Abstract: A method of mass spectrometry for analyzing a sample within a mass range of interest includes the steps: ionizing the sample to produce a plurality of precursor ions; performing an MS1 scan of the precursor ions comprising mass analyzing the precursor ions across the mass range of interest, to obtain an MS1 mass spectrum of the precursor ions; determining ion intensity values within the MS1 mass spectrum; selecting precursor mass segments within the mass range of interest, and for each precursor mass segment: fragmenting the precursor ions within that precursor mass segment; and performing an MS2 scan of the fragmented ions by: controlling an amount of fragmented ions for that precursor mass segment, based on an intensity value for that precursor mass segment derived from the MS1 spectrum; and mass analyzing the amount of fragmented ions.

Abstract: A method for determining an isotopic profile for a molecule is provided. The isotopic profile is indicative of an isotopic content for the molecule. The method comprises mass selecting ions of the molecule in a mass window, the mass window excluding a mass for a monoisotopic molecular ion and including a mass for at least one isotopic variant of the monoisotopic molecular ion. The method comprises fragmenting the mass selected ions into fragment ions, performing mass analysis on one or more of the fragment ions to produce a mass spectrum, and determining the isotopic profile for the molecule, the isotopic profile comprising at least one data value. Each data value is calculated for a fragment ion as a function of intensities of multiple peaks in the mass spectrum. A computer program is provided. A mass spectrometry system is provided. A method for identifying a sample is provided.

Abstract: An isotope ratio spectrometer is operated for measurement of a sample. First isotope ratios and first signal intensities are measured for a reference in the spectrometer, over a first measurement time period. A first relationship comprising a relationship between the first isotope ratios and the first signal intensities is determined. Sample isotope ratios and sample signal intensities are measured in the spectrometer, over a second measurement time period subsequent to the first measurement time period. Second isotope ratios and second signal intensities for a reference are measured in the spectrometer, over a third measurement time period subsequent to the second measurement time period. A second relationship comprising a relationship between the second isotope ratios and the second signal intensities is determined. A reference isotope ratio is estimated for a time X within the second measurement time period, based on the first relationship and the second relationship.

Abstract: 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 Qv and/or the difference of a visible total charge Qv from the detected mass spectra; determining, from the evaluated observable differences of relative m/z shift and the evaluated visible total charges Qv and/or differences of the visible total charge Qv, a slope of a linear correlation between relative m/z shift and visible total charge Qv; determining a relative m/z shift of sample ions detected in a mass spectrum by multiplying visible total charge Qv with the determined slope; and correcting the m/z values in the mass spectrum using its determined relative m/z shift.

Abstract: A protection device for an Optical Emission Spectrometer (OES) and a method of protecting a detector to which purge gas is supplied, in an OES, are disclosed. The protection device comprises a timer, which measures a parameter, such as a humidity value, indicative of a shut down time period following cessation of application of purge gas to the detector. The protection device comprises a processor, which determines a start-up time period, based on the parameter, during which purge gas is supplied to the detector prior to cooling of the detector. The processor may selectively trigger commencing or maintaining application of purge gas to the detector or cooling of the detector in dependence on the parameter.

Abstract: An isotope ratio spectrometer is operated for measurement of a sample. First isotope ratios and first signal intensities are measured for a reference in the spectrometer, over a first measurement time period. A first relationship comprising a relationship between the first isotope ratios and the first signal intensities is determined. Sample isotope ratios and sample signal intensities are measured in the spectrometer, over a second measurement time period subsequent to the first measurement time period. Second isotope ratios and second signal intensities for a reference are measured in the spectrometer, over a third measurement time period subsequent to the second measurement time period. A second relationship comprising a relationship between the second isotope ratios and the second signal intensities is determined. A reference isotope ratio is estimated for a time X within the second measurement time period, based on the first relationship and the second relationship.

Abstract: A method of reducing fragmentation of ions generated from a sample during transport of the ions through an ion transport apparatus that comprises an ion funnel portion, comprises: applying a selected DC potential difference between an outlet end of the ion transport apparatus and an exit ion lens that is disposed adjacent to the outlet end, wherein a sign of the selected DC potential difference is chosen so as to accelerate the ions from the outlet end of the ion transport apparatus towards and through the exit ion lens.

Abstract: The present invention relates to an assembly comprising a vacuum chamber and a time-of-flight mass spectrometer wherein the time-of-flight mass spectrometer is contained within the vacuum chamber. The time-of-flight mass spectrometer comprising a first electrode and a second electrode, the second electrode being spaced apart from the first electrode at a distance defining a portion of an ion-flight path therebetween. The assembly further comprising a first support for supporting the first electrode, the first support arranged between an inner surface of the vacuum chamber and the first electrode. The first support is configured to permit relative movement between at least a portion of the inner surface of the vacuum chamber and the first electrode. The inner surface of the vacuum chamber and the first electrode are thermally coupled. The present invention also relates to a multi-reflection time-of-flight mass analyser.

Abstract: Disclosed herein are systems for imaging and ablating a sample. An imaging/ablating device (110) includes an optical assembly (112), a sample stage (114), and a receiver (116). The optical assembly (112) is disposed in an inverted position below the sample stage (114) and the receiver (116) is positioned above the sample stage (112). The optical assembly enables imaging of a sample disposed on the sample stage (114). The optical assembly (112) also enables ablation of a region of interest within the sample. The laser light propagated from the optical assembly during ablation propagates substantially in the same direction as the direction of travel of the ablation plume (20) toward the receiver (116).

