136 results about "Electron ionization" patented technology

A battery powered portable human body carrying electronic human breath filtration device is an electronic nose mask and is the most ideal alternative to conventional filter paper type nose mask. It utilizes electronic ionization technique and electrostatic field to remove air borne particles, dust, pollens, contaminants, bacteria, viruses, toxic chemical, fume and tobacco smoke from human inhalation and exhalation breath. It interacts with human breathing action as the air flow driving system to move the inhalation and exhalation breaths through the electronic filter elements, in addition to a front louver cover and a rear louver cover's protection as pre-filters. The system requires very low running current and uses small batteries usually found in household electronics. This filtration system is light weight with negligible air flow resistance and is integrated into the nose mask which is connected to a pocket size control system via a connection cable.

The invention provides a mass spectrometric method for analyzing a sample in a solution, including the steps of directing a flow of a solution containing sample compounds to be analyzed towards a supersonic nozzle having an input end and an output end; vaporizing the solution and sample prior to its expansion from the output end of said supersonic nozzle; allowing expansion of the vaporized sample and solution from said supersonic nozzle into a vacuum system, forming a supersonic molecular beam with vibrationally cold sample molecules; ionizing the vaporized sample compounds with electrons while contained as vibrationally cold molecules in said supersonic molecular beam; mass analyzing the ions formed from said sample compounds; detecting said ions formed from said sample compounds after mass analysis, and processing the data obtained from the resulting mass spectral information, for identifying and/or quantifying the chemical content of said sample. The invention also provides apparatus for analyzing a sample in a solution.

Electrospray ionization sources interfaced to mass spectrometers have become widely used tools in analytical applications. Processes occurring in Electrospray (ES) ionization generally include the addition or removal of a charged species such as H+ or other cation to effect ionization of a sample species. Electrospray includes ionization processes that occur in the liquid and gas phase and in both phases ionization processes require a source or sink for such charged species. Electrolyte species, that aid in oxidation or reduction reactions occurring in Electrospray ionization, are added to sample solutions in many analytical applications to increase the ion signal amplitude generated in Electrospray and detected by a mass spectrometer (MS) Electrolyte species that may be required to enhance an upstream sample preparation or separation process may be less compatible with the downstream ES processes and cause reduction in MS signal New Electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes The new electrolyte species increase ES MS signal when added directly to a sample solution or when added to a second solution flow in an Electrospray membrane probe. It has also been found that running the ES membrane probe with specific Electrolytes in the second solution of the ES membrane probe have been found to enhance ESMS signal compared to using the same electrolytes directly in the sample solution being Electrosprayed The new electrolytes can be added to a reagent ion source configured in a combination Atmospheric pressure ion source to improve ionization efficiency.

An ion source for use in a mass spectrometer includes an electron emitter assembly configured to emit electron beams, wherein the electron emitter assembly comprises carbon nanotube bundles fixed to a substrate for emitting the electron beams, a first control grid configured to control emission of the electron beams, and a second control grid configured to control energies of the electron beams; an ionization chamber having an electron-beam inlet to allow the electron beams to enter the ionization chamber, a sample inlet for sample introduction, and an ion-beam outlet to provide an exit for ionized sample molecules; an electron lens disposed between the electron emitter assembly and the ionization chamber to focus the electron beams; and at least one electrode disposed proximate the ion-beam outlet to focus the ionized sample molecules exiting the ionization chamber.

An ion source able to ionize both liquid and gaseous vapors from interfaced liquid separation techniques and a solids/liquid atmospheric pressure (AP) probe. The liquid effluents are ionized by electrospray ionization, photoionization or atmospheric pressure chemical ionization and the vapors released from a probe device placed in a heated gas stream in the AP source are ionized by a corona or Townsend electrical discharge or photoionization. The source has the ability to ionize compounds from both liquid and solid sources, which facilitates ionization of volatile and semivolatile compounds by applying heat from a gas stream as well as highly non-volatile compounds infused by electrospray or separated by liquid chromatography or capillary electrophoresis.

The invention discloses an electrospray ion source, which comprises a hollow capillary tube, a vacuum chamber, electrodes and a direct-current power supply. One end of the hollow capillary tube is used as a sampling end, the other end of the hollow capillary tube is used as an electrospray nozzle, the nozzle and the sampling end are arranged in different pressure environments, the nozzle extends into the vacuum chamber, the pressure for the nozzle is lower than the pressure for the sampling end, the electrodes are arranged in the vacuum chamber and behind the nozzle and are provided with a channel for electrospray to pass through, and the direct-current power supply is applied between the hollow capillary tube and the electrodes. The electrospray ion source can be used as a simple ionization device to generate stable ion flow, and is particularly suitable for use as an ion source of a portable mass spectrometer, and the true real-time online field detection and analysis and electrospray ionization can be realized.

A system for delivery of low-pressure dopant gas to a high-voltage ion source in the doping of semiconductor substrates, in which undesired ionization of the gas is suppressed prior to entry into the high-voltage ion source, by modulating electron energy upstream of the high-voltage ion source so that electron acceleration effects are reduced to below a level supporting an electronic ionization cascade. The gas delivery system in a specific application includes a gas flow passage, a voltage generator electrically coupled with at least a portion of the gas flow passage to impose an electric field thereon, and an obstructive structure that is deployed to modulate acceleration length of electrons of the low-pressure gas in relation to ionization potential of the gas, to suppress ionization in the gas flow passage.

