435 results about "Time-of-flight mass spectrometry" patented technology

This invention relates to an MALDI-TOF MS (Matrix-assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry)-assisted identification method for listeria monocytogenes, comprising the following steps of: (1) selecting 35 to 40 strains of fresh cultures of listeria monocytogenes, pre-treating the samples; (2) collecting maps of all bacterial strain samples; (3) analyzing and unifying the obtained maps by using BioTyper software to obtain a standard map of listeria monocytogenes; (4) preparing a sample of a microorganism to be detected by adopting the method in the step (1); (5) collecting the MALDI-TOF-MS map of the sample to be detected according to the method in the step (2); comparing the obtained MALDI-TOF-MS map of the sample to be detected in step (5) with the obtained standard map of listeria monocytogenes in the step (3), judging the detection results according to matching fractions. According to the invention, a mass spectrogram database and the standard map in listeria monocytogenes identification are created successfully, and the accurate identification with convenience, microscale and high automation for listeria monocytogenes can be realized.

The time-of-flight mass spectrometers which must demonstrate a high constancy of the calibrated mass scale even under changeable ambient temperatures and thermal loads due to pumps or electronics. Time-of-flight mass spectrometers calculate the masses of ions from the measured time of flight in a long flight tube that is normally manufactured of stainless steel. These flight tubes are subject to temperature-related length changes which affect the flight time and therefore the mass determination. The thermal expansion of spectrometer parts between ion source and ion detector, thus keeping the flight path for the ions at a constant length. Length compensation can be produced by design of the spacing system made of materials of different thermal expansion coefficients, the length changes of which balance out in opposite directions.

A multi-reflecting TOF mass analyser has two parallel, gridless ion mirrors each having an elongated structure in a drift direction (Z). These ion mirrors provide a folded ion path formed by multiple reflections of ions in a flight direction (X), orthogonal to the drift direction (Z). The analyser also has a further gridless ion mirror for reflecting ions in the drift direction (Z). In operation ions are spatially separated according to mass-to-charge ratio due to their different flight times along the folded ion path and ions having substantially the same mass-to-charge ratio are subjected to energy focusing with respect to the flight and drift directions.

The invention relates to a method for the auxiliary identification of comma bacillus by matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). The method comprises the following steps of: 1, selecting 40 to 45 plants of fresh comma bacillus cultures, and pretreating the samples; 2, collecting maps of all bacterial strain samples; 3, analyzing and unitizing the obtained maps by using BioTyper software to obtain a comma bacillus standard map; 4, preparing samples of microbes to be detected by the step 1; 5, collecting MALDI-TOF MS maps of the samples to be detected according to the step 2; and 6, comparing the MALDI-TOF MS maps, which are obtained in the step 5, of the samples to be detected with the comma bacillus standard map, and determining a detection result according to matching fractions. By the method, a comma bacillus identification mass spectrogram database and the comma bacillus standard map are established successfully, so the simple, convenient, microscale, supermatic and accurate identification of the comma bacillus can be realized.

The present invention relates generally to instrumentation and methodology for the characterization of chemical samples in solutions or on a surface which is based on modified ionization methods with or without adjustable pH and controllable H-D exchange in solution, an improved ion mobility spectrometer (IMS), a multi-beam ion pre-selection of the initial flow, and coordinated mobility and mass ion separation and detection using a single or several independent time-of-flight mass spectrometers for different beams with methods for fragmenting ion mobility-separated ions and multi-channel data recording

A means and method are disclosed whereby ions from an ion source can be selected and transferred to a time-of-flight mass analyzer via an arrangement of multipoles in such a way that fragmented ions may be generated by collision-induced dissociation or surface-induced dissociation. First, ions from the source are collisionally cooled by a first multipole. Second, the m/z range of the ions is then selected by a second multipole (preferably a quadrupole). Third, the selected ions are allowed to collide with a "collision surface" capable of producing fragment ions. Fourth, these fragment ions are collisionally cooled in a third multipole and delivered into a TOF mass analyzer for subsequent analysis of the fragmented ions.

A multi-reflection time-of-flight mass spectrometer (MR-TOFMS) and an analysis method are disclosed. The flight paths of the ions are folded along a trajectory through electrostatic mirrors. Longer flight paths provide higher resolution while maintaining a modest instrument size.

A system and method for mass analysis of ions. The system includes an orthogonal acceleration time-of-flight mass analyzer having at least two channels configured to receive respective groups of ions from respective ion sources and having a field-free section configured to mass-separate ions during flight time. The groups of ions are directed to different ones of the channels of the mass analyzer for mass analysis of the respective groups of ions, and at least a part of the field-free section is shared between the channels. The method introduces the ions into an orthogonal acceleration time-of-flight mass analyzer, directs groups of ions from respective ones of the two sources into different channels of the mass analyzer, and simultaneously mass-analyzes the groups of ions from the different channels.

A method and apparatus are provided for identifying analytes at low concentrations in a liquid sample. The liquid sample is introduced through a continuous flow membrane inlet system. The analytes that permeate the membrane are analyzed by photoionization-time-of-flight mass spectrometry. The analytes remaining in the liquid sample that do not permeate the membrane are conducted to a capillary tube inlet that introduces the liquid sample and other analytes as droplets into the photoionization zone. Any analytes remaining absorbed or adsorbed on the membrane are driven through the membrane by application of heat. Analytes may be analyzed by either resonance enhanced multiphoton ionization (REMPI) or single photon ionization (SPI), both of which are provided in the apparatus and can be selected as alternative sources.

A method and apparatus for time-of-flight (TOF) mass spectrometry. The apparatus improves the ion focusing properties in an orthogonal direction and permits connection with an orthogonal-acceleration ion source for improvement of sensitivity. The apparatus comprises an ion source for emitting ions in a pulsed manner, an analyzer for realizing a helical trajectory, and a detector for detecting the ions. The analyzer is composed of plural laminated toroidal electric fields to realize the helical trajectory.

The content of the invention comprises a concept of reactor for isolated ion transformations induced by collisions with neutral species. This reactor is also an interface between mobility cell and orthogonal injection TOFMS based on supersonic adiabatic gas flow with variable controlled composition directed along the axis of a multipole ion guide with sectioned rods for possibility of creating of controlled distributions of RF, DC and AC rotating fields.

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 l00eV), 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 TOF 1 analyzers, combining radio frequency (RF) and quadratic DC fields. RF field retains low-energy ions within TOF 1 analyzer, while quadratic DC field improves resolution by compensate for large relative energy spread.

In a cluster ion beam irradiation apparatus including an apparatus for measuring size and energy distribution of gas cluster ions by using the time of flight (TOF) mass spectrometry, a unit for applying a retarding voltage is disposed in a stage preceding a TOF measuring instrument including a drift tube and a current measuring instrument. By measuring the size and energy distribution of the gas cluster ions and adjusting ionization conditions, cluster ions having predetermined energy and size are supplied to a work surface. In addition, a product of a pressure in an ion transportation device and an ion transportation length is controlled so as to satisfy the relation P×L≦30/N^2/3/E^1/2 Pa.m, where N is the size of gas cluster ions used for irradiation, and E is kinetic energy (eV) of the gas cluster ions.

The invention is directed to a method for detecting low concentrations of bacteria in liquid solution that may or may not be complex liquid solutions. In one embodiment, immunomagnetic separation (IMS) is used to separate target bacterium that may be in a liquid mixture from other constituents in the mixture. A low concentration of a bacteriophage for the target bacteria is subsequently used to infect target bacterial cells that have been captured using the IMS technique. If at least a certain concentration of target bacterium are present, the bacteriophage will multiply to a point that is detectable. Matrix assisted laser desorption ionization/time-of-flight-mass spectrometry (MALDI/TOF-MS) is then used to produce a mass spectrum that is analyzed to determine if one or more proteins associated with the bacteriophage are present, thereby indirectly indicating that target bacterium were present in the liquid mixture.

The use of porous monolithic matrix for matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis on a sample suspected of containing an analyte is herein described. The porous polymer monoliths provide a matrix suitable for use in detecting and analyzing low molecular weight and small molecules. The matrices described herein also facilitate the creation of arrays of monolithic matrices for high-throughput detection and screening using MALDI-TOF mass spectrometry and exhibit a long shelf-life.