740 results about "Mass-to-charge ratio" patented technology

Described are techniques for processing data. Sample analysis is performed generating scans of data. Each scan comprises a set of data elements each associating an ion intensity count with a plurality of dimensions including a retention time dimension and a mass to charge ratio dimension. The scans are analyzed to identify one or more ion peaks. Analyzing includes filtering a first plurality of the scans producing a first plurality of filtered output scans. The filtering including first filtering producing a first filtering output, wherein the first filtering includes executing a plurality of threads in parallel which apply a first filter to the first plurality of scans to produce the first filtering output. Each of the plurality of threads computes at least one filtered output point for at least one corresponding input point included in the plurality of scans. Analyzing includes detecting one or more peaks using the filtered output scans.

A method of inhibiting the reaction between ions of opposite polarity is disclosed. The method includes exposing a population of ions to a resonance excitation frequency during a mass-to-charge altering reaction between a first subpopulation of ions and a second subpopulation of ions, the resonance excitation frequency being tuned to inhibit the mass-to-charge altering reaction between an ion of the first subpopulation of ions having a predetermined mass-to-charge ratio and an ion of the second subpopulation of ions so that when an ion of the first subpopulation of ions attains the predetermined mass-to-charge ratio, the ion having the predetermined mass-to-charge ratio is selectively inhibited from reacting with ions of the second subpopulation of ions.

Multipole ion guides configured with one or mote segments and positioned in a higher pressure vacuum region, are operated in mass to charge selection and ion fragmentation modes. Individual multipole ion guides are mounted in a linear assembly with no electrodes configured in between each multipole ion guide. At least a portion of each multipole ion guide mounted in a linear assembly resides in a vacuum region with higher background pressure. At least one ion guide can be configured to extend continuously from one vacuum stage into another. Individual sets of RF, +/− DC and secular frequency voltage supplies provide potentials to the rods of each multipole ion guide allowing the operation of ion transmission, ion trapping, mass to charge selection and ion fragmentation functions independently in each ion guide. The presence of higher background pressure along a portion of the multiple ion guide linear assembly allows the Collisional Induced Dissociation (CID) fragmentation of ions by axially accelerating ions from one multipole ion guide to an adjacent ion guide, analogous to a triple quadrupole function. A variety of MS and MS/MSⁿ analysis functions can be achieved with a mass analyzer configured with multiple ion guide linear assembly operated in a higher background pressure.

A mass spectrometer is disclosed wherein the experimentally determined mass to charge ratios of ions are reported together with an error band for each mass to charge ratio determination. The error band may, for example, reflect a 95% probability or confidence that the real, true, actual or accepted mass to charge ratio of the ion lies within the error band. By accurately determining the error band the possible candidate ions in a database can be accurately restricted whilst also guarding against over restriction.

The invention “Ion Trap Array (ITA)” pertains generally to the field of ion storage and analysis technologies, and particularly to the ion storing apparatus and mass spectrometry instruments which separate ions by its character such as mass-to-charge ratio. The aim of this invention is providing an apparatus for ion storage and analysis comprising at least two or more rows of parallel placed electrode array wherein each electrode array includes at least two or more parallel bar-shaped electrodes, by applying different phase of alternating current voltages on different bar electrodes to create alternating electric fields inside the space between two parallel electrodes of different rows of electrode arrays, multiple linear ion trapping fields paralleled constructed in the space between the different rows of electrode arrays which are open to adjacent each other without a real barrier. This invention also provides a method for ion storage and analysis involving with the trapping, cooling and mass-selected analyzing of ions by this apparatus mentioned which constructs multiple conjoint linear ion trapping fields in the space between the different rows of electrode arrays

The present invention provides a time of flight mass spectrometer having a spiral flight path, whose mass resolution can be appropriately changed with respect to the analysis object or other factor without any complicated alteration or addition of the mechanical construction. In a specific form of the invention, the mass spectrometer includes deflecting electrodes 20-23 located between semi-cylindrical electrodes 11 and 12 for making ions fly along a spiral path. The deflecting electrodes 20-23 generate deflecting electric fields for shifting the ions in the axial direction of the semi-cylindrical electrodes 11 and 12. The voltage applied to the deflecting electrodes 20-23 is changed according to the mass resolution required. The deflecting electric fields are generated or removed with the change of the voltage, which makes the ions fly either along a spiral path or in the same loop orbit. The flight distance of the ions can be controlled as desired by regulating the voltage so that the ions fly in the loop orbit an appropriate number of times. Thus, the mass resolution can be arbitrarily controlled.

