Abstract: A method and apparatus for the analysis of a narrow range of fragment ions by application of a notched broadband waveform during ion accumulation within a quadrupole collision cell operated as a linear ion trap. The fragment ions are formed via the axial acceleration and collision activated dissociation of mass resolved precursor ions. A narrow band of frequencies is purposefully omitted from the spectrum, so that the secular frequency of a particular fragment ion will fall within this notch of absent frequencies and as a result will not experience resonant excitation and are retained in the linear ion trap. Simultaneously, all other ions are lost either through neutralization when they strike electrodes or through (additional) collision activated dissociation. Accordingly, a particular mass or range of masses, whose secular frequencies fall within the notch of absent frequencies in the notched broadband waveform, may be selectively accumulated during the collision activated dissociation event.

Abstract: A mass spectrometer has an ion source for producing sample ions. The ions pass through an ion interface, to a reaction/collision cell section. An inn-neutral decoupling device is provided between the ion interface and the reaction/collision cell section, to provide substantial separation between ions and neutral particles, whereby only ions pass on to the reaction/collision cell section. The supersonic jet entering the spectrometer can have sufficient energy to cause the plasma gases, such as argon, to overcome the pressure differential between the reaction/collision cell and an upstream section of the spectrometer so as to penetrate into the reaction/collision cell; the decoupling device prevents this. The decoupling device can have offset apertures provided by plates or rods or other comparable arrangements, or can comprise a quadrupolar electrostatic deflector, an electrostatic sector deflector or a magnetic sector deflector.

Abstract: This invention relates to radioactively coated devices, preferably radioactively coated medical devices. These coated devices are characterized as having a low rate of leaching of the radioisotope from the surface of the coated device and a uniform radioactive coating, and are therefore suitable for use within biological systems. Methods for coating a device with a radioisotope comprising are also disclosed. One method comprises immersing the device within a solution containing a &Ugr;, &bgr;+, &agr;, &bgr;− or &egr; (electron capture) emitting radioisotope, then exposing the immersed substrate to tuned vibrational cavitation to produce a coated substrate. A second method involves coating a substrate using electroless plating, and yet a third method involves the use of electroplating a radioisotope onto a substrate of interest. With these methods, the coating procedures are followed by baking the coated substrate at a temperature below the recrystallization temperature of the substrate.

Abstract: An interface apparatus, for coupling a plurality of ion source to a mass spectrometer has a plurality of ion sources for generating a plurality of ion beams. An inlet device for passing ion beams into the mass spectrometer is provided as is a device or mechanism for selecting one of the ion beams for passage through into the mass spectrometer and for blocking the other ion beams. An outlet provides a connection to a mass spectrometer. A corresponding method is provided.

Abstract: Ions for analysis are formed from a liquid sample comprising an analyte in a solvent liquid by directing the liquid sample through a capillary tube having a free end so as to form a first flow comprising a spray of droplets of the liquid sample, to promote vaporization of the solvent liquid. An orifice member is spaced from the free-end of the capillary tube and has an orifice therein. An electric field is generated between the free-end of the capillary and the orifice member, thereby causing the droplets to be charged, and the first flow is directed in a first direction along the axis of the capillary tube. Two gas sources, or an arc jet of gas, provide second and third flows, of a gas, and include heaters for heating the second and third flows.

Abstract: A microfluidic rotary valve and methods of manufacturing same are disclosed. The rotary valve includes a stator chip having at least one inlet and at least one outlet. The rotary valve also includes a rotor having at least one rotor channel in sealed engagement with the stator chip. The rotor rotates between valve positions preventing and allowing fluid communication between the inlets and outlets by way of the rotor channels and according to the design of the inlets, outlets and rotor channels. The stator chip includes a first planar substrate having a contact face and a second planar substrate having a contact face bonded to the contact face of the first planar substrate. The first planar substrate defines a first portion of the inlet and outlet, and the second planar substrate defines a second portion of the inlet and outlet.

Abstract: A hybrid mass spectrometer comprises an ion mobility (IMS) section and a mass analysis section that analyses ions based on mass-to-charge ratios. In the IMS section, a DC potential gradient is established and a drift gas provided, so as to separate ions based on varying ion mobilities. Additionally, at least a downstream portion of the IMS section includes a rod set focusing ions along the axis, this prevents loss of ions and gives good transfer of ions into-a-mass analysis section, which can be a time-of-flight mass analyzer or an analyzer including a quadrupole rod set. A collision cell and mass analyzer can be provided between the two sections for MS/MS analysis. The IMS section then provides better utilization of an available sample; as each group of ions is elected from the IMS section, one ion can be mass selected as a precursor, for subsequent fragmentation/reaction and subsequent mass analysis of the product ions.

Abstract: A method of analyzing a substance comprises ionizing the substance to form a string of ions. The ions are then subject to a first mass analysis step. In one embodiment, the ions are accelerated into a collision cell in known manner to form primary fragment ions. These primary fragment ions are then accelerated into a downstream mass analyzer, to promote secondary fragmentation. In another embodiment of the invention, ions are passed through the collision cell, without fragmentation, and then accelerated from the collision cell into a low pressure section, which may be a mass analyzer or a rod set for collecting and collimating ions. This is done under conditions that promote fragmentation. The operating conditions of the low pressure section can be such as to promote collection or retention of ions depending upon their mass, and more specifically to reject low mass ions.

Abstract: A method and apparatus for operating a mass spectrometer system, having a processing section, provides for the application of both an axial field and periodic application of a flush pulse to the processing section. This gives a reproducible output ion signal from the processing section that is very responsive to changes in operating conditions in the processing section. The mass spectrometer system can comprise: a collision/reaction cell having an input and an output; and a set of elongated rods extending between said input and output, said elongated rods spatially arranged. Separate auxiliary electrodes can be provided to generate the axial field. The invention has particular applicability to ICP-MS, where strong ion currents can result in a collision cell taking some time to reach equilibrium when the operating condition is changed.

Abstract: An improved method of operating a mass spectrometer having a linear ion trap wherein ions are axially ejected from the trap to a detector or subsequent mass analysis stage. The DC barrier field produced at the exit lens of the trap is scanned in conjunction with the scanning of other fields used to energize ions of select mass-to-charge ratios past the barrier field/exit lens. The technique can maximize the resolution obtainable from axial ejection over a wide mass range.

Abstract: A method of improving the signal to noise ratio of an ion beam, utilizing a tandem mass spectrometer comprising two mass filters separated by a collision cell. The first mass filter is operated in a resolving mode such that only a narrow mass-to-charge range of precursor ions are stable and accelerated towards the collision cell which contains neutral gas to promote collisional activation and subsequent fragmentation of unwanted fragile ions while minimizing fragmentation of desired analyte ions. The second mass filter is scanned synchronously with the first mass filter such that only ions that do not fragment are recorded by the ion detector. Thus, analyte ions that have fragmentation values higher than unwanted background ions are preferentially detected thereby increasing the signal-to-noise ratio of the ion beam.

Abstract: A mass spectrometer has an ion source for producing sample ions. The ions pass through an ion interface, to a reaction/collision cell section. An ion-neutral decoupling device is provided between the ion interface and the reaction/collision cell section, to provide substantial separation between ions and neutral particles. The supersonic jet entering the spectrometer can have sufficient energy to cause the plasma gases, such as argon, to overcome the pressure differential between the reaction/collision cell and an upstream section of the spectrometer so as to penetrate into the reaction/collision cell; the decoupling device prevents this. The decoupling device can have offset apertures provided by plates or rods or other comparable arrangements, or can comprise a quadrupolar electrostatic deflector, an electrostatic sector deflector or a magnetic sector deflector.

Abstract: To control movement of ions in a mass spectrometer, an ion guide has means for generating an electric field along the ion guide, and also provision for generating a gas flow along the ion guide. This then subjects ions to forces, an electric field force and a drag force. These can be set to control motion of ions as desired. The ion guide can form part of ion mobility section, in which case the forces can be set to enhance separation of ions and to control elution of different groups of ions from the ion mobility spectrometer for subsequent analysis. Eluted ions can be selected to further analysis, e.g., collisional fragmentation followed by mass analysis in a time-of-flight instrument. The technique is applicable to other elements of a mass spectrometer; for example, the fragmentation cell can be configured so that ions therein are subjected to both drag forces and electric forces, to control movement thereof.

Abstract: A method of setting a fill time for a mass spectrometer including a linear ion is provided. The mass spectrometer is operated first in a transmission mode and ions are supplied to the mass spectrometer. Ions are detected as they pass through at least part of the mass spectrometer in a preset time period, to determine the ion current. From a desired maximum charge density for the ion trap and the ion current, a fill time for the ion trap is determined. The mass spectrometer is operated in a trapping mode to trap ions in the ion trap, and the ion trap is filled for the fill time, as just determined. This utilizes the ion trap to its maximum, while avoiding problems due to overfilling the trap, causing space charge effects.

Abstract: In a mass spectrometry system, a method of operating a processing section, for example a collision cell, is provided. The method is based on the realization that some interfering ions after collision will have significantly lower kinetic energy than desired analyte ions. These interfering ions can be ions originating from the source, or product ions formed by reaction with gas particles, or ions produced by other processes within the cell. Significantly, these interfering ions can have lower kinetic energies, as compared to desired analyte ions, but this energy differential disappears, or is much reduced, at the exit of the collision cell, rendering post-cell energy discrimination less effective. The invention provides a field within the cell to discriminate against the interfering ions based on their lower kinetic energy.

Abstract: A computer-based method for reducing chemical background in acquired electrospray and nanospray mass spectra, which comprises the steps of pre-processing an acquired mass spectrum, transforming the pre-processed mass spectrum into the frequency domain, reducing peaks in the transformed mass spectrum at calculated frequencies, applying an inverse transformation to the mass spectrum represented in the frequency domain, further processing and subsequent output of a mass spectrum with chemical background reduced. The invention enables rapid, automated generation of mass spectra with the component attributed to chemical background reduced, thereby allowing the mass spectrum to be analyzed more easily and effectively. The invention also generates mass spectra with improved signal-to-noise ratio and sample mass accuracy.

Abstract: A method and apparatus for the analysis of a narrow range of fragment ions by application of a notched broadband waveform during ion accumulation within a quadrupole collision cell operated as a linear ion trap. The fragment ions are formed via the axial acceleration and collision activated dissociation of mass resolved precursor ions. A narrow band of frequencies is purposefully omitted from the spectrum, so that the secular frequency of a particular fragment ion will fall within this notch of absent frequencies and as a result will not experience resonant excitation and are retained in the linear ion trap. Simultaneously, all other ions are lost either through neutralization when they strike electrodes or through (additional) collision activated dissociation. Accordingly, a particular mass or range of masses, whose secular frequencies fall within the notch of absent frequencies in the notched broadband waveform, may be selectively accumulated during the collision activated dissociation event.

Abstract: A high intensity ion source for a mass spectrometer is provided having system dimensions and parameters which cause the Taylor cone of a liquid charge stream to pass through an aperture in a lens into a low pressure chamber without substantially desolvating. A capillary tube having an outlet diameter on the order of 50 micrometers is located in an ion source chamber which is maintained at close to atmospheric pressure. The outlet of the capillary tube is positioned at a distance on the order of 250 micrometers from the aperture of the lens. The low pressure chamber is maintained at a pressure on the order of 13 pascals. With a suitable applied field, a Taylor cone ion stream is formed and passes through the aperature in the lens into a low pressure chamber without substantially desolvating. Substantial desolvation of the liquid charge stream is accomplished through the application of heating techniques within the low pressure chamber.

Abstract: This invention comprises an apparatus and method for generating sample ions from sample molecules in which a mixture of a sample and a matrix are vaporized by a laser beam and subsequently ionized by reagent corona ions. The decoupling of the vaporization and ionization steps allows each process to be separately optimized. The vaporization and ionization steps can be done in a sub-atmospheric pressure region. Alternatively, the vaporization and ionization steps can be done in a higher pressure region. In addition, the reagent corona ions can be generated in a vacuum chamber or a chamber at atmospheric pressure. Alternatively, the reagent ions can be generated in a sub-atmospheric region while the laser desorption occurs in an atmospheric region.

Abstract: There is provided a method of, and apparatus for, analyzing a sample of an analyte provided as a sample solution comprising a solvent and an analyte. A dopant is provided, either separately or as the solvent of the sample solution. The sample solution is formed into a spray, for example in a nebulizer, and the solvent evaporated. The sample stream is irradiated in a region at atmospheric pressure, either in the liquid state prior to formation of a spray, or in the liquid state after formation of a droplet spray, or in the vapour state after evaporation of the sprayed droplets, to ionize the dopant. Then, subsequent collisions between the ionized dopant and the analyte, either directly or indirectly, result in ionization of the analyte. Analyte ions are passed from the atmospheric pressure ionization region into a mass analyzer for mass analysis. This technique has been found to give much enhanced ionization for some substances, as compared to atmospheric pressure chemical ionization.