Abstract: The present invention relates to mass spectrometry and, more particularly, to the scheduling of the steps involved in performing mass spectrometry. The present invention will be of particular benefit to types of mass spectrometry that generate large quantities of data and hence give rise to lengthy data-processing. The present invention provides a method of mass spectrometry comprising a plurality of cycles, each cycle comprising the steps of (a) preparing ions to be analysed by a mass spectrometer; (b) using a detector of the mass spectrometer to collect data from the ions prepared in step (a); and (c) processing the data collected in step (b) with processing means; wherein at least a part of step (a) and/or a part of step (b) of a cycle is performed concurrently with part (c) of a previous cycle.

Abstract: A system and method are disclosed for effectively compensating for an unbalanced or non-zero centerline radio-frequency potential in a quadrupolar ion trap, the unbalanced centerline potential created by a compensation feature that minimizes non-linear field components created by one or more ejection slots in the ion trap. The ion trap includes a centerline that passes longitudinally through a trapping volume inside of the ion trap, a pair of Y electrodes with inner Y electrode surfaces that are approximately parallel to the centerline, and a pair of X electrodes with inner X electrode surfaces that are approximately parallel to the centerline. The X electrodes have ejection slots through which trapped ions are ejected from the ion trap. A Y signal with a Y signal amplitude is coupled to both of the Y electrodes. An X signal with an X signal amplitude is coupled to both of the X electrodes.

Abstract: A system and method are disclosed for effectively compensating for an unbalanced or non-zero centerline radio-frequency potential in a quadrupolar ion trap, the unbalanced centerline potential created by a compensation feature that minimizes non-linear field components created by one or more ejection slots in the ion trap. The ion trap includes a centerline that passes longitudinally through a trapping volume inside of the ion trap, a pair of Y electrodes with inner Y electrode surfaces that are approximately parallel to the centerline, and a pair of X electrodes with inner X electrode surfaces that are approximately parallel to the centerline. The X electrodes have ejection slots through which trapped ions are ejected from the ion trap. A Y signal with a Y signal amplitude is coupled to both of the Y electrodes. An X signal with an X signal amplitude is coupled to both of the X electrodes.

Abstract: An ion trap (104) for a mass spectrometer includes an RF trapping voltage source (112) for applying an RF trapping voltage to at least one of a plurality of electrodes (102, 106, 110) of the ion trap (104) to trap at least a portion of ions in the ion trap (104); a resonance excitation voltage source (114) for applying a resonance excitation voltage pulse to the electrodes(102, 106, 110) to cause at least a portion of a selected set of ions to undergo collisions and break into ion fragments; and a computer (116) for controlling the RF trapping voltage source (112) to reduce the RF trapping voltage after a predetermined delay period following termination of the resonance excitation voltage pulse to a second amplitude for retaining a low mass ion fragments in the ion trap (104) for later analysis.

Abstract: An ion source is disclosed for forming multiply-charged analyte ions from a solid sample. A beam of pulsed radiation is directed onto a portion of the sample to desorb analyte molecules. A retaining structure holding a solvent volume is positioned proximate the sample. Desorbed analyte molecules contact a free surface of the solvent and pass into solution. The solution is then conveyed through an outlet passageway to an electrospray apparatus, which introduces a spray of charged solvent droplets into an ionization chamber.

Abstract: A device for transporting and focusing ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from a plurality of longitudinally spaced apart electrodes to which oscillatory (e.g., radio-frequency) voltages are applied. In order to create a tapered field that focuses ions to a narrow beam near the device exit, the inter-electrode spacing or the oscillatory voltage amplitude is increased in the direction of ion travel.

Abstract: A method is disclosed for data-dependent neutral loss analysis of biomolecules and other materials in a hybrid mass spectrometer. Candidate product ions are selected by identifying peaks in a MS/MS spectrum acquired in a first mass analyzer that exhibit a specified nominal neutral loss value, which may be representative of the mass of a peptide modification, such as phosphate. High mass accuracy MS and MS/MS spectra acquired at a second mass analyzer, such as an FTICR or Orbitrap, are processed to determine if the mass difference between a candidate product ion and its corresponding precursor matches an accurate neutral loss value. In one embodiment, MS3 analysis is performed only on the candidate product ions that satisfy the accurate mass neutral loss value test.

Abstract: A variable duty cycle ion source assembly is coupled to a continuous beam mass spectrometer. The duty cycle can be adjusted based on previous scan data or real time sampling of ion intensities during mass analysis. This provides the ability to control the total number of ions formed, mass analyzed and detected for each ion mass of interest. The frequency of the ion source can be sufficiently high (kHz range) so as to maintain accurate peak centroiding. The ion source assembly can be used for both electron ionization (EI) or chemical ionization (CI) modes of operation.

Abstract: 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.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. Such ion storage devices are often used to store ions prior to ejection to a subsequent mass analyzer. The RF field is usually collapsed prior to ion ejection. The present invention provides a RF power supply comprising: a RF signal supply, a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device, and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: In a spectroscopic microscope, a video image of a specimen is analyzed to identify regions having different appearances, and thus presumptively different properties. The sizes and locations of the identified regions are then used to position the specimen to align each region with an aperture, and to set the aperture to a size appropriate for collecting a spectrum from the region in question. The spectra can then be analyzed to identify the substances present within each region of the specimen. Information on the identified substances can then be presented to the user along with the image of the specimen.

