECTROMETER
A mass spectrometer includes a controller operable to: transfer first ions of a first charge into an ion trap; apply an RF pseudopotential that radially confines the first ions in an elongate ion channel of the trap; generate a first potential well that confines the first ions within a first volume; after a specified pre-cooling time, transfer second ions of a second, opposite charge into the trap; apply one or more additional DC potentials that generate a second potential well that confines the second ions within a second volume, the first potential well being within the second potential well; cause, after cooling the second ions, the first ions and the second ions to interact and generate product ions; and generate at least one third potential well that confines the product ions, that is adjacent to the second potential well and that has a same polarity as the first potential well.