Abstract: A method of assessing the linearity and dynamic range of a mass spectrometer is described comprising analyzing two or more test standards containing positional isomers, for example, using a series of N isomeric analytes with or without an internal standard where N is an integer from 2 to 6 inclusive. The concentrations of the N isomeric analytes may or may not be interleaved between two or more standards. The method allows for repeated instrument characterization without having many of the problems associated with using only a single standard such as octafluoronaphthalene (OFN), for example, persistence, and it may lessen sample carryover issues between adjacent samples. Methods are described using positional isomers of dibromodifluorobenzene in various configurations that show an improved means for qualitative and quantitative analysis of one or more analytes by GC-MS.

Abstract: A method of performing mass spectrometric analyses, comprises: (a) passing a stream of ions through a quadrupole mass analyzer; (b) intercepting a flux of ions emitted from an exit aperture of the quadrupole mass analyzer at a front face of a stack of multichannel plates and emitting a flux of electrons in response to the intercepted flux of ions at a rear face of the stack of multichannel plates; (c) intercepting the flux of electrons at a front surface of a scintillator comprising a phosphorescent material and emitting a flux of photons in response to the intercepted flux of ions at a rear surface of the scintillator; (d) receiving the flux of photons at a photo-imager; and (e) repositioning at least one of the scintillator and the stack of microchannel plates during the execution of one or more of the steps (a) through (d).

Abstract: A capillary column includes a fused silica tubing, a polyimide coating over the fusing silica tubing, and a first plurality of integrated ferrules positioned along at least a first portion of the fused silica tubing and spaced apart from one another by a first fixed interval. Each of the first plurality of integrated ferrules includes a first deformable surface and a second deformable surface. The first plurality of integrated ferrules are secured to the column through deformation of the first deformable surface and the second deformable surface is configured to form a seal with a junction when secured with a nut.

Abstract: A multipole assembly configured to be disposed in a mass spectrometer includes a plurality of elongate electrodes arranged about an axis extending along a longitudinal trajectory of the plurality of elongate electrodes and configured to confine ions radially about the axis, and a piezoelectric actuator configured to adjust a position of a first electrode included in the plurality of elongate electrodes.

Abstract: A multipole assembly configured to be disposed in a mass spectrometer includes a plurality of elongate electrodes arranged about an axis extending along a longitudinal trajectory of the plurality of elongate electrodes and configured to confine ions radially about the axis, and a piezoelectric actuator configured to adjust a position of a first electrode included in the plurality of elongate electrodes.

Abstract: A method of operating a Fourier Transform (FT) mass analyzer, which has a plurality of selectable resolving power settings, includes storing an optimized voltage value in association with each one of the plurality of selectable resolving power settings. More particularly, the optimized voltage values for at least two of the selectable resolving power settings differ from one another. When a user selects one of the plurality of selectable resolving power settings, the optimized voltage value that is stored in association therewith is retrieved. At least one voltage setting of the FT mass analyzer is controlled, based on the retrieved optimized voltage value, and an analytical scan is performed at the selected one of the plurality of selectable resolving power settings for a population of ions within the FT mass analyzer.

Abstract: A method of operating a mass spectrometer comprising: detecting a first ion species using a first gain setting of a detector or a first emission current for a first mass-to-charge range; detecting a second ion species using a second gain setting of the detector or a second emission current for a second mass-to-charge range; and using the detected first and second ion species to calibrate the mass range of a mass analyzer of the mass spectrometer, to tune the resolution of the mass analyzer, or to tune an ion optic of the mass spectrometer.

Abstract: An apparatus for separating ions includes an electrode arrangement having a length extending between first and second ends. The first end is configured to introduce a beam of ions into an ion transmission space of the arrangement. An electronic controller applies an RF potential and a DC potential to an electrode of the electrode arrangement, for generating a ponderomotive RF electric field and a mass-independent DC electric field. The application of the potentials is controlled such that a ratio of the strength of the ponderomotive RF electric field to the strength of the mass-independent DC electric field varies along the length of the electrode arrangement. The generated electric field supports extraction of ions having different m/z values at respective different positions along the length of the electrode arrangement. Ions are extracted in one of increasing and decreasing sequential order of m/z ratio with increasing distance from the first end.

Abstract: A method comprises: (1) making an extract of a biological sample; (2) repeatedly: (a) choosing a respective one of a plurality of pre-determined protein or polypeptide analyte compounds; (b) introducing a portion of the extract into an electrospray ionization source, thereby generating positive ions comprising a plurality of ion species; (c) isolating a plurality of subsets of the ion species comprising respective mass-to-charge (m/z) ratio ranges, each range including an m/z ratio corresponding to a respective protonation state of the chosen compound; (d) reacting the isolated plurality of subsets of first-generation ion species with proton transfer reaction reagent anions for a pre-determined time duration; (e) generating a mass spectrum of the product ion species; and (g) identifying either the presence or absence of the compound based on the mass spectrum; and (3) identifying the presence or absence of the microorganism within the sample based on analytes present.