Abstract: A method of determining one or more interference parameters for a particular peak of an isotopic distribution corresponding to a precursor molecule in MS scan data is provided. The MS scan data comprises a plurality of peaks. Each peak has a mass-to-charge ratio and a relative abundance. The isotopic distribution comprises a subset of the plurality of peaks. The one or more interference parameters comprises a peak purity, pi, for the particular peak. The method comprises determining that there are no interfering peaks relevant to the isotopic distribution and determining that the peak purity, pi, for the particular peak should be a maximum purity value.

Abstract: A data processing device comprises a processor unit adapted to process a plurality of initial data vectors provided by a chromatograph and/or a mass spectrometer, the processing being carried out in one, two or more processing steps producing items of processed data, and a storage unit adapted to save and retrieve initial data vectors and/or items of processed data, in particular processed data vectors or identified compounds, and/or items of additional data, in particular properties of the sample introduced in the mass spectrometer. Each item of processed data and/or additional data is connected to at least one initial data vector, and wherein the processor unit is adapted to group, select and/or modify initial data vectors and/or items of processed data according to one or more items of additional data.

Abstract: Trapping ions in an ion trapping assembly is described. In one aspect, this is implemented by introducing ions into the ion trapping assembly, applying a first RF trapping amplitude to the ion trapping assembly so as to trap introduced ions which have m/z ratios within a first range of m/z ratios, and cooling the trapped ions. In some aspects, also performed is reducing the RF trapping amplitude from the first RF trapping amplitude to a second, lower, RF trapping amplitude so as to reduce the low mass cut-off of the ion trapping assembly and trapping, at the second, lower RF trapping amplitude, introduced ions having m/z ratios within a second range of m/z ratios. A lower mass limit of the second range of m/z ratios is below the low mass cut-off of the ion trapping assembly when the first RF trapping amplitude is applied.

Abstract: 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 Qv 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.

Abstract: 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.

Abstract: The ion trap comprises a multipole electrode assembly, a first confining electrode, and a second confining electrode. The multipole electrode assembly is configured to confine ions of the first polarity to an ion channel extending in an axial direction of the multipole electrode assembly. The first confining electrode is provided adjacent to the multipole electrode assembly and extends in the axial direction of the multipole electrode assembly. The second confining electrode is provided adjacent to the multipole electrode assembly and extends in the axial direction of the multipole electrode assembly aligned with the first confining electrode. The first and second confining electrodes are spaced apart in the axial direction in order to define an ion confining region of the ion channel between the first and second confining electrodes.

Abstract: A vacuum pump system for evacuating at least five volumes comprising a turbomolecular pump and a forevacuum pump arranged to pump an output of the turbomolecular pump arrangement to atmosphere. The turbomolecular pump has at least five pumping stages separated by rotor blades. Not more than three pumping stages have pumping speeds in excess of ? of the highest pumping speed when under vacuum and/or a pumping port cross section in excess of ? of the highest pumping port cross section, and at least two pumping stages have pumping speeds less than ¼ of the highest pumping speed when under vacuum and/or a pumping port cross section of less than ¼ of the biggest pumping port cross section. The ratio of pressures between the pumping stage with the highest pressure and the pumping stage with the lowest pressure is at least 100000:1 when under vacuum.

Abstract: An interface for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer that is configured to analyse the received ions at a lower pressure includes an interface vacuum chamber having a downstream aperture; a support assembly defining an axial bore arranged to allow a removable capillary tube to extend therethrough; ions being received from the atmospheric pressure ion source through the capillary tube and directed towards the downstream aperture; and a jet disruptor, positioned downstream from the axial bore and configured to disrupt gas flow between the axial bore and the downstream aperture only when the capillary tube is not fully inserted through the axial bore.

Abstract: A mass spectrometry method comprises: providing a multiplexed sample comprising a mixture of biomolecule-containing samples respectively tagged with mass tags; acquiring MS2 spectra by data-dependent acquisition (DDA) of the multiplexed sample or another mass tagged mixture of the samples during chromatographic elution; acquiring MS2 spectra by data-independent acquisition (DIA) during the elution; forming a spectral library from the DDA MS2 spectra comprising a plurality of the MS2 spectra and the biomolecule retention times; matching fragment-ion peaks in the DIA MS2 spectra to fragment-ion peaks in the MS2 library spectra to find matched biomolecules; determining a total abundance for each matched biomolecule from the DIA MS2 spectra at each of a plurality of retention times; determining abundances of respective reporter ions from the DIA MS2 spectra at the plurality of retention times; and deconvoluting relative abundances of the biomolecules in each respectively tagged biomolecule-containing sample based

Abstract: Ions are injected into an orbital electrostatic trap. An ejection potential is applied to an ion storage device, to cause ions stored in the ion storage device to be ejected towards the orbital electrostatic trap. Synchronous injection potentials are applied to a central electrode of the orbital electrostatic trap and a deflector electrode associated with the orbital electrostatic trap, to cause the ions ejected from the ion storage device to be captured by the electrostatic trap such that they orbit the central electrode. Application of the ejection potential and application of the synchronous injection potentials are each started at respective different times, the difference in times being selected based on desired values of mass-to-charge ratios of ions to be captured by the orbital electrostatic trap.

Abstract: An ion optical arrangement (1) for use in a mass spectrometer comprises electrodes (11) defining an ion optical path, a housing (18) for accommodating the electrodes, a voltage source for providing voltages to the electrodes to produce electric fields, and a valve for allowing gas to enter and/or leave the housing. The valve comprises an electrostatic mechanism and/or a pneumatic mechanism. The electrostatic mechanism may comprise a flexible foil (30, 31) configured for covering at least one opening (16) in the ion optical arrangement when a first voltage is applied and being spaced apart from the at least one opening when a second voltage is applied. The pneumatic mechanism may comprise a Bourdon tube.