Abstract: An ion guide having a plurality of spheroidal or similarly shaped electrodes is disclosed. The electrodes are arranged in pairs about a central ion flow axis, and an RF voltage is applied in a prescribed phase relation to create an electric field that focuses and radially confines an ion beam. A defocusing effect associated with the electrode shape may be reduced by placement of a separate skirt electrode immediately downstream in the ion path, or by forming the electrodes in a composite structure, whereby the trailing portion of the electrode is fabricated from or coated with an insulative material.

Abstract: A method of generating a mass spectrum from an FTMS is disclosed. A first quantity of ions from a source, having a first m/z range, is captured and detected in the FTMS measurement cell to produce a first output. A second quantity of ions, having a second m/z range which at least partially does not overlap with the first m/z range, is then captured and detected so as to produce a second output. The two outputs are then combined using a processor so as to “stitch” together the outputs, which may be FTMS transients or may first be Fourier Transformed into the frequency mass domain, into a composite output from which a composite mass spectrum covering the full range of m/z ratios included by the first and second ranges can be produced.

Abstract: In a spectrometer, preferably in a spectrometric microscope, light from a specimen is collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. A focal plane is provided between the collector objective element and the camera element, and one or more aperture arrays may be situated in the focal plane to restrict the detector's field of view of the specimen to the areas within the apertures. By utilizing aperture arrays with apertures of different sizes and shapes, the spatial resolution of the spectrometer readings may be varied without the need to vary the optics of the spectrometer. As a result, if the optics are optimized to minimize vignetting, spatial resolution may be varied without adverse increases in vignetting.

Abstract: A spectrometer generates Vibrational Circular Dichroism (VCD) measurements having an exceedingly high signal-to-noise ratio, as well as a greater wavelength range over which measurements may be accurately provided. This is achieved by utilizing reflective optics (preferably solely reflective optics, i.e., no refractive elements) to supply a concentrated and collimated input light beam to a sample within a sample cell, and similarly collecting the light output from the sample cell via reflective optics for supply to a detector.

Abstract: A method and apparatus are provided for operating a linear ion trap. A linear ion trap configuration is provided that allows for increased versatility in functions compared to a conventional three-sectioned linear ion trap. In operation, the linear ion trap provides multiple segments, the segments spatially partitioning an initial ion population into at least a first and a second ion population, and enabling the ions corresponding to the first ion population to be expelled from the linear ion trap substantially simultaneously with the ions corresponding to the second ion population. Each segment is effectively independent and ions corresponding to the first ion population are able to be manipulated independently from ions corresponding to ions corresponding to the second ion population; the ions having been generated by an ion source under the same conditions.

Abstract: An analytical instrument is disclosed having both XRF and spark emission spectroscopy capabilities. In a particularly advantageous embodiment, a field portable XRF device is removably coupled to the instrument by means of a docking station. A first surface of the sample is irradiated with an X-ray beam, and the X-ray radiation fluorescently emitted from the sample is detected and analyzed to acquire elemental composition data. The instrument is further provided with a spark source located proximal a second surface of the sample and a detector for sensing the radiation emitted from the spark-excited material. The combined instrument enables the acquisition of complementary elemental composition data by XRF and spark emission spectroscopy without having to transport a sample between separate instruments.

Abstract: A mass spectrometer 10 comprises an ion source 12 which generates nebulized ions which enter an ion cooler 20 via an ion source block 16. Ions within a window of m/z of interest are extracted via a quadrupole mass filter 24 and passed to a linear trap 30. Ions are trapped in a potential well in the linear trap 30 and are bunched at the bottom of the potential well adjacent an exit segment 50. Ions are gated out of the linear trap 30 into an electrostatic ion trap 130 and are detected by a secondary electron multiplier 10. By bunching the ions in the linear trap 30 prior to ejection, and by focussing the ions in time of flight (TOF) upon the entrance of the electrostatic trap 130, the ions arrive at the electrostatic trap 130 as a convolution of short, energetic packets of similar m/z. Such packets are particularly suited to an electrostatic trap because the FWHM of each packet's TOF distribution is less than the period of oscillation of those ions in the electrostatic trap.

Abstract: A method of obtaining a mass spectrum of elements in a sample is disclosed. Sample precursor ions having a mass to charge ratio M/Z are generated, and fragmented at a dissociation site, so as to produce fragment ions of mass to charge ratio m/z. The fragment ions are guided into an ion trap of the electrostatic or “Orbitrap” type, the fragment ions entering the trap in groups dependent upon the precursor ions M/Z. The mass to charge ratio of each group is determined from the axial movement of ions in the trap. The electric field in the trap is distorted. Ions of the same m/z, that are derived from different pre-cursor ions, are then separated, because the electric field distortion causes the axial movement to become dependent upon factors other than m/z alone.

Abstract: A MALDI mass spectrometer includes a radiation source, such as a gas or solid state laser, that emits a beam of radiation (typically in the UV or IR wavelengths) directed along the central axis of a linear ion trap in which analyte ions and matrix cluster ions are confined. The radiation beam has a wavelength that is strongly absorbed by the matrix cluster ions. The absorption of radiation by the matrix cluster ions produces dissociation of the matrix cluster ion into fragments having mass-to-charge ratios that lie below a mass-to-charge ratio range of interest. Thus, chemical noise associated with matrix cluster ions is reduced or eliminated.