Abstract: An ion guide with two or more ion focusing elements and a gas channeling sleeve is described. An ion transport space within the gas channeling sleeve is in fluid communication with a pumping port. A suction device is used to suction gas out of the ion transport space through the pumping port establishing a gas flow. Ions in the ion transport space are transported from an ion entry end to an ion exit end of the ion guide by the gas flow. Several examples include a multipole ion guide in which rods are used as ion focusing elements. The gas channeling sleeve is fitted about the rods. In another example, toroidal or ring shaped ion focusing elements are used as ion focusing elements. In another example, a set of ion focusing rings are mounted between insulators to form a cylinder with a gas impermeable side wall. The cylinder is itself used as the gas channeling sleeve.

Abstract: A sample analysis system incorporates an ion removal mechanism for removing residual ions from the sample analysis system. The ion removal mechanism can be included in an ion optics assembly, which connects an ion mobility filter to a mass analyzer. A sample to be analyzed by the sample analysis system may be entered into an ion mobility filter. The ion mobility filter filters the ions of the sample and passes the filtered group of ions to the ion optics assembly. The ion optics assembly transports the filtered group of ions to a mass analyzer where some or all of the ions in the group are detected. The ion removal mechanism then removes all or substantially all residual ions from the ion optics that were left over from the first filtered group before a second filtered group is passed through.

Abstract: A method for introducing samples through a boundary member partially defining a chamber at an entrance point coaxial to a sampling inlet of a mass spectrometer is described. Field-free conditions can be established in at least one region of the chamber. The sample can be introduced adjacent to the sampling inlet, and introducing at least a second sample can be introduced through at least one other entrance point in the chamber not adjacent to the sampling inlet. An apparatus having a sampling inlet and a boundary member partially defining a chamber is also described. Field-free conditions can be established in at least one region of the chamber, and there can be a first aperture in the boundary member through which a source emits sample. Related devices, uses and mass spectrometers are also described.

Abstract: An apparatus and method for performing mass spectroscopy uses an ion interface to provide the function of removing undesirable particulates from an ion stream from an atmospheric pressure ion source, such as an electrospray source or a MALDI source, before the ion stream enters a vacuum chamber containing the mass spectrometer. The ion interface includes an entrance cell with a bore that may be heated for desolvating charged droplets when the ion source is an electrospray source, and a particle discrimination cell with a bore disposed downstream of the bore of the entrance cell and before an aperture leading to the vacuum chamber. The particle discrimination cell creates gas dynamic and electric field conditions that enables separation of undesirable charged particulates from the ion stream.

Abstract: A laser desorption ion source provides enhanced ion sampling efficiency and measurement sensitivity by using one or more ion guides to effectively capture ions in a plume emitted from the ion target and guide the ions through an aperture into a downstream vacuum chamber. In one configuration using two RF multipole ion guides, a first RF multipole ion guide disposed next to the ion target is selected to be sufficiently large to capture a substantial portion of the plume, while the second RF multipole ion guide disposed between the first multipole ion guide and the aperture has a smaller dimension to assist focusing of ions into the aperture. The first RF multipole ion guides the ions in the plume into the second RF multipole ion guide, which then focuses the ions so that they pass through the aperture into the downstream vacuum chamber.

Abstract: A mass spectrometry quantitation technique enables high-throughput quantitation of small molecules using a laser-desorption (e.g., MALDI) ion source coupled to a triple-quadrupole mass analyzer. The ions generated from the ion source are collisionally damped/cooled, and then quantitatively analyzed using the triple-quadrupole analyzer operated in the multiple-reaction-monitoring (MRM) mode. Significantly improved measurement throughput is obtained by applying the laser to each sample spot on the target for an irradiation duration significantly shorter than the time required to deplete the sample material in the sample spot. The irradiation duration may be set based on a determination of the MRM peak broadening caused by the ion optics.

Abstract: In a mass spectrometer, ions from an ion source pass through an inlet aperture into a vacuum chamber for transmitting prior to mass analysis by the mass analyzer. The configuration of the inlet aperture forms a sonic orifice or sonic nozzle and with a predetermined vacuum chamber pressure, a supersonic free jet expansion is created in the vacuum chamber that entrains the ions within the barrel shock and Mach disc. Once formed, at least one ion guide with a predetermined cross-section to essentially radially confine the supersonic free jet expansion can focus the ions for transmission through the vacuum chamber. This effectively improves the ion transmission between the ion source and the mass analyzer.

Abstract: An apparatus and method for performing mass spectroscopy uses an ion interface to provide the function of removing undesirable particulates from an ion stream from an atmospheric pressure ion source, such as an electrospray source or a MALDI source, before the ion stream enters a vacuum chamber containing the mass spectrometer. The ion interface includes an entrance cell with a bore that may be heated for desolvating charged droplets when the ion source is an electrospray source, and a particle discrimination cell with a bore disposed downstream of the bore of the entrance cell and before an aperture leading to the vacuum chamber. The particle discrimination cell creates gas dynamic and electric field conditions that enables separation of undesirable charged particulates from the ion stream.

Abstract: A mass spectrometry quantitation technique enables high-throughput quantitation of small molecules using a laser-desorption (e.g., MALDI) ion source coupled to a triple-quadrupole mass analyzer. The ions generated from the ion source are collisionally damped/cooled, and then quantitatively analyzed using the triple-quadrupole analyzer operated in the multiple-reaction-monitoring (MRM) mode. Significantly improved measurement sensitivity is obtained by applying laser pulses to the ion source at a high pulse rate of about 500 Hz or higher. This allows the data acquisition to be performed rapidly, and the speed of about one second for each sample point on the ion source target has been achieved.

