1243 results about "Mass" patented technology

A new geometry ion trap and its use as a mass spectrometer is described. The ion traps can be combined linearly and in parallel to form systems for mass storage, analysis, fragmentation, separation, etc. of ions. The ion trap has a simple rectilinear geometry with a high trapping capacity. It can be operated to provide mass analysis in the mass-selective instability mode as well as the mass-selective stability mode. Arrays of multiple ion traps allow combinations of multiple gas-phase processes to be applied to the trapped ions to achieve high sensitivity, high selectivity and / or higher throughput in the analysis of ions.

A system and method for analyzing and imaging a sample containing molecules of interest combines modified MALDI mass spectrometer and SNOM devices and techniques, and includes: (A) an atmospheric-pressure or near-atmospheric-pressure ionization region; (B) a sample holder for holding the sample; (C) a laser for illuminating said sample; (D) a mass spectrometer having at least one evacuated vacuum chamber; (E) an atmospheric pressure interface connecting said ionization region and said mass spectrometer; (F) a scanning near-field optical microscopy instrument comprising a near-field probe for scanning the sample; a vacuum capillary nozzle for sucking in particles which are desorbed by said laser, the nozzle being connected to an inlet orifice of said atmospheric pressure interface; a scanner platform connected to the sample holder, the platform being movable to a distance within a near-field distance of the probe; and a controller for maintaining distance information about a current distance between said probe and said sample; (G) a recording device for recording topography and mass spectrum measurements made during scanning of the sample with the near-field probe; (H) a plotting device for plotting said topography and mass spectrum measurements as separate x-y mappings; and (I) an imaging device for providing images of the x-y mappings.

A mass spectrometer is disclosed wherein ions are passed through an ion mobility separator and are then mass analysed by a Time of Flight mass analyzer. Multiple sets of mass spectral data are obtained which are then post-processed so that mass spectral data relating to ions having undesired charge state(s) is filtered out. The resultant mass spectrum comprises ions having a desired charge state.

The present invention discloses methods for deconvolving and converting 1D mass spectra to 2D mass spectrum in order to obtain migration time centers and total intensities of the neutral mass envelopes of 2D spectra. The present invention also discloses devices that include a preparation / separation unit coupled to a mass spectrometer unit, and a computer unit capable of deconvolving mass spectra and calculating neutral mass envelopes.

A system (20) and method are disclosed for the self-calibrating, on-line determination of size distribution f(x) and volume fraction φ of a number of particles (P) dispersed in a medium (M) by detecting one or more propagation characteristics of multiply scattered light from the particles (P). The multiply scattered light is re-emitted in response to exposure to a light source (21) configured to provide light at selected wavelengths. The determination includes calculating the isotropic scattering and absorption coefficients for the particles (P) by comparing the incident and detected light to determine a measurement corresponding to the propagation time through the scattering medium (M), and iteratively estimating the size distribution f(x) and volume fraction φ as a function of the coefficients for each of the wavelengths. An estimation approach based on an expected form of the distribution and the mass of the particles is also disclosed. Furthermore, techniques to determine a particle structure factor indicative of particle-to-particle interactions which vary with particle concentration and influence light scattering at high concentrations is disclosed.

A substrate for use in providing an ionized target comprising a structured substrate has a plurality of recesses, at least a portion of the plurality of recesses containing an initiator, the substrate being capable of having a target loaded on it. In one methods, irradiation of the substrate can cause the initiator to restructure, releasing it from the recesses and thereby desorbing and ionizing the target. The target so desorbed and ionized can be detected by mass analyzers. The mass of the targets at a given point on the surface can be recorded to provide a spatial mapping of the targets on the surface.

The invention solves the problem of artifact ghost peaks which can sometimes arise in mass spectrometers that employ a quadrupole rod set for both trapping and mass analyzing the trapped ions. The problem arises as a result of randomly distributed voltage gradients along the length of the rods. Three solutions are presented. The first approach involves improving the conduction characteristics of the rod sets. The second approach involves the application of at least one continuous axial DC field to the trapping quadrupole rod set in order to urge ions towards a pre-determined region of the trap, thereby avoiding voltage gradients. The third approach involves the application of one or more discrete axial fields to create one or more potential barriers along the axial dimension of the trap (in addition to the barriers used to initially trap the ions). These barriers prevent ions of differing voltage gradients from equilibrating with one another.