A method for manipulating ions in an ion trap includes storing ions, spatially compressing, and ejecting selected ions according to mass-to-charge ratio. An ion trap includes an injection port, an arm having a first and a second end for confining and spatially compressing the ions, and an ejection port for ejecting the ions from the second end. The arm includes two pairs of opposing electrodes, which provide a quadrupole electric field potential at any cross-section of the ion trap. The distance between opposing electrodes and the cross-sectional area of the electrodes increases from the first to second end. The electrodes may be tapered cylindrical rods or of hyperbolic cross-section. Ions selected for ejection are spatially compressed into a region at the second (wider) end. The ion trap may include one arm, with either orthogonal or axial ejection, or two arms with a central insert for orthogonal ejection.

In the mass spectrometer of the present invention, a flight space is provided before the mass analyzer, and the flight space includes a loop orbit on which ions fly repeatedly. While ions fly on the loop orbit repeatedly, ion selecting electrodes placed on the loop orbit selects object ions having a specific mass to charge ratio in such a manner that, for a limited time period when the object ions are flying through the ion selecting electrodes, an appropriate voltage is applied to the ion selecting electrodes to make them continue to fly on the loop orbit, but otherwise to make or let other ions deflect from the loop orbit. If ions having various mass to charge ratios are introduced in the loop orbit almost at the same time, the object ions having the same mass to charge ratio continue to fly on the loop orbit in a band, but ions having mass to charge ratios different from that are separated from the object ions while flying on the loop orbit repeatedly. Even if the difference in the mass to charge ratio is small, the separation becomes large when the number of turns of the flight becomes large. After such a separation is adequately achieved, the ion selecting electrodes can select the object ions with high selectivity, or at high mass resolution. By adding dissociating means, fragment ions originated only from the selected object ions can be analyzed, which enables the identification and structural analysis of the sample at high accuracy.

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.

A mass spectrometer is disclosed wherein a relatively energetic pulse of ions having a relatively narrow spread of mass to charge ratios are ejected from a quadrupole ion trap and received in an ion trap upstream of a Time of Flight mass analyser. The ions are collisionally cooled within the ion trap and are pulsed out of the ion trap and into an extraction region of the Time of Flight mass analyser without substantially exciting the ions. This enables improved operation with the Time of Flight mass analyser. According to another embodiment, parent ions are fragmented and the resulting fragment ions are stored in two ion traps having different low mass cut-offs. The trapping system enables MS/MS experiments to be performed with a very high duty cycle.

A mass spectrometer is disclosed comprising an ion trap wherein ions which have been temporally separated according to their mass to charge ratio or ion mobility enter the ion trap. Once at least some of the ions have entered the ion trap, a plurality of ion trapping regions are created along the length of the ion trap in order to fractionate the ions. Alternatively, the ions may be received within one or more axial trapping regions which are translated along the ion trap with a velocity which is progressively reduced to zero.

A method for fragmentation of analyte ions for mass spectroscopy and a system for mass spectroscopy. The method produces gas-phase analyte ions, produces gas-phase radical species separately from the analyte ions, and mixes the gas-phase analyte ions and the radical species at substantially atmospheric pressure conditions to produce fragment ions prior to introduction into a mass spectrometer. The system includes a gas-phase analyte ion source, a gas-phase radical species source separate from the gas-phase analyte ion source, a mixing region where the gas-phase analyte ions and the radical species are mixed at substantially atmospheric pressure to produce fragment ions of the analyte ions, a mass spectrometer having an entrance where at least a portion of the fragment ions are introduced into a vacuum of the mass spectrometer, and a detector in the mass spectrometer which determines a mass to charge ratio analysis of the fragment ions.

Apparatus including an ion trap, a controller connected to the ion trap, wherein the controller includes a memory containing computer readable instructions which, when executed, cause the controller to send control signals to the ion trap so that the ion trap produce and maintain a trapping field in the ion trap, a waveform generator to change the trapping field so that ions of a predetermined mass in the trapping chamber are selectively moved; a secondary waveform generator to change the orbits of the ions; an energy source to excite ions to emit photons, an optical detector to detect the emitted photons, and a processor which can apply fast-Fourier transform analysis of the time-domain signal of the detected emitted photons to generate a frequency or mass spectrum related to mass-to-charge ratio of the ions.

A sample S is irradiated with a two-dimensionally spread ray of laser light to simultaneously ionize substances within a two-dimensional area on the sample. The resultant ions are mass-separated by a TOF mass separator 4 without changing the interrelationship of the emission points of the ions. The separated ions are then directed to a two-dimensional detector section 7 through a deflection electric field created by deflection electrodes 61 and 62. The two-dimensional detector section 7 consists of a plurality of detection units 7a arranged in parallel, each unit including an MCP8a, fluorescent plate 9a and two-dimensional array detector 10a. The magnitude of deflecting the flight path of the ions by the deflection electric field is changed in a stepwise manner with the lapse of time from the generation of the ions so that a plurality of mass analysis images are sequentially projected on each detection unit 7. When the mass analysis image shifts from one detection unit to another, the data acquisition operation by the two-dimensional array detector in the previous detection unit is discontinued. As a result, a predetermined number of the latest images are held inside the detector. Thus, the measurement time can be extended to widen the measurable mass-to-charge ratio range, while ensuring a high mass resolution.

The invention belongs to the quality analysis technology field and in particular relates to a method of using a plurality of ion traps for the tandem mass spectrometric analysis, including that a high frequency capturing electric field based on a quadrupole field is produced in the first ion trap for capturing ions with various mass-to-charge ratios. A dipolar excitation alternating electric field with certain frequency along the direction of a straight line for connecting the center of the first ion trap center with the center of a second ion trap center is produced in the first ion trap. Thus, the ions with a mass-to-charge ratio oscillate along the direction to reach to the large amplitude under the resonance excitation. Furthermore, a discharged pulse electric field generates in a specific phase of the first ion trap. The ions reaching to the large moving amplitude are discharged and enter the second ion trap. And the ions with other mass-to-charge ratios are still left in the first ion trap. Through a deceleration field added in the second ion trap or the gas collision, the entering ions or byproduct ions are captured and the researching analysis is further made in the second ion trap.

The invention provides methods, reagents and kits for amino acid, peptide and protein identification, differential quantitation and for the analysis of post translational modification and cross-linking status, comprising: derivatizing a mixture of amino acids peptides or proteins, to form at least one amino acid peptide or protein containing a fixed-charge ion, other than at the C-terminal or N-terminal end thereof; introducing the mixture of amino acids peptides or proteins containing the fixed charge derivatized amino acid peptide or protein to a mass spectrometer; passing the mixture of amino acids peptides or proteins containing the fixed charge derivatized amino acid peptide or protein through a first mass resolving spectrometer to select precursor protein or peptide ions having a first desired mass-to-charge ratio; subjecting the precursor ions of the first mass to charge ratio to dissociation to form a product ion having a second mass-to-charge ratio that is characteristic of a fragmentation occurring at a site adjacent to the fixed charge; and detecting the product ions having the second mass-to-charge ratio. The product ion having the second mass-to-charge ratio may be either a product ion formed by neutral loss of the fixed charge from the precursor ion, or a product ion formed by charged loss of the fixed charge from the precursor ion.

The invention provides a spectrum library generating method, comprising the following steps: selecting analyzed spectrograms of an experimental tandem mass spectrometry, in which information of female ionic peptide sequences, electronic charges, modified types and sites are included; removing redundant spectrograms from the analyzed spectrograms of the experimental tandem mass spectrometry to obtain representing spectrograms; dividing the female ionic peptide sequences corresponding to the representing spectrograms according to a theoretical fragmentation mode to obtain theoretical spectrograms corresponding to the representing spectrograms; combining the theoretical spectrograms and the representing spectrograms to obtain optimized spectrograms; and labeling spectral peaks for the optimized spectrograms, and utilizing the optimized spectrograms with labeled spectral peaks to generate a spectrogram database. The invention further provides a spectrogram identifying method of the tandemmass spectrometry. In the invention, in the process of matching candidate spectrograms and the spectrograms of the tandem mass spectrometry to be analyzed, mass-to-charge ratio offset of the spectralpeak possibly introduced by a potential modification is concerned so that ionic spectral peak containing modified fragments is matched, thereby achieving better modified spectrogram identifying effect.

In a time of flight mass spectrometer (TOF-MS) of the present invention, a flight controller makes ions fly a loop orbit a predetermined number of turns, and an ion detector detects the ions at each turn of the flight. A flight time measurer measures the length of flight time of ions of a same mass to charge ratio at every turn, and a data processor constructs a spectrum of flight time. The data processor further computes the Fourier transformation of the spectrum, and determines the mass to charge ratio of the ions based on a frequency peak appearing in the Fourier transformation.