Abstract: An apparatus and method for performing mass spectroscopy uses an ion interface to provide the function of removing undesirable particulates from an ion stream from an atmospheric pressure ion source, such as an electrospray source or a MALDI source, before the ion stream enters a vacuum chamber containing the mass spectrometer. The ion interface includes an entrance cell with a bore that may be heated for desolvating charged droplets when the ion source is an electrospray source, and a particle discrimination cell with a bore disposed downstream of the bore of the entrance cell and before an aperture leading to the vacuum chamber. The particle discrimination cell creates gas dynamic and electric field conditions that enables separation of undesirable charged particulates from the ion stream.

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 mass spectrometry quantitation technique enables high-throughput quantitation of small molecules using a laser-desorption (e.g., MALDI) ion source coupled to a triple-quadrupole mass analyzer. The ions generated from the ion source are collisionally damped/cooled, and then quantitatively analyzed using the triple-quadrupole analyzer operated in the multiple-reaction-monitoring (MRM) mode. Significantly improved measurement sensitivity is obtained by applying laser pulses to the ion source at a high pulse rate of about 500 Hz or higher. This allows the data acquisition to be performed rapidly, and the speed of about one second for each sample point on the ion source target has been achieved.

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: An interface apparatus, for coupling 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: An interface member plate is provided for use in a mass spectrometer system. It includes an orifice and a desolvation chamber which can be generally cylindrical and elongate. Moreover, the desolvation chamber can be heated to encourage desolvation of any remaining solvant. The orifice largely determines flow into low pressure downstream sections containing sections of the mass spectrometer. The desolvation chamber has a larger cross-section and its characteristic parameters can be set independently of the parameters of the orifice. The interface member can be provided directly downstream from an ion source, or separating an upstream curtain gas chamber from the low pressure mass analyzing sections of the mass spectrometer.

Abstract: A method of analyzing a protein, namely determining the amino acid sequence of a protein is described. Trypsin is added to a protein to form a liquid phase mixture of trypsin and the protein. The disulfide linkages of the protein may be reduced and the resulting sulfhydryl groups alkylated either before or after the addition of trypsin. The trypsin is allowed to digest the protein long enough to cleave protein into tryptic fragments. A portion of the digested mixture is ionized by ion evaporation to produce gas phase ions of the tryptic fragments, the gas phase ions being predominantly doubly charged with one charge at each end of the doubly charged ions. The gas phase ions of the tryptic fragments are analyzed by sequentially selecting therefrom ions of a desired mass to charge ratio in a first mass analyzer. The selected ions are fragmented by collision in a second mass analyzer to produce daughter ions, and the daughter ions are then analyzed in a third mass analyzer.

Abstract: A method of analyzing a protein, namely determining the amino acid sequence of a protein is described. Trypsin is added to a protein to form a liquid phase mixture of trypsin and the protein. The disulfide linkages of the protein may be reduced and the resulting sulfhydryl groups alkylated either before or after the addition of trypsin. The trypsin is allowed to digest the protein long enough to cleave protein into tryptic fragments. A portion of the digested mixture is ionized by ion evaporation to produce gas phase ions of the tryptic fragments, the gas phase ions being predominantly doubly charged with one charge at each end of the doubly charged ions. The gas phase ions of the tryptic fragments are analyzed by sequentially selecting therefrom ions of a desired mass to charge ratio in a first mass analyzer. The selected ions are fragmented by collision in a second mass analyzer to produce daughter ions, and the daughter ions are then analyzed in a third mass analyzer.

Abstract: A method of analyzing a protein, namely determining the amino acid sequence of a protein is described. Trypsin is added to a protein to form a liquid phase mixture of trypsin and the protein. The disulfide linkages of the protein may be reduced and the resulting sulfhydryl groups alkylated either before or after the addition of trypsin. The trypsin is allowed to digest the protein long enough to cleave protein into tryptic fragments. A portion of the digested mixture is ionized by ion evaporation to produce gas phase ions of the tryptic fragments, the gas phase ions being predominantly doubly charged with one charge at each end of the doubly charged ions. The gas phase ions of the tryptic fragments are analyzed by sequentially selecting therefrom ions of a desired mass to charge ratio in a first mass analyzer. The selected ions are fragmented by collision in a second mass analyzer to produce daughter ions, and the daughter ions are then analyzed in a third mass analyzer.

Abstract: Liquid from a liquid chromatograph or other sample source, preferably assisted by a high velocity coaxial gas jet, is sprayed through a capillary tube producing a flow in a first direction of charged droplets. A flow of heated gas, in a second direction different from the first direction, intersects the droplet flow at a region upstream of an orifice. The flows mix turbulently, with the second flow helping to evaporate the droplets to produce ions and helping to move the evaporating droplets toward the orifice, providing a focusing effect. Ions are drawn through the orifice into a mass analyzer and analyzed. Alternatively the flows of liquid and heating gas can be directed toward each other and at right angles to the axis through the orifice, and the inhaling effect of the orifice can be used to draw droplets toward it, or a third gas flow can be used for this purpose. The heated intersecting gas flow typically provides an increase in sensitivity (ion counts per second) of between 10 and 100 times.