There is described an interface for delivering ions generated in an ion source into a mass analyzer in a chamber under vacuum pressure. In particular, the interface employs two consecutive ion guides operated to dissociate adduct ions formed in the ion source or high pressure regions of the interface between the ion source and the mass analyzer, thus improving the limit of detection or limit of quantitation of the mass analyzer by increasing the analyte ion current.

A new ionization source named Surface Activated Chemical Ionization (SACI) has been discovered and used to improve the sensitivity of the mass spectrometer. According to this invention the ionization chamber of a mass spectrometer is heated and contains a physical new surface to improve the ionization process. The analyte neutral molecules that are present in gas phase are ionized on this surface. The surface can be made of various materials and may also chemically modified so to bind different molecules. This new ionization source is able to generate ions with high molecular weight and low charge, an essential new key feature of the invention so to improve sensitivity and reduce noise. The new device can be especially used for the analysis of proteins, peptides and other macromolecules. The new invention overcomes some of the well known and critical limitations of the Electrospray (ESI) and Matrix Assisted Laser Desorption Ionization (MALDI) mass spectrometric techniques.

Chromatograms and mass spectra produced by an LC / MS system are analyzed by creating a two-dimensional data matrix of the spectral and chromatographic data. The two-dimensional matrix can be created by placing the spectra generated by the mass spectrometer portion of the LC / MS system in successive columns of the data matrix. In this way, the rows of the data matrix correspond to chromatographic data and the columns of the data matrix correspond to the spectra. A two-dimensional filter is specified and applied to the data matrix to enhance the ability of the system to detect peaks associated with ions. The two-dimensional filter is specified according to desired criteria. Rank-1 and rank-2 filters can be specified to improve computational efficiency. One method of applying the two-dimensional filter is through convolution of the data matrix with the two-dimensional filter to produce an output data matrix. Peaks corresponding to detected ions are identified in the output data matrix. Parameters of the peaks are determined and stored for later processing including quantitation, or simplification of chromatograms or spectra by, for example, identifying peaks associating with ions having retention times falling within a specified retention time window or having mass-to charge ratios falling within a specified mass-to-charge ratio window.

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 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.

In a tandem mass spectrometer ions are created only once and stored in an ion reservoir. A particular ion species to be analyzed is then exported from the reservoir through a mass selective ion gate without damaging the other ion species remaining in the reservoir. All subsequent analyses are conducted on these stored ions, without adding further ions so that no changes in the concentrations of the stored ion species occur. The exported ions are fragmented, and a fragment ion mass spectrum is measured in a mass analyzer, preferably in a time-of-flight mass analyzer with orthogonal ion injection. The processes of exporting a selected ion species with subsequent fragmentation and the acquisition of the fragment ion spectrum can be repeated for any number of ion species stored in the reservoir.

A method for reproducibly analyzing mass spectra from different sample sources is provided. The method deconvolutes the complex spectra by collapsing multiple peaks of different molecular mass that originate from the same molecular fragment into a single peak. The differences in molecular mass are apparent differences caused by different charge states of the fragment and / or different metal ion adducts and / or reactant products of one or more of the charge states. The deconvoluted spectrum is compared to a library of mass spectra acquired from samples of known identity to unambiguously determine the identity of one or more components of the sample undergoing analysis.

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.

A method for calibrating and analyzing data from a mass spectrometer, comprising the steps of acquiring raw profile mode data containing mass spectral responses of ions with or without isotopes; calculating theoretical isotope distributions for each of at least one calibration ion based on elemental composition; convoluting the theoretical isotope distributions with an initial peak shape function to obtain theoretical isotope profiles for each ion; constructing a peak component matrix including the theoretical isotope profiles for calibration ions as peak components; performing a regression analysis between the raw profile mode mass spectral data and the peak component matrix; and reporting the regression coefficients as the relative concentrations for each of the components. A mass spectrometry system operated in accordance with the method and a computer readable medium having program code thereon for performing the method.

