2020results about "Time-of-flight spectrometers" patented technology

The methods disclosed herein relate to methods and compositions for amplifying nucleic acid sequences, more specifically, from nucleic acid sequences of pathogens by targeted whole genome amplification.

A nanodosimeter device (15) for detecting positive ions induced in a sensitive gas volume by a radiation field of primary particle, comprising an ionization chamber (10) for holding the sensitive gas volume to be irradiated by the radiation field of primary particles; an ion counter system connected to the ionization chamber (10) for detecting the positive ions which pass through the aperture opening and arrive at the ion counter (12) at an arrival time; a particle tracking system for position-sensitive detection of the primary particles passing through the sensitive gas volume; and a data acquisition system capable of coordinating the readout of all data signals and of performing data analysis correlating the arrival time of the positive ions detected by the ion counter system relative to the position sensitive data of primary particles detected by the particle tracking system. The invention further includes the use of the nanodosimeter for method of calibrating radiation exposure with damage to a nucleic acid within a sample. A volume of tissue-equivalent gas is radiated with a radiation field to induce positive ions. The resulting positive ions are measured and compared with a determination of presence or extent of damage resulting from irradiating a nucleic acid sample with an equivalent dose of radiation.

To provide comprehensive (i.e. rapid and sensitive) MS-MS analysis, the inventor employs a time-nested separation, using two time-of-flight (TOF) mass spectrometers. Parent ions are separated in a slow and long TOF1, operating at low ion energy (1 to 100 eV), and fragment ions are mass analyzed in a fast and short TOF2, operating at much higher keV energy. Low energy fragmentation cell between TOF1 and TOF2 is tailored to accelerate fragmentation and dampening steps, mostly by shortening the cell and employing higher gas pressure. Since separation in TOF1 takes milliseconds and mass analysis in TOF2—microseconds, the invention provides comprehensive MS-MS analysis of multiple precursor ions per single ion pulse. Slow separation in TOF1 becomes possible with an introduction of novel TOF1 analyzers. The TOF-TOF could be implemented using a static TOF1, here described on the examples of spiratron, planar and cylindrical multi-pass separators with griddles spatial focusing ion mirrors. Higher performance is expected with the use of novel hybrid TOF1 analyzers, combining radio frequency (RF) and quadratic DC fields. RF field retains low-energy ions within TOF1 analyzer, while quadratic DC field improves resolution by compensate for large relative energy spread.

A mass spectrometer is disclosed wherein ions having a particular desired charge state are selected by operating an ion mobility spectrometer in combination with a quadrupole mass filter. Precursor ions are fragmented or reacted to form product ions in a collision cell ion trap and sent back upstream to an upstream ion trap. The fragment or product ions are then passed through the ion mobility spectrometer wherein they become temporally separated according to their ion mobility. Fragment or product ions are then re-trapped in the collision cell ion trap before being released therefrom in packets. A pusher electrode of a time of flight mass analyzer is energized a predetermined period of time after a packet of ions is released from the collision cell ion trap. Accordingly, it is possible to select multiply charged precursor ions from a background of singly charged ions, fragment them, and mass analyze the fragment ions with a near 100% duty cycle across the whole mass range.

This invention relates to tandem mass spectrometry and, in particular, to tandem mass spectrometry using a linear ion trap and a time of flight detector to collect mass spectra to form a MS / MS experiment. The accepted standard is to store and mass analyze precursor ions in the ion trap before ejecting the ions axially to a collision cell for fragmentation before mass analysis of the fragments in the time of flight detector. This invention makes use of orthogonal ejection of ions with a narrow range of m / z values to produce a ribbon beam of ions that are injected into the collision cell. The shape of this beam and the high energy of the ions are accommodated by using a planar design of collision cell. Ions are retained in the ion trap during ejection so that successive narrow ranges may be stepped through consecutively to cover all precursor ions of interest.

A non-radioactive atmospheric pressure device for ionization of analytes comprises an atmospheric pressure chamber having an inlet for carrier gas, a first electrode at one end, and a counter-electrode at the other end of the chamber for creating an electrical discharge in the carrier gas thus creating metastable neutral excited-state species. Optionally, a grid is provided to generate electrons or ions by contact with the excited-state species. The carrier gas containing the excited-state species or the electrons generated therefrom is directed at an analyte at atmospheric pressure near ground potential to form analyte ions.

To provide comprehensive MS—MS analysis, a time-nested separation is employed using two time-of-flight (TOF) mass spectrometers. Parent ions are separated in a slow and long TOF1, operating at low ion energy (1 to 100eV), and fragment ions are mass analyzed in a fast and short TOF2, operating at much higher keV energy. A low energy fragmentation cell between TOF1 and TOF2 is tailored to accelerate fragmentation and dampening steps, mostly by shortening the cell and employing higher gas pressure. Slow separation in TOF1 becomes possible with an introduction of novel TOF1 analyzers. Higher performance is expected with the use of novel hybrid TOF1 analyzers, combining radio frequency (RF) and quadratic DC fields. An RF field retains low-energy ions within a TOF1 analyzer, while a quadratic DC field improves resolution by compensating for a large relative energy spread.

A method is described for producing tubular substrates having parallel spaced concentric rings of electrical conductors that can be used as the drift tube of an Ion Mobility Spectrometer (IMS). The invention comprises providing electrodes on the inside of a tube that are electrically connected to the outside of the tube through conductors that extend between adjacent plies of substrate that are combined to form the tube. Tubular substrates are formed from flexible polymeric printed wiring board materials, ceramic materials and material compositions of glass and ceramic, commonly known as Low Temperature Co-Fired Ceramic (LTCC). The adjacent plies are sealed together around the electrode.

A nonradioactive atmospheric pressure method for ionization of analytes comprises creating an electrical discharge in a carrier gas thus creating metastable neutral excited-state species. The carrier gas containing the excited-state species is directed into a reactant gas to form ions of the reactant gas. The ionized reactant gas is then directed at the analytes at atmospheric pressure near ground potential to form analyte ions.

An ion mobility / mass spectrometry method and instrument using aerosolized samples and dual positive and negative mode detection is described. Sample preparation methods are also described.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

The present invention relates generally to a multi-reflecting time-of-flight mass spectrometer (MR TOF MS). To improve mass resolving power of a planar MR TOF MS, a spatially isochronous and curved interface may be used for ion transfer in and out of the MR TOF analyzer. One embodiment comprises a planar grid-free MR TOF MS with periodic lenses in the field-free space, a linear ion trap for converting ion flow into pulses and a C-shaped isochronous interface made of electrostatic sectors. The interface allows transferring ions around the edges and fringing fields of the ion mirrors without introducing significant time spread. The interface may also provide energy filtering of ion packets. The non-correlated turn-around time of ion trap converter may be reduced by using a delayed ion extraction from the ion trap and excessive ion energy is filtered in the curved interface.

The present invention enhances the laser desorption of biological molecular ions from surfaces by creating a surface localized MALDI particle matrix by ion implantation of low energy ionized clusters (gold, aluminum, etc.) or chemically derivatized clusters into the near surface region of the sample. MALDI analysis of the intact biomolecules on the surface or within a narrow subsurface region defined by the implantation range of the ions can then be performed by laser desorption into a mass spectrometer or, in a preferred embodiment, into a combined ion mobility orthogonal time of flight mass spectrometer.

A system for the stand-off detection of trace amounts of analyte materials such as explosives, chemical warfare agents, toxic industrial chemicals, and the like includes an ion source that is operably connected to an ion collection means and to a sensor. The ion source employs a first gas that is passed through an electrical discharge to produce metastable gas molecules as well as charged particles of various kinds. Ions and other charged particles are removed from the first gas which is then reacted with a second gas having a lower ionization potential to obtain reactant ions of relatively uniform energy. The reactant ions are focused and accelerated into a beam that is directed upon a surface, such as luggage or clothing that is being interrogated, to produce analyte ions which are collected and passed into the sensor that is preferably a differential mobility spectrometer.