Electrospray ionization sources interfaced to mass spectrometers have become widely used tools in analytical applications. Processes occurring in Electrospray (ES) ionization generally include the addition or removal of a charged species such as H+ or other cation to effect ionization of a sample species. Electrospray includes ionization processes that occur in the liquid and gas phase and in both phases ionization processes require a source or sink for such charged species. Electrolyte species, that aid in oxidation or reduction reactions occurring in Electrospray ionization, are added to sample solutions in many analytical applications to increase the ion signal amplitude generated in Electrospray and detected by a mass spectrometer (MS) Electrolyte species that may be required to enhance an upstream sample preparation or separation process may be less compatible with the downstream ES processes and cause reduction in MS signal. New Electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes. The new electrolyte species increase ES MS signal when added directly to a sample solution or when added to a second solution flow in an Electrospray membrane probe. It has also been found that running the ES membrane probe with specific Electrolytes in the second solution of the ES membrane probe have been found to enhance ESMS signal compared to using the same electrolytes directly in the sample solution being Electrosprayed. The new electrolytes can be added to a reagent ion source configured in a combination Atmospheric pressure ion source to improve ionization efficiency.

An image forming apparatus in which a first substrate provided with an electron-emitting device and an image displaying member which electrons emitted from the electron-emitting device irradiate are arranged to be opposed is provided with a deflecting means deflecting the electrons emitted from the electron-emitting device and a trapping unit trapping an inert gas ionized by the electrons. Thereby, the damages of the electron-emitting device by the inert gas are prevented, and the life of an image display apparatus is aimed to be elongated.

A simple and rugged sheathless interface for capillary electrophoresis/electrospray ionization-mass spectrometry (CE/ESI-MS) was designed using common laboratory tools and chemicals. The interface uses a small platinum (Pt) wire which is inserted into the CE capillary through a small hole near the terminus. The position of the wire inside the CE capillary and within the buffer solution is analogous to standard CE separation operations where the terminus of the CE capillary is placed inside a buffer reservoir along with a grounded platinum electrode. By combining the use of the in-capillary electrode interface with sharpening of the fused silica tip of the CE capillary outlet, a stable electrospray current was maintained for an extended period of time. The design was successfully applied to CE/ESI-MS separations and analysis of mixtures of peptides and proteins. A detection limit of approximately 4 femtomole (S/N=3) was achieved for detection of myoglobin utilizing a 75 mum-i.d. aminopropylsilane treated CE column and using a wide scan range of 550-1350 Da. The advantages of this new design include: (1) a stable CE and ESI current, (2) durability, (3) a reduced risk of sparking between the capillary tip and the inlet of the mass spectrometer, (4) lack of any dead volume, and (5) facile fabrication with common tools and chemicals.

There is provided a mass spectrometric based method for sample identification, including the steps of introducing sample compounds into a vacuum chamber of a mass spectrometer in a seeded supersonic molecular beam, ionizing with electrons the sample compounds, being vibrationally cold molecules, in the supersonic molecular beam during their flight through an electron ionization ion source, mass analyzing the ionized sample compounds with a mass analyzer of a mass spectrometer to obtain a mass spectrum of at least one compound in the sample, identifying the molecular ion group of isotopomers in the mass spectrum, generating various molecular elemental formulas from the identified molecular ion and a pre-allocated list of elements, reducing the number of the molecular elemental formulas by the incorporation of chemical valence considerations and constraints, calculating isotope abundances for the generated elemental formulas, comparing the calculated isotope abundances with the experimentally obtained mass spectral isotope abundance, and listing the generated elemental formulas according to their degree of matching to the experimentally obtained mass spectral isotope abundance.

Methods and apparatus for obtaining a mass spectrum of a sample and determining a concentration of a component of the sample by utilizing a model of chemical and electron ionization and the obtained mass spectrum.

Selective ionization at atmospheric or near atmospheric pressure of a sample diluted in air is provided in multiple steps. Initially, components of air and/or other gas are ionized to generate reactive ions. The reactive ions are then filtered using a high frequency filter to yield selected reactive ions. Thereafter, the selected reactive ions are reacted with sample molecules of a sample being analyzed in a charge transfer process. Depending on the properties of the sample molecules, the filter may select some reactive ions to enter the sample zone and block others entirely thus controlling ion chemistry and charge transfer yields in the sample zone. The described system is directed to controlling ions at the ion source level, using a high frequency filter technique, in connection with subsequent analysis. The method generates the ions of choice for subsequent analysis in such platforms as ion mobility and differential mobility spectrometers.

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.

The invention provides a cathode system for an Electron Ionization (EI) source comprising a filament and current supply posts, the current supply posts dividing the filament into segments and each current supply post supplying or returning the current for at least two segments of the filament. Each filament segment is connected, for instance by spot welding, to the supply posts delivering the heating current. The filament segments may be arranged in a row, or substantially parallel to each other. Filament segments arranged in a row may form a closed loop, for instance, a ring. Other embodiments encompass the filament shape of a helical coil.

Aspects of the present innovations relate to improved systems that may perform capillary electrophoresis (CE) and CE in conjunction with electrospray ionization (ESI) as an input to a mass spectrometry system (MS). Embodiments may use a current sense circuit at a high voltage output from an MS-ESI power supply in conjunction with additional elements to identify fault conditions associated with leakage current, to confirm the continuity of CE connections, and to provide improved system protection.

The invention discloses a controllable high-voltage direct current power supply for an ESI source. The controllable high-voltage direct current power supply comprises an oscillating module, a switching module, a boosting module, a voltage-multiplying rectifying module, a filtