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

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.

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.

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.

Time-of-flight mass spectrometer instruments for monitoring fast processes using an interleaved timing scheme and a position sensitive detector are described. The combination of both methods is also described.

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 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

This invention relates to one fly time mass spectrum vacuum ultraviolet isolation device, which comprises the following parts: one ionization chamber fixed with vacuum ultraviolet lamp as ion source; one ion repel electrode in one to four mm to the lamp window and earth electrode at ten to fifteen mm to the dispel electrode; ion repel electrode and earth connection electrode weak field acceleration ion electron for isolation; light exit hole with diameter as two to 8mm down the electrodes; one capillary to lead vacuum ultraviolet lamp front end with light axis vertical to gas sample in direction.

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 reflecting time-of-flight mass spectrometer MR TOF MS 11. the flight path of ions from an ion source 12 to a receiver is folded along a trajectory by two parallel gridless electrostatic mirrors 15, elongated in the shift direction 7, orthogonal to the direction of reflection. A set of multiple lenses 17 is positioned in the drift space 14 between the mirrors to provide for spatial focusing of ions in the plane of the folded ion path. Each mirror consists of at least 4 electrodes 15C, 15E, 15L arranged and controlled so that to improve ion optics properties. Namely, in addition to time-of-flight focusing in energy and spatial focusing across the plane of the folded ion path, the mirrors also provide time-of-flight focusing with respect to the spatial spread of ions across the said plane. Because of improved spatial and time focusing, the MR TOF MS of the invention provides for a wider acceptance and confinement of ion beam along an extended folded ion path.

Time-of-flight mass spectrometer instruments are disclosed for monitoring fast processes with large dynamic range using a multi-threshold TDC data acquisition method or a threshold ADC data acquisition method. Embodiments using a combination of both methods are also disclosed.

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 / N2 / 3 / E1 / 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.

An ion beam supplied from a source is modulated so the ions at a constant flux is deflected by different amounts during two different types of deflection time periods according to a binary sequence, in order to encode the ion beam with phase information of the sequence. The binary sequence is such that ions released during two consecutive time periods of the same type overlap before reaching a detector, thereby increasing the duty cycle. The detector output signal is demodulated using the phase information of the binary sequence to recover an ion mass spectrum.

The invention discloses a method for judging an improtant flavor substance of liquor. The method comprises the steps of diluting a liquor sample to be detected with deionized water till the final alcohol content is 12-14%vol, conducting headspace solid-phase microextraction on a flavor compound in the enriched sample, measuring with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry, conducting fragrance smelling judgment with a smell detector synchronously to qualitatively analyze the major flavor substance of the liquor, and quantitatively analyzing the confirmed important flavor substance of the liquor by a standard curve internal standard method. The method for quickly and comprehensively analyzing key fragrance, characteristic fragrance and important fragrance compounds in the flavor compound of the liquor is established, a technical system integrating a qualitative method, a quantitative method and sensation for the flavor compound of the liquor, and an evaluation system are established, and an effective tool is further provided for analyzing micro constituents of the liquor.

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.