The present invention provides a mass spectrometer having an ion lens capable of transporting an ion having a large mass to charge ratio with a high level of ion-passing efficiency even under a low-vacuum atmosphere. In conventional atmospheric pressure ionization mass spectrometers or similar mass spectrometers, applying an excessively high voltage to the ion lens undesirably causes an electric discharge. Therefore, the passing efficiency for an ion having a large mass to charge ratio cannot be adequately improved, which leads to a poor detection sensitivity. To solve this problem, the mass spectrometer according to the present invention includes a voltage controller 21 that controls a variable radiofrequency (RF) voltage generator 24 so that both the amplitude and the frequency of the RF voltage applied to the lens electrodes of an ion lens 5 are changed according to the mass to charge ratio of an ion to be analyzed. This control enables the ion lens 5 to focus an ion and transport it to the subsequent stage with a high level of passing efficiency even in the case of analyzing an ion having a large mass to charge ratio. Thus, the detection sensitivity is improved. The aforementioned control is conducted on the basis of the control data stored in a voltage control data storage 22. These data are obtained in advance by a measurement of a sample containing a substance having a known mass to charge ratio, in which the intensity of the signal of an ion detector is maintained while the analysis conditions are changed.

The invention relates to a qualitative and quantitative analysis method for polyoses, which comprises the following steps: (1) the zymohydrolysis and the verification of the polyoses: measuring the content of a polyoses water solution by a colorimetric method; (2) comparing the change of a polyoses mapping before and after zymohydrolysis by HPSEC-ELSD analysis; (3) saccharide ingredient direct HPLC analysis of a polyoses zymohydrolysis solution or HPLC analysis after pre-column derivatization: identifying polyoses mapping and chromatogram peaks by taking a standard monosaccharose, a uronic acid, a disaccharide, and the like as contrasts and taking a chromatogram peak mass-to-charge ratio as reference, and using stable characteristic sections as a quantitative analysis index; and (4) realizing the qualitative and quantitative analysis of the polyoses by establishing polyoses zymohydrolysis responding characteristics and polyoses zymohydrolysis mapping which are based on structural information through the independent or combining application of the steps. The qualitative and quantitative analysis method can be used for the identification and quantitative measurement of the polyoses of traditional Chinese medicine, such as panax, panax pseudoginseng, gen-seng, aweto, cordyceps, ganoderma lucidum, fomes japonica, milk veteh, angelica, and the like and provides an effective method for controlling the quality of the polyoses and the products thereof.

The present invention comprises apparatus and methods for rapidly and accurately determining mass-to-charge ratios of molecular ions produced by a pulsed ionization source, and for fragmenting substantially all of the molecular ions produced while rapidly and accurately determining the intensities and mass-to-charge ratios of the fragments produced from each molecular ion.

A method for reducing the energy spread of ions over a specific and limited mass to charge ratio range is disclosed, along with an ion deceleration arrangement for implementing such a method. An electric field, having an electric field strength E is generated by a deceleration electrode arrangement (250). Ions of a specific and limited mass to charge ratio range, but having a spread of energies, are directed into the decelerating electric field generated by the deceleration electrode arrangement (250). The decelerating electric field is then removed, once substantially all of the ions of the specific mass to charge ratio range have entered the decelerating electric field. By matching the electric field strength E to the energy spread of the ions upon entry into the electric field, the energy spread of the said ions is reduced. Preferred embodiments of the invention employ energy dispersion upstream of the ion deceleration arrangement. For example, an ion mirror arrangement (200) may be used, the ions reflecting off an ion mirror (220) within that ion mirror arrangement (200) to promote energy defocusing.

A TOF mass analyzer having multiple flight paths is described. The TOF mass analyzer includes a pulsed ion source that generates a packet of ions and that accelerates the packet of ions. An ion deflector directs a first group of ions from the packet of ions to a first ion path, and a second group of ions to a second ion path for each of a first and second predetermined time interval after the pulsed ion source generates the packet of ions. A first TOF mass separator separates the first group of ions according to their mass to-charge ratio and a first detector is positioned to receive the first group of ions A second TOF mass separator separates a second group of ions according to their mass to-charge ratio and a second detector is positioned to receive the second group of ions. Additional ion paths may be employed, and any type of TOF mass separator may be used in each ion path.