Abstract: A cross-flow ion mobility spectrometer consists of two parallel plates defining a volume between them. Analyte ions flow along an axis from an entrance end to an exit end through the volume. An RF confining field tends to guide ions along the axis. An analytical gas flow is established orthogonal to the axis. A DC electrostatic analytical field is oriented in opposition to the analytical gas flow such that the “drag force” on ions of the selected mobility due to the analytical gas flow is balanced by the force on the ions due to the electrostatic analytical field. The selected ions are thereby able to follow a stable path to the exit end of the cross-flow mobility analyzer. However, the force on ions of other than the selected mobility is unbalanced and these ions are deflected and lost.

Abstract: An abridged multipole structure for the transport and selection of ions along a central axis in a vacuum system is constructed from a plurality of rectilinear electrode structures, each having a substantially planar face with a first dimension and a second dimension perpendicular to the first dimension. When a voltage is applied across the second dimension, an electrical potential is produced at the planar face whose amplitude is a linear function of position along the second dimension. Two electrode structures can be arranged parallel to each other with the first dimension extending along the central axis or more electrodes structures can be arranged to form multipole structures with various polygonal cross sections.

Abstract: An improved trap-TOF mass spectrometer has a set of electrodes arranged to produce both a quadrupolar RF confining field and a substantially homogeneous dipole field. In operation, ions are first confined by the RF field and then, at a selected time, the RF confining field is discontinued and the dipole field is used to accelerate the ions so as to initiate a TOF MS analysis. The apparatus of the present invention may be used alone or in conjunction with other analyzers to produce mass spectra from analyte ions.

Abstract: Embodiments of the present disclosure provide methods of controlling an ion detector to minimize false peaks when utilizing extended dynamic range techniques. In one exemplary example, methods of controlling an ion detector are provided, comprising the steps of: determining an electronic baseline signal of the ion detector; receiving one or more ion input signals at the ion detector; comparing the ion input signal to the electronic baseline signal; and multiplying the ion input signal by a selected compensation factor when the ion input signal exceeds the electronic baseline signal.

Abstract: An abridged multipole structure for the transport and selection of ions along a central axis in a vacuum system is constructed from a plurality of rectilinear electrode structures, each having a substantially planar face with a first dimension and a second dimension perpendicular to the first dimension. When a voltage is applied across the second dimension, an electrical potential is produced at the planar face whose amplitude is a linear function of position along the second dimension. Two electrode structures can be arranged parallel to each other with the first dimension extending along the central axis or more electrodes structures can be arranged to form multipole structures with various polygonal cross sections. Additional embodiments can act as linear ion traps or Paul ion traps.

Abstract: An atmospheric pressure ion source, employing the principle of electrospray ionization, chemical ionization, or photo-ionization, comprises a spray probe for spraying a liquid into an ionization chamber and has an exhaust port through which residual spray mist and waste gas, such as evaporated solvent, are extracted. The ion source further comprises an exhaust system comprising a conduit which is connected to the exhaust port. The conduit has a transition from a first cross-section to a second cross section at a point downstream of the exhaust port wherein the second cross section is reduced in relation to the first cross section. Gas is injected via a gas injector into the conduit in a region of the transition to create a low pressure region that removes unwanted material from the chamber.

Abstract: A cross-flow ion mobility spectrometer consists of two parallel plates defining a volume between them. Analyte ions flow along an axis from an entrance end to an exit end through the volume. An RF confining field tends to guide ions along the axis. An analytical gas flow is established orthogonal to the axis. A DC electrostatic analytical field is oriented in opposition to the analytical gas flow such that the “drag force” on ions of the selected mobility due to the analytical gas flow is balanced by the force on the ions due to the electrostatic analytical field. The selected ions are thereby able to follow a stable path to the exit end of the cross-flow mobility analyzer. However, the force on ions of other than the selected mobility is unbalanced and these ions are deflected and lost.

Abstract: An ion guide that transports ions from an ion source at generally a high-pressure level to a mass analyzer at generally a low-pressure level has a plurality of identical electrodes fabricated with protruding elements that forming an ion tunnel or an ion funnel, when the electrodes are assembled around a common longitudinal axis. The protruding elements allow the generation of the radio frequency field necessary to radially confine ions. Each electrode may be machined from a solid block of conductive material, such as metal. The disclosed arrangement greatly simplifies the manufacturing process, reducing cost, and improving robustness and reliability of the ion guide itself.

Abstract: An assembly for use in an electrospray ion source includes a capillary for guiding a flow of liquid generally containing analyte(s) of interest, which is to be electrosprayed into an ionization chamber, a first tube at least partially encasing the capillary such that a first conduit for guiding a first heatable gas is created proximate the capillary and a hollow member that has an internal evacuated space and is located at the outer circumference of the capillary such that heat transfer from the first heatable gas flowing proximate the capillary to the liquid in the capillary is impeded. The assembly provides a simple and lean/compact way of preventing excessive heat transfer to the liquid in the capillary of an electrospray ion source.

Abstract: In an ion mobility spectrometer in which a gas flows through a gas-tight tube with a radially quadrupolar RF field therein and blows ions against a DC electric field barrier, a mobility scan with a mobility scale that is linear in time is obtained by holding the height of the DC electric field barrier constant while changing the pressure and temperature conditions of the flowing gas. Alternatively, the mobility scan is performed by holding the pressure and temperature conditions of the flowing gas constant and reducing the height of the DC electric field barrier non-linearly with respect to time.

Abstract: A transfer line for conveying the column effluent from a gas chromatograph to an ion source of a mass spectrometer has a transfer line body and a mechanism for moving the transfer line body either towards or away from the mass spectrometer. A gas seal between the housing of the mass spectrometer and the transfer line body prevents vacuum leak when the transfer line body is moved. In one embodiment, the transfer line body outer periphery is threaded and a hand wheel engages the transfer line body threads via complementary threads in order to move the body. When the transfer line is moved towards the mass spectrometer, the body presses an ion source, which is not rigidly fixed to the housing of the mass spectrometer, into a recess seat of the housing, and aligns the ion source in an operating position.

Abstract: In one embodiment, a mass spectrometer includes an RF drive circuit for generating RF signals, a quadrupole mass filter, and a fixed connection assembly for delivering RF signals from the RF drive circuit to the quadrupole mass filter, the fixed connection assembly representing the entire delivery path of RF signals from the RF drive circuit to the quadrupole mass filter. By avoiding flexible components such as a freestanding wires or flexible circuit boards, the need for retuning when parts are removed or disturbed for testing or servicing is reduced, and a modular instrument in which components and connections are standardized and therefore interchangeable is realized.

Abstract: A cross-flow ion mobility spectrometer consists of two parallel plates defining a volume between them. Analyte ions flow along an axis from an entrance end to an exit end through the volume. An RF confining field tends to guide ions along the axis. An analytical gas flow is established orthogonal to the axis. A DC electrostatic analytical field is oriented in opposition to the analytical gas flow such that the “drag force” on ions of the selected mobility due to the analytical gas flow is balanced by the force on the ions due to the electrostatic analytical field. The selected ions are thereby able to follow a stable path to the exit end of the cross-flow mobility analyzer. However, the force on ions of other than the selected mobility is unbalanced and these ions are deflected and lost.

Abstract: An ion optics assembly is formed by four quarter-circular profile elements, all of which are attach to the same reference plate. Consequently, all four elements remain aligned to the same reference plate. The four elements form a quarter-circular channel with quarter-circular quad electrodes. The quad electrodes receive electrical potential to form the field required to focus and maintain the ions at the center of the channel. Quarter-circular insulators are provided on all sides of the channel so as to seal the channel over its length from the interior of the mass spectrometer. A heater is provided at the entrance to the ion transfer optics, to prevent accumulation of ions on the poles. A thermal break is provided in the quad, so as to enable maintaining the front of the quad heated and the rest of the quad cooler.

Abstract: An atmospheric pressure ion source, employing the principle of electrospray ionization, chemical ionization, or photo-ionization, comprises a spray probe for spraying a liquid into an ionization chamber and has an exhaust port through which residual spray mist and waste gas, such as evaporated solvent, are extracted. The ion source further comprises an exhaust system comprising a conduit which is connected to the exhaust port. The conduit has a transition from a first cross-section to a second cross section at a point downstream of the exhaust port wherein the second cross section is reduced in relation to the first cross section. Gas is injected via a gas injector into the conduit in a region of the transition to create a low pressure region that removes unwanted material from the chamber.

Abstract: In one embodiment, a mass spectrometer includes an RF drive circuit for generating RF signals, a quadrupole mass filter, and a fixed connection assembly for delivering RF signals from the RF drive circuit to the quadrupole mass filter, the fixed connection assembly representing the entire delivery path of RF signals from the RF drive circuit to the quadrupole mass filter. By avoiding flexible components such as a freestanding wires or flexible circuit boards, the need for retuning when parts are removed or disturbed for testing or servicing is reduced, and a modular instrument in which components and connections are standardized and therefore interchangeable is realized.

Abstract: Methods and systems to compensate for distortions created by dynamic voltage applied to an electron multiplier used in mass spectrometry. An electron multiplier has a cathode end accepting ion flow, an opposite emitter end and an interior surface. The electron multiplier produces an electron output from ions colliding with the interior surface. A variable power supply has a voltage output coupled to the cathode end and the emitter end of the electron multiplier. The voltage output changes dynamically to adjust the electron output from the electron multiplier. An anode is located in proximity to the electron multiplier. An electrometer is coupled to the anode in proximity to the electron multiplier to measure the current generated by the electron output. A low pass filter circuit is coupled to the emitter end to the ground of the electrometer to attenuate emitter voltage changes. A bias circuit is coupled to the emitter end to stabilize emitter to anode voltage difference.

Abstract: An assembly for use in an electrospray ion source includes a capillary for guiding a flow of liquid generally containing analyte(s) of interest, which is to be electrosprayed into an ionization chamber, a first tube at least partially encasing the capillary such that a first conduit for guiding a first heatable gas is created proximate the capillary and a hollow member that has an internal evacuated space and is located at the outer circumference of the capillary such that heat transfer from the first heatable gas flowing proximate the capillary to the liquid in the capillary is impeded. The assembly provides a simple and lean/compact way of preventing excessive heat transfer to the liquid in the capillary of an electrospray ion source.

Abstract: A mass spectrometer has a manifold and at least one ion optical assembly that is composed of a support and electrodes attached to the support. The support is aligned to at least one reference surface machined integrally with the manifold such that the number of interfaces between the reference surface of the manifold and the electrodes is minimized. With such a design the positional and/or alignment precision of ion optical assemblies in a mass spectrometer can be improved.

Abstract: In one embodiment, a mass spectrometer includes an RF drive circuit for generating RF signals, a quadrupole mass filter, and a fixed connection assembly for delivering RF signals from the RF drive circuit to the quadrupole mass filter, the fixed connection assembly representing the entire delivery path of RF signals from the RF drive circuit to the quadrupole mass filter. By avoiding flexible components such as a freestanding wires or flexible circuit boards, the need for retuning when parts are removed or disturbed for testing or servicing is reduced, and a modular instrument in which components and connections are standardized and therefore interchangeable is realized.