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: 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: 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: A mass spectrometer system comprises: (a) an ion source; (b) a mass filter; (c) a mass analyzer; (d) a partitioned ion fragmentation cell configured to receive ions from the mass filter and to outlet fragment ions to the mass analyzer comprising: (d1) a set of multipole rod electrodes; a housing enclosing the set of multipole rod electrodes and comprising an ion inlet and an ion outlet; (d2) a set of partitions within the housing separating the housing interior into a plurality of compartments; and (d3) a plurality of gas inlets, each gas inlet fluidically coupled to a source of a collision gas and to a respective compartment and having a respective inlet shutoff valve; and (e) a controller electrically coupled to each inlet shutoff valve and configured to independently control the pressure of collision gas within each compartment.

Abstract: A method for operating a mass spectrometer so as to detect or quantify analytes, comprises: (a) identifying a selected-reaction-monitoring (SRM) transition to be used for each respective analyte; (b) determining a time duration required for a fragmentation reaction corresponding to each identified transition to proceed to a threshold percentage of completion; and (c) for each analyte, performing the steps of (i) isolating ions corresponding to a precursor-ion mass-to-charge (m/z) ratio of the respective transition; (ii) fragmenting the respective isolated ions in one of two fragmentation cells or fragmentation cell portions; and (ii) mass analyzing for fragment ions corresponding to a product-ion m/z ratio of the respective transition, wherein, for each analyte, the fragmentation cell or fragmentation cell portion that is used for fragmenting the isolated ions is determined from the time duration determined for the respective analyte.

Abstract: An ion detection system for a detecting a quantity of ions exiting from a mass analyzer of a mass spectrometer comprises: (a) photon generating means configured to receive the quantity of ions and to generate a quantity of photons that is proportional to the quantity of ions; (b) a linear array of photo-detectors configured along a line for detecting a variation of a portion of the quantity of generated photons along the line; and (c) an optical system for directing the portion of the quantity of photons from the photon generating means to the linear array of photo-detectors comprising: (c1) a first cylindrical lens having a first lens axis disposed parallel to the line; (c2) a second cylindrical lens or rod lens having a second lens axis disposed parallel to the line; and a doublet lens.

Abstract: A method for operating a mass spectrometer so as to detect or quantify analytes, comprises: (a) identifying a selected-reaction-monitoring (SRM) transition to be used for each respective analyte; (b) determining a time duration required for a fragmentation reaction corresponding to each identified transition to proceed to a threshold percentage of completion; and (c) for each analyte, performing the steps of (i) isolating ions corresponding to a precursor-ion mass-to-charge (m/z) ratio of the respective transition; (ii) fragmenting the respective isolated ions in one of two fragmentation cells or fragmentation cell portions; and (ii) mass analyzing for fragment ions corresponding to a product-ion m/z ratio of the respective transition, wherein, for each analyte, the fragmentation cell or fragmentation cell portion that is used for fragmenting the isolated ions is determined from the time duration determined for the respective analyte.

Abstract: A method of mass analysis comprises: generating ions from the sample; delivering the ions to a quadrupole; applying a radio frequency voltage, V, to rods of the quadrupole such that the instantaneous electrical potential of each rod is out of phase with each adjacent rod and a non-oscillatory voltage, U, across each pair of adjacent rods such that a subset of the ions having a range of mass-to-charge (m/z) ratios are selectively transmitted through the quadrupole; varying at least one of voltage U and voltage V such that the range of selectively transmitted m/z ratios is caused to vary and varying at least one additional operational parameter; acquiring a data set comprising a series of temporally-resolved images of spatial distribution patterns of transmitted ions at each combination of U, V and the at least one additional operating parameter; and mathematically deconvolving the data set to generate mass spectra.

Abstract: A detector system for a mass spectrometer comprises: a metal channel dynode (MCD) comprising at least one perforated metal plate configured to receive the exiting ions and eject electrons in response; a plurality of electron-to-photon converters arranged in a parallel stacked configuration, each such converter comprising a substrate plate having a phosphor coating on a first face; and an electrode film disposed on the phosphor coating; at least one photocathode, each of the at least one photocathode disposed between a respective pair of the plurality of electron-to-photon converters; an optical detector optically coupled a last one of the electron-to-photon converters; and at least one direct current power supply configured to apply, in operation, a respective bias electrical potential to the MCD and each of the electrode films and photocathodes.

Abstract: A method of mass analysis comprises: generating ions from the sample; delivering the ions to a quadrupole; applying a radio frequency voltage, V, to rods of the quadrupole such that the instantaneous electrical potential of each rod is out of phase with each adjacent rod and a non-oscillatory voltage, U, across each pair of adjacent rods such that a subset of the ions having a range of mass-to-charge (m/z) ratios are selectively transmitted through the quadrupole; varying at least one of voltage U and voltage V such that the range of selectively transmitted m/z ratios is caused to vary and varying at least one additional operational parameter; acquiring a data set comprising a series of temporally-resolved images of spatial distribution patterns of transmitted ions at each combination of U, V and the at least one additional operating parameter; and mathematically deconvolving the data set to generate mass spectra.

Abstract: A collision cell has a plurality of rod electrodes arranged in opposed pairs around an axial centerline and a plurality of drag vanes arranged in the interstitial spaces between the rod electrodes. Operating the collision cell includes, applying a rod offset voltage to the rod electrodes, and varying an offset voltage applied to the drag vanes to identify a vane offset voltage with a maximum intensity for the transition. The method further includes varying a drag field by adjusting the voltages applied to drag vane terminals in opposite directions to identify a drag field value with a cross talk below a cross talk threshold, varying the vane offset voltage by adjusting the voltages applied to the drag vane terminals to maximize the intensity of the transition while preserving the drag field, and operating the collision cell at the vane offset voltage and drag field to monitor the transition.

Abstract: An ion detection system for a detecting a quantity of ions exiting from a mass analyzer of a mass spectrometer comprises: (a) photon generating means configured to receive the quantity of ions and to generate a quantity of photons that is proportional to the quantity of ions; (b) a linear array of photo-detectors configured along a line for detecting a variation of a portion of the quantity of generated photons along the line; and (c) an optical system for directing the portion of the quantity of photons from the photon generating means to the linear array of photo-detectors comprising: (c1) a first cylindrical lens having a first lens axis disposed parallel to the line; (c2) a second cylindrical lens or rod lens having a second lens axis disposed parallel to the line; and a doublet lens.

Abstract: A detector system for a mass spectrometer comprises: a metal channel dynode (MCD) comprising at least one perforated metal plate configured to receive the exiting ions and eject electrons in response; a plurality of electron-to-photon converters arranged in a parallel stacked configuration, each such converter comprising a substrate plate having a phosphor coating on a first face; and an electrode film disposed on the phosphor coating; at least one photocathode, each of the at least one photocathode disposed between a respective pair of the plurality of electron-to-photon converters; an optical detector optically coupled a last one of the electron-to-photon converters; and at least one direct current power supply configured to apply, in operation, a respective bias electrical potential to the MCD and each of the electrode films and photocathodes.

Abstract: An ion detection system for a detecting a quantity of ions exiting from a mass analyzer of a mass spectrometer comprises: (a) photon generating means configured to receive the quantity of ions and to generate a quantity of photons that is proportional to the quantity of ions; (b) a light collection lens optically coupled to the photon generating means and configured to transmit a beam of the generated photons; (c) line focusing means operable to focus at least a first portion of the beam to a line; and (d) a linear array of photo-detectors configured to detect a variation of the quantity of generated photons along the focused line.

Abstract: A collision cell has a plurality of rod electrodes arranged in opposed pairs around an axial centerline and a plurality of drag vanes arranged in the interstitial spaces between the rod electrodes. Operating the collision cell includes, applying a rod offset voltage to the rod electrodes, and varying an offset voltage applied to the drag vanes to identify a vane offset voltage with a maximum intensity for the transition. The method further includes varying a drag field by adjusting the voltages applied to drag vane terminals in opposite directions to identify a drag field value with a cross talk below a cross talk threshold, varying the vane offset voltage by adjusting the voltages applied to the drag vane terminals to maximize the intensity of the transition while preserving the drag field, and operating the collision cell at the vane offset voltage and drag field to monitor the transition.

Abstract: Non-negative contributions to a spectrum from time-varying spectroscopy data can be determined. Reference basis functions can transform spectroscopy data into an equation (e.g., an objective function). Each reference basis function can correspond to a different time and a different particle, e.g., a different mass. The objective function can include a noise vector that modifies the spectroscopy data to provide a solution that is constrained to be non-negative. The noise vector can be estimated by minimizing the objective function to obtain an estimated vector, which can be truncated that satisfies a given constraint. The noise vector can be computed from the difference of the estimated vector and the truncated vector, and be accumulated. The noise vector can be used to update the objective function, thereby providing a new estimated vector in an iterative loop.

Abstract: A novel method and mass spectrometer apparatus is introduced to spatially and temporally resolve images of one or more ion exit patterns of a multipole instrument. In particular, the methods and structures of the present invention measures the ion current as a function of time and spatial displacement in the beam cross-section of a quadrupole mass filter via an arrayed detector. The linearity of the detected quadrupole ion current in combination with it reproducible spatial-temporal structure enables the deconvolution of the contributions of signals from individual ion species in complex mixtures where both sensitivity and mass resolving power are essential.

Abstract: A novel method and mass spectrometer apparatus is introduced to spatially and temporally resolve images of one or more ion exit patterns of a multipole instrument. In particular, the methods and structures of the present invention measures the ion current as a function of time and spatial displacement in the beam cross-section of a quadrupole mass filter via an arrayed detector. The linearity of the detected quadrupole ion current in combination with it reproducible spatial-temporal structure enables the deconvolution of the contributions of signals from individual ion species in complex mixtures where both sensitivity and mass resolving power are essential.

Abstract: A novel method and mass spectrometer apparatus is introduced to spatially and temporally resolve images of one or more ion exit patterns of a multipole instrument. In particular, the methods and structures of the present invention measures the ion current as a function of time and spatial displacement in the beam cross-section of a quadrupole mass filter via an arrayed detector. The linearity of the detected quadrupole ion current in combination with it reproducible spatial-temporal structure enables the deconvolution of the contributions of signals from individual ion species in complex mixtures where both sensitivity and mass resolving power are essential.

Abstract: A novel method and mass spectrometer apparatus is introduced to spatially and temporally resolve images of one or more ion exit patterns of a multipole instrument. In particular, the methods and structures of the present invention measures the ion current as a function of time and spatial displacement in the beam cross-section of a quadrupole mass filter via an arrayed detector. The linearity of the detected quadrupole ion current in combination with it reproducible spatial-temporal structure enables the deconvolution of the contributions of signals from individual ion species in complex mixtures where both sensitivity and mass resolving power are essential.