Abstract: An ion detection system comprises: a stack of microchannel plates comprising a front face and a rear face, the stack disposed so as to receive, at the front face, a flux of ions from an exit aperture of a quadrupole and to emit, at the rear face, a flux of electrons in response to the received flux of ions; a scintillator having a front and a rear surface and disposed so as to receive the flux of electrons at the front surface and to emit, at the rear surface, a flux of photons in response to the received flux of electrons; a photo-imager configured to receive the flux of photons; a power supply; and first, second and third electrodes coupled to the power supply and disposed at the front face, rear face and first surface, respectively, wherein the scintillator comprises a single crystal plate of a phosphorescent material.

Abstract: A magnet assembly for an ion source comprising a first magnet of a first magnet type; a second magnet of a second magnet type; a heat shield located between the first magnet and the second magnet; and a heat sink coupled to the heat shield; wherein the first magnet type having a higher Curie temperature than the second magnet type.

Abstract: Applications of ion-ion reaction chemistry are disclosed in which proton transfer reactions (PTR) combined with higher-collision-energy dissociation (HCD) are used to (1) simplify complex mixture analysis of samples introduced into a mass spectrometer, and (2) improve resolution and sensitivity for the analysis of large proteins in excess of 50 kDa by removing charge, reducing the collisional cross section, and, in several cases, enhancing the sequence coverage obtained.

Abstract: The present disclosure establishes new dissociation parameters that may be used to determine the collision energy (CE) needed to achieve a desired extent of dissociation for a given analyte precursor ion using collision cell type collision-induced dissociation. This selection is based solely on the analyte precursor ion's molecular weight, MW, and charge state, z. Metrics are proposed that may be used as a parameter for the “extent of dissociation”, and then predictive models are developed of the CEs required to achieve a range of values for each metric. Each model is a simple smooth function of only MW and z of the precursor ion. Coupled with a real-time spectral deconvolution (m/z to mass) algorithm, methods in accordance with the invention enable control over the extent of dissociation through automated, real-time selection of collision energy in a precursor-dependent manner.

Abstract: A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.

Abstract: A method includes producing ions from one or more calibrant species and delivering the ions to a mass analyzer, and measuring a first set of mass related physical values for the ions from the one or more calibrant species. The method further includes producing ions from a sample and delivering the ions to a mass analyzer, and measuring a second mass related physical value for a first sample ion species. The first sample ion species has a mass-to-charge ratio outside of the range of the mass-to-charge ratios of the calibrant ion species. Additionally, the method includes calculating a calibration curve based on the first set of mass related physical values and second mass related physical value, and modifying at least one instrument parameter based on the calibration curve.

Abstract: A method for analyzing a sample can include obtaining an exclusion list of retention time and mass-to-charge ranges corresponding to high abundance compounds within a sample; separating components of the sample using the chromatographic column; obtaining a first mass data set using the mass analyzer while excluding ions within retention time and mass-to-charge ranges of the exclusion list; generating an inclusion list of features of the first mass data set; fragmenting ions corresponding to features of the inclusion list; obtaining a second mass data set from the fragmented ions; and identifying and/or quantifying low abundance compounds based on the second mass data set.

Abstract: Systems, methods, and devices to dissociate ions using one or more light emitting diodes (LEDs). A mass spectrometer for ion dissociation includes an ion source for providing ions for dissociation, a mass analyzer, and a photodissociation (PD) device. The PD device includes an ion transport device. The ion transport device is configured perform one or more of: transporting the ions through the PD device, and trapping the ions within a region of the PD device. The PD device also includes one or more LEDs positioned to irradiate the ions in the PD device, resulting in fragmentation of the ions.

Abstract: A method of operating an electrostatic trapping mass analyzer, comprising: introducing a sample of ions into a trapping region of the mass analyzer, wherein a trapping field within the trapping region is such that the ions exhibit radial motion with respect to a central longitudinal axis of the trapping region while undergoing harmonic motion in a dimension defined by the central longitudinal axis, the frequency of harmonic motion of a particular ion being a function of its mass-to-charge ratio; superimposing a modulation field onto the trapping field within the trapping region, the modulation field acting to either increase or reduce the harmonic motion energies of the ions by an amount varying according to the frequency of harmonic motion; and acquiring a mass spectrum of the ions in the trapping region by measuring a signal representative of an image current induced by the harmonic motion of the ions.

Abstract: An embodiment of a method for real time material identification is described that comprises determining an approximate mass value for an unknown material from spectral information derived from mass spectral analysis of the unknown material; retrieving profile models that correspond to a known material from a data structure using the approximate mass value; fitting a sample profile for the unknown material from the spectral information to the profile models to generate a fit score for each fit, wherein the lowest fit score corresponds to the best fit; calculating a mass value from the best fitting profile model and the sample profile.

Abstract: A system for measuring hematocrit in a whole blood sample is provided. An absorbent substrate is adapted to receive a whole blood sample. At least one light source is positioned to illuminate the sample on the substrate at first and second wavelengths. The first and second wavelengths are different from each other. A spectral sensor is positioned to measure a first intensity and a second intensity of light diffusely reflected from the sample at the first and second wavelengths, respectively. The diffusely reflected first and second intensities of light are compared to reference values to generate first and second reflectance values. A controller, coupled to the spectral sensor, is configured to determine a first differential reflectance between the first and second reflectances. The hematocrit level of the sample is determined based on a first stored relationship between hematocrit and a differential reflectance corresponding to the first and second wavelengths.