A method for identifying and characterizing components of interest in complex samples includes subjecting both a sample and its control samples to chromatography / high resolution mass spectrometry analysis to detect ions of the samples. The method includes defining sections of control sample data within specified chromatographic fluctuation time and mass precision windows around each ion or each group of the same ions of question in the test sample data. The defined sections of the control sample data are examined and the maximal intensities are subtracted from respective ions in the test sample. Components of interest are determined from the resultant data of the test sample. The method can be used for identifying molecular ions and / or their fragment ions for components of interest in complex samples.

The invention covers a method for detecting ions in high resolution time-of-flight mass spectrometers which operate with secondary electron multiplier multichannel plates and in which many single spectra are acquired and added to produce a sum spectrum. The invention involves (a) using an analog digital converter (ADC) for converting electron currents from secondary electron multipliers, instead of a time-to-digital converter (TDC) which was previously used for highest possible signal resolution, (b) performing a separate rapid peak recognition procedure for the ion signals of each spectrum by a fast calculation method, thereby collecting flight time and intensity value pairs for the ion peaks, and (c) constructing a time-of-flight / intensity histogram, which is further processed as a composite time-of-flight spectrum. The invention retains the significantly higher measurement dynamics of an ADC and achieves the improved resolution capability of a TDC, but without showing the latter's known signal distortion due to dead times.

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.

A mass spectrometer and a method of mass spectrometry are disclosed wherein periodic background noise is effectively filtered out from the mass spectral data. An overall mass window is superimposed upon the mass spectral data. The overall mass window preferably comprises 21 nominal mass windows each preferably having a width of 1.0005 amu. Each nominal mass window preferably comprises 20 channels. An intensity distribution relating to all the first channels of the 21 nominal mass windows is determined. An intensity quantile is determined from the intensity distribution. The intensity quantile is taken to represent the background intensity in the first channel of the central nominal mass window. This process is repeated for the other channels so that the background intensity across the whole of the central nominal mass window is estimated and then subtracted from the raw mass spectral data comprising the central nominal mass window. The overall mass window is then preferably advanced approximately 1 amu and the process is repeated multiple times.

Releasable tag reagents for use in the detection and analysis of target molecules, particular in mass spectrometric analyses are provided. Also provided are methods of detection that employ releasable tag reagents.

An ionization method for use with mass spectrometry or ion mobility spectrometry is a small molecule compound(s) as a matrix into which is incorporated analyte. The matrix has attributes of sublimation or evaporation when placed in vacuum at or near room temperature and produces both positive and negative charges. Placing the sample into a region of sub-atmospheric pressure, the region being in fluid communication with the vacuum of the mass spectrometer or ion mobility spectrometer, produces gas-phase ions of the analyte for mass-to-charge or drift-time analysis without use of a laser, high voltage, particle bombardment, or a heated ion transfer region. This matrix and vacuum assisted ionization process can operate from atmosphere or vacuum and produces ions from large (e.g. proteins) and small molecules (e.g. drugs) with charge states similar to those observed in electrospray ionization.

The methods described herein generally relate to characterization of large analytes, such as biomolecules, by molecular mass analysis. Specifically, the methods are directed to molecular mass analysis of singly- or multiply-charged ions by selective ion filtering carried out by a digital thresholding process.

The invention discloses a method and system for increasing judgment accuracy of monoisotopic peaks. The method comprises the following steps: according to selected tandem mass spectrums, determining candidate isotopic peak clusters; according to the similarity and the strength ratio of the chromatographic outflow curves of the candidate isotopic peak clusters, determining the start and stop of the isotopic peak clusters; according to the start and stop of the isotopic peak clusters, determining the quality of the monoisotopic peaks; and judging whether the monoisotopic peaks of the tandem mass spectrums are not determined or not, if yes, returning and selecting a new tandem mass spectrum to determine a candidate isotopic peak cluster, and if not, ending.