Abstract: Methods and apparatus are described for time dispersive spectroscopy. In particular, a modulated flow of ionized molecules of a sample are introduced into a drift region of an ion spectrometer. The ions are subsequently detected by an ion detector to produce an ion detection signal. The ion detection signal can be modulated to obtain a signal useful in assaying the chemical constituents of the sample.

Abstract: Disclosed is a high field asymmetric waveform ion mobility spectrometer (FAIMS) with optical based detection of selectively transmitted ions. Light from a light source is directed through an optical port in an electrode of the FAIMS. A light detector is provided for receiving light that is one of transmitted and scattered by the selectively transmitted ions within the FAIMS.

Abstract: The invention provides devices, device configurations and methods for improved sensitivity, resolution and efficiency in mass spectrometry, particularly as applied to biological molecules, including biological polymers, such as proteins and nucleic acids. More particularly, the invention provides methods and devices for analyzing and detecting electrically charged particles, especially suitable for gas phase ions generated from high molecular weight compounds. In one aspect, the invention provides devices and methods for determining the velocity, charged state or both of electrically charged particles and packets of electrically charged particles. In another aspect, the invention provides methods and devices for the time-of-flight analysis of electrically charged particles comprising spatially collimated sources. In another aspect, the invention relates to multiple detection using inductive detectors, improved methods of signal averaging and charged particle detection in coincidence.

Abstract: A technique for providing a grid for a gate such as utilized in gating a stream of ions or other particles in a spectrometer instrument. The grid of wires may, for example, be a so-called Bradbury-Nielson Gate that consists of a set of two electrically isolated sets of equally spaced wires that lie substantially in the same plane and alternate in potential. The method utilized to provide is to first fabricate a frame of an insulating substrate having a hole and depositing metal film patterns such that conductive portions are formed on either side of the hole. Conductive portions on either side form a series of terminating pads on the portion of the substrate closest to the hole and a bus bar. Grid wires are then formed by stretching a section of wire with desired constant tension across the hole and bonding the ends of the wire to a respective one of the pads on one side and bus bar on the other side. The method provides a rapid, inexpensive way to fabricate such modulating devices.

Abstract: An ion storage system is described that includes an ion trap that defines a volume for storing a plurality of ions. A radio frequency (RF) generator is electromagnetically coupled to the volume defined by the ion trap. The RF generator generates an RF electrical field that stores the plurality of ions in the ion trap. A switching device terminates the RF electrical field, which ejects the plurality of ions from the ion trap. An ion detector detects at least a portion of the plurality of ions that are ejected from the ion trap.

Abstract: A method and an apparatus is disclosed for selectively transmitting ions with a FAIMS analyzer in which a flow of carrier gas of a mixed composition is provided. Ions that are transmitted at a same combination of applied potentials when a first carrier gas is provided are in certain cases transmitted at different combinations of applied potentials when a second other carrier gas having a different composition is provided.

Abstract: A tandem time-of-flight mass spectrometry including a pulsed ion generator, a timed ion selector in communication with the pulsed ion generator, an ion fragmentor in communication with the ion selector, and an analyzer in communication with the fragmentation chamber. The fragmentation chamber not only produces fragment ions, but also serves as a delayed extraction ion source for the analyzing of the fragment ions by time-of-flight mass spectrometry.

Abstract: By connecting the Bradbury-Nielson gate (BNG) directly to a driver without a transmission line, distortion of the voltage waveform experienced a the BNG are much reduced. Because the magnitude of the modulation defects grows as the applied modulation voltage is increased, Bradbury-Nielson gates with finer wire spacing such as 100 microns, and operating at 10 to 15 V, significantly better signal-to-noise ratios are achieved. HT-TOFMS data were also post processed using an exact knowledge of the modulation defects.

Abstract: A method for processing time-dependent signal data is disclosed. The time-dependent signal data are received in a memory, wherein the time-dependent signal data represent a time-dependent signal, and wherein the time-dependent signal data include representations of time-of-flight values of ions, or values derived from time-of-flight values of ions. The time-dependent signal data are scaled with a time-dependent scaling function.

Abstract: An ion trap mobility spectrometer is provided. The ion trap mobility spectrometer employs algorithms to simultaneously detect and analyze both positive and negative plasmagrams. Selectivity is improved by detecting the presence of peaks in both spectra and setting logic filters which require the presence or absence of certain peaks in both spectra. Selectivity is improved by looking for two peaks in the two spectra.

Abstract: In order to provide an equipment that permits easy elimination of interference ions even in a low resolution mass spectrometer, the isotope mass number information and the isotope presence ratio information for each element are stored, and processing is done as is shown in FIG. 1 using such information and the measurement results, and the amount of target elemental ions is calculated by calculating and eliminating the amount of interference caused by other elemental isotopes to the target element. Because of this, when carrying out element analysis using a mass spectrometer with a relatively low resolution, the user can easily obtain the measurement result of the amount of any target elemental ions.

Abstract: A field asymmetric ion mobility spectrometer apparatus and system including a sample preparation and introduction section, a head for delivery of ions from a sample, an ion filtering section, an output part, and an electronics part wherein the filter section includes surfaces defining a flow path, further including ion filter electrodes facing each other over the flow path that enables the flow of ions derived from the sample between the electrodes and wherein the electronics part applies controlling signals to the electrodes for generating a filter field for filtering the flow of ions in the flow path while being compensated to pass desired ion species out of the filter.

Abstract: Disclosed are an apparatus and a method for separating ions in the gas phase. An apparatus according to the instant invention includes a high field asymmetric waveform ion mobility spectrometer including an inner electrode having an outer surface and a length. The apparatus further includes an outer electrode having an inner surface and a length and surrounding the inner electrode over at least a portion of the length of the inner electrode, the inner electrode and the outer electrode defining an analyzer region therebetween and being disposed in a spaced apart arrangement for allowing ions to propagate therebetween. The outer electrode also includes an outlet from the analyzer region and at least a first ion inlet and a second distinct ion inlet into the analyzer region. The first ion inlet and the second distinct ion inlet are each for communicating with at least one ionization source.

Abstract: A method for trapping of a plurality of charged particles in a charged particle trap. The trap includes first and second electrode mirrors having a common optical axis, the mirrors being arranged in alignment at two extremities thereof. The mirrors are capable, when voltage is applied thereto, of creating respective electric fields defined by key field parameters. The electric fields are configured to reflect charged particles causing their oscillation between the mirrors. The method includes introducing into the trap, along the optical axis, the plurality of charged particles as a beam having pre-determined key beam parameters. The method further includes choosing the key field parameters for at least one of the mirrors such as to induce bunching among charged particles in the beam.

Abstract: A method for carrying out nitrogen analysis by ionization mobility spectroscopy at concentrations of few parts per billion (ppb) in argon is described. The method involves the addition of hydrogen in concentration of at least 5 ppb and lower than 100 parts per million (ppm) to the argon to be analyzed; the hydrogen addition step may be preceded by a purification operation of the argon flow to reduce the total concentration of impurities other than nitrogen to under 1 ppb.

Abstract: The invention relates to an energy-focusing and space-angle focusing reflector for time-of-flight mass spectrometers. The invention consists in producing an adjustable space-angle focusing system by means of an adjustably weaker field with curved equipotential lines at the end of the reflector instead of a fully homogeneous electrical reflection field.

Abstract: An ion mobility spectrometer (IMS) has a non-radioactive electron source and an x-ray anode in an evacuated chamber. The impinging of electrons from the source on the anode results in the generation of x-ray radiation. The x-ray radiation passes through a window that provides a vacuum barrier between the electron source chamber and a reaction chamber of the IMS by an x-ray window. A support grid is attached to the reaction-chamber side of the x-ray window, and mechanically stabilizes the window.

Abstract: A high speed analog to digital converter (“ADC”) that can be used in a detector system. The ADC is coupled to a detector and a processor. The detector generates an analog signal in response to the detection of a trace sample, such as an ionized molecule or a beam of light. The processor determines a baseline value and threshold value. Portions of the analog signal at or below the threshold are assigned the baseline value. The threshold typically corresponds to a value above the noise level in the system. The detector thus removes undesirable noise from the readout value. The process can compensate for factors such as DC drift while providing accurate data regarding detection of the trace sample.

Abstract: A mass spectrometer system comprising a laser and a mass spectrometer. The mass spectrometer has a vacuum interface that provides entrance of a gaseous sample into an extraction region of the mass spectrometer. The laser is positioned to provide laser light incident on a sample non-gaseous substance positioned adjacent the vacuum interface. The laser light provides vaporization of the sample, which provides a high concentration of gaseous molecules from the sample substance at the vacuum interface.

Abstract: A low-power, plasma source-based, portable molecular light emission generator/detector employing an atmospheric pressure pulsed-plasma for molecular fragmentation and excitation is described. The average power required for the operation of the plasma is between 0.02 W and 5 W. The features of the optical emission spectra obtained with the pulsed plasma source are significantly different from those obtained with direct current (dc) discharge higher power; for example, strong CH emission at 431.2 nm which is only weakly observed with dc plasma sources was observed, and the intense CN emission observed at 383-388 nm using dc plasma sources was weak in most cases. Strong CN emission was only observed using the present apparatus when compounds containing nitrogen, such as aniline were employed as samples. The present apparatus detects dimethylsulfoxide at 200 ppb using helium as the plasma gas by observing the emission band of the CH radical.

Abstract: A pancake field asymmetric waveform ion mobility spectrometer (FAIMS) uses radial filtering and detection of selection ion species in a compact pancake package to provide enhanced resolution and fast response time. A sample containing a mixture of compounds is ionized in a chamber and then ion species representing the various compounds in the sample are passed to a FAIMS ion filter. Compensated FAIMS filter fields dictate passage through the filter of ion species of certain mobility behavior and trajectory. The detector detects ions that have passed through the FAIMS filter wherein the filter and detector electrodes are formed radially spaced on facing substrates.

Abstract: An ion mobility spectrometer comprising a drift tube having a central axis, along which a plurality of ring electrodes are arranged is provided. The plurality of ring electrodes provides a linear potential gradient along the central axis of the drift tube. In addition an RF voltage source coupled to the plurality of ring electrodes generates an oscillating RF potential within the internal region of each of the ring electrodes. The oscillating RF potential influences radial motion of the ions within the drift tube so that the ions remain within a radial space defined by the internal regions of the electrodes.

Abstract: The invention relates to a time-of-flight mass spectrometer for injection of the ions orthogonally to the time-resolving axis-of-flight component, with a pulser for acceleration of the ions of the beam in the axis-of-flight direction, preferably with a velocity-focusing reflector for reflecting the ion beam and with a flat detector at the end of the flight section. The invention consists of using, both for acceleration in the pulser and for reflection in the reflectors, a gridless optical system made up of slit diaphragms which can spatially focus the ions onto the detector in the direction vertical to the directions of injection and flight axis, but which does not have any focusing or deflecting effect on the other directions. For some reflector geometries it is essential to use an additional cylindrical lens for focusing, and for other reflector geometries the use of such a lens may be advantageous.

Abstract: The invention relates to methods and instruments for measuring daughter-ion spectra in reflector time-of-flight mass spectrometers with post-acceleration of parent and daughter ions selected by means of a parent-ion selector. The invention consists of using a second selector to mask out all or at least a large fraction of the parent ions as well as those metastable daughter ions, which are produced by the decomposition of parent ions after post-acceleration. These ions not only produce ‘ghost’ peaks but also a high level of background noise as well as a parent ion peak which is excessively saturated and cannot be evaluated. This peak's ion current is capable of damaging the detector.

Abstract: This invention relates to a quadrupol ion trap mass spectrometer with improved sensitivity for massive molecules by using cryogenic particle detectors as molecule detectors. Cryogenic particle detectors have a mass independent detection efficiency and do not show a decrease of detection efficiency for increasing molecule mass as compared to ionizing detectors which are used in common quadrupol ion trap mass spectrometers.

Abstract: An ion trap mobility spectrometer is provided with a reaction chamber and a drift chamber. Ions are produced in the reaction chamber by high voltage electronic pulses. More particularly, the ions are formed periodically and are allowed to thermalize in a field-free environment of the reaction chamber. The ions then react with molecular species in the gas phase in the reaction chamber. After a short period, the ions are pulsed into the drift section and are collected on a collector electrode disposed at the end of the drift chamber remote from the reaction chamber. The reaction period may be varied to sample the ion population at different intervals. This enables the ion-molecule reactions to be monitored as the ion population approaches equilibrium. The monitoring results can be used to determine differences between reacting species because the molecular ion population varies at different time points approaching equilibrium. This in turn provides improved identification of target materials.

Abstract: Method and apparatus for the analysis of compounds using electrospray in high field asymmetric ion mobility spectrometry.

Abstract: A summed TOFMS having a filter for identifying detector outputs that are likely the result of noise rather than ions striking the ion detector. The TOFMS stores a plurality of data values at locations specified by a register that counts clock pulses. The filter receives the ion measurements from the ion detector and generates an output measurement value corresponding to each ion measurement. The filter sets the output measurement value to a predetermined baseline value if the filter determines that the ion measurement is noise, otherwise the filter sets the output measurement value to the ion measurement. An adder, responsive to the clock signal, forms the sum of the data value specified by the register value and the output measurement value and stores the sum in the memory at the location corresponding to the register value.

Abstract: There is disclosed a time-of-flight (TOF) mass spectrometer using microchannel plates (MCPs), that are prevented from saturating even if strong ion pulses hit the microchannel plates. Usually, the saturation would result in a dead time, removing parts of the produced mass spectrum and shortening the lifetimes of the microchannel plates. An intermediate ion detector is mounted at the spatial focusing point of a reflectron TOF-MS spectrometer portion to measure the current values of ion pulses arriving from an external ion source, as well as the elapsed times since start of travel of the ion pulses. Information obtained by the measurement is fed back to the final ion detector. Thus, the gain of the final ion detector is controlled before the ion pulses reach the final ion detector. This prevents saturation of the final ion detector. The invention can also be applied to a TOF mass spectrometer using pulsed ionization and to an electrostatic sector field TOF mass spectrometer.

Abstract: Generally, the present invention provides a device for heating the sample stream inlet of an ion mobility spectrometry (IMS) sensor. The heating device increases the temperature of the sample stream inlet surface to reduce the amount of time between adsorption and desorption taking place on the surface. This greatly improves the ability of the IMS sensor to follow rapidly changing analyte concentration levels. An alternate preferred embodiment of the present invention provides a flow smoothing device for decreasing the turbulence present in the fluid flow entering the IMS sensor's carrier stream inlet. This flow smoothing insert permits increasing the fluid flow rate entering the IMS sensor's carrier stream inlet to levels which maximize the IMS sensor's measurement sensitivity without causing mixing of the sample and carrier fluid stream flows.

Abstract: Mass spectometer system and method of use are disclosed. Briefly described, one embodiment of the mass spectrometry system, among others, includes a radio frequency multipole assembly, an inner structure, and a laser diode array system. The inner structure has an outside, an inside, and an opening. The inner structure substantially surrounds the radio frequency multipole assembly. The laser diode array system is disposed on the outside of the inner structure adjacent the side opening such that laser radiation emitted from the laser diode array system travels through the side opening.

Abstract: This invention is generally in the field of improved ion mobility spectrometry. The improvement lies in the use of periodic focusing electric fields that minimize the spatial spread of the migrating ions by keeping them in a tight radius about the axis of travel. The resulting enhancement in sensitivity is accomplished without a concomitant loss in resolution as would normally be expected when non-linear fields are used.

Abstract: Depending on the RF driving voltage amplitude value and the frequency of each frequency component of wideband auxiliary AC voltages, the wideband auxiliary AC voltage comprising plural different frequency components is optimized so that undesired ions having mass-to-charge ratios within the required range will be resonantly ejected from the ion trap electrodes.

Abstract: An ion mobility spectrometer includes a housing with a flow channel, an air pump to force air through the flow channel, a heater at an inlet end of the flow channel, and an ionization source that ionizes the air after it is heated. The heated, ionized air passes through an electric field produced by a field source and a plurality of sensor elements located within in the wall of the flow channel in the measurement region of the electric field. The sensor elements include a plurality of sensor electrodes in one wall of the flow channel. Ion currents to the sensor electrodes are measured by an integrated high-sensitivity readout circuit array, permitting the sensor electrodes to be quite small. The sensor electrodes may be arranged in one-dimensional or two-dimensional arrays.

Abstract: A system for sampling the ambient air of a selected environment for the presence of unwanted chemical vapors, such as nerve or blister gases includes an external air sampling unit and a detector unit having first and second ion mobility spectrometers which simultaneously detect and monitor for the presence of the chemical agent vapors so as to provide an accurate and quick determination of the unwanted chemical vapor within the selected environment.

Abstract: The present invention provides an apparatus for selectively transmitting ions and trapping the ions within a defined 3-dimensional space at atmospheric pressure. The invention is based on the ion focussing principles of high field asymmetric wave-form ion mobility spectrometry in which an analyzer region is defined by a space between first and second spaced apart electrodes, the analyzer region having a gas inlet and a gas outlet for providing a flow of gas through the analyzer region. Ions which are introduced into the analyzer region are carried by a gas flow towards a gas outlet. At least one of the electrodes has a curved surface terminus located near the gas outlet and the gas flow is adjusted so that ions are trapped in a defined 3-dimensional space located near the tip of the terminus. Trapping of ions in a defined 3-dimensional space allows a more concentrated flow of desired ions.

Abstract: The invention relates to the construction and operation of a slit diaphragm pulser for a time-of-flight mass spectrometer with orthogonal injection of the ions to be examined. The invention includes switching three diaphragm potentials during a transition from a filling phase to an acceleration phase in order to maintain a potential along the axis of the injected ion beam at a constant level, to prevent any penetration by the accelerating fields during the filling phase and to obtain extremely high mass resolution in the acceleration phase through a lens effect.

Abstract: A soft ionization device is disclosed that comprises a series of electrodes having pacing less than the means free path of the molecules to be ionized. In some embodiments, the soft ionization device is used in various applications that require ion or electron sources such as biological or chemical reactors, ion milling, and numerous replacements for conventional hot cathode systems. In another embodiment, a valence spectrometer is disclosed that is configured to variably ionize molecules by their valiancy. In other embodiments, the ionization device is coupled to a spectrometer for the characterization of biological matter. Also disclosed is a preconditioner for preparing biological matter to be ionized.

Abstract: A method and apparatus for screening an object for the presence of an explosive, chemical warfare agent, biological warfare agent, drug, metal, weapon, and/or radioactive material. The apparatus includes a portal through which the object is arranged to pass, the portal including a housing equipped with an ion mobility spectrometer and a surface acoustic wave device for detecting explosives, drugs and chemical warfare agents. In another embodiment the housing is equipped with a biological warfare agent detector, chemical warfare agent detector, metal detector, x-ray system, and/or radiation detector.

Abstract: An ion mobility spectrometer includes a housing with a flow channel, an air pump to force air through the flow channel, a heater at an inlet end of the flow channel, and an ionization source that ionizes the air after it is heated. The heated, ionized air passes through an electric field produced by a field source and a plurality of sensor elements located within in the wall of the flow channel in the measurement region of the electric field. The sensor elements include a plurality of sensor electrodes in one wall of the flow channel. Ion currents to the sensor electrodes are measured by an integrated high-sensitivity readout circuit array, permitting the sensor electrodes to be quite small. The sensor electrodes may be arranged in one-dimensional or two-dimensional arrays.

Abstract: Method and apparatus for the analysis of compounds using electrospray in high field asymmetric ion mobility spectrometry.

Abstract: Bradbury-Nielson gates for the modulation of beams of charged particles, particularly ion beams in mass spectrometry, have been produced with an adjustable wire spacing down to 0.075 mm or a smaller spacing. The gates are robust, they can be fabricated in less than 3 hours, and the method of production is reproducible. In time-off-light mass spectrometers, fine wire spacing leads to improvements in mass resolution and modulation rates. Gates that were produced using this new method have been installed in a Hadamard transform time-of-flight mass spectrometer in order to demonstrate their utility.

Abstract: A method and a system for monitoring combustion condition are provided for monitoring the state of combustion in a garbage incinerator, an internal combustion engine, or the like. Combustion off-gas produced by combustion is collected and ionized to produce ions which are fed to a mass spectrometer for detecting a signal strength associated with an ion for each mass-to-charge ratio. The degree of unsaturation is calculated for an ion detected by the mass spectrometer from the mass-to-charge ratio of the ion. Then, signal strength values associated with ions having the same degree of unsaturation are accumulated for each degree of unsaturation. The monitoring system can keep track of components in combustion off-gas classified into respective compound groups in real time to monitor an exact combustion condition.

Abstract: An ion mobility spectrometer comprising a drift tube having a central axis, along which a plurality of ring electrodes are arranged is provided. The plurality of ring electrodes provides a linear potential gradient along the central axis of the drift tube. In addition an RF voltage source coupled to the plurality of ring electrodes generates an oscillating RF potential within the internal region of each of the ring electrodes. The oscillating RF potential influences radial motion of the ions within the drift tube so that the ions remain within a radial space defined by the internal regions of the electrodes.

Abstract: A micromechanical field asymmetric ion mobility filter for a detection system includes a pair of spaced substrates defining between them a flow path between a sample inlet and an outlet; an ion filter disposed in the path and including a pair of spaced filter electrodes, one electrode associated with each substrate; and an electrical controller for applying a bias voltage and an asymmetric periodic voltage across the ion filter electrodes for controlling the paths of ions through the filter.

Abstract: An ion mobility spectrometer is disclosed which includes a sample input port, an ion generator, an ionization chamber receiving and ionizing samples, an ion gate for causing the ionized samples to travel in a direction, and a drift region for receiving the directed ionized samples and for subjecting the ionized samples to an electric potential. The ionized samples then separate according to their electric charge and mass and are detected by a sensor having an output with linear, non-linear, and logarithmic characteristics. The ion mobility spectrometer further includes circuitry coupled to the sensor for linearizing the output such that the non-linear and logarithmic characteristics are linearized while preserving the linear characteristics.

Abstract: An ion mobility spectrometer (IMS) is provided that has a non-radioactive electron source in an evacuated chamber that is separated from the reaction chamber of the IMS by an x-ray window. Electrons from the source impinge upon an x-ray anode, causing the emission of x-ray radiation toward the window. A current controller is provided by which currents in the electron-source chamber are monitored and controlled using a microprocessor circuit. If a maximum permissible residual gas pressure is exceeded, the electron source is automatically shut down and a gettering process is activated.

Abstract: A high voltage ion propulsion field is applied across the length of an ion mobility spectrometer that is divided by a barrier wall into a desolvation region and a drift tube. A plume of ions and solvent is electrosprayed into the desolvation region, and ions are propelled from the desolvation region through the drift tube to an ion target. Drift gas flows through the drift tube in the opposite direction to oppose the ion flow. A portal in the barrier wall permits ions to move from the desolvation region into the drift tube, and restricts flow of drift gas from the drift tube into the desolvation region. The resulting drift gas velocity increase effects desolvation without requiring elevated temperature or decreased pressure. An ion gate is located near the portal and an aperture grid is located near the ion target. The drift gas flow rate is varied to change the ionization spectra to alter selectivity.

Abstract: Methods and apparatus are described for time dispersive spectroscopy. In particular, a modulated flow of ionized molecules of a sample are introduced into a drift region of an ion spectrometer. The ions are subsequently detected by an ion detector to produce an ion detection signal. The ion detection signal can be modulated to obtain a signal useful in assaying the chemical constituents of the sample.

Abstract: A combinatorial chemistry system allows for the dual processing of different molecules coated on a library of beads. The system includes beads coated with different molecules on each bead, a bead holder, screening equipment and characterization equipment. Molecules on the beads are both screened and characterized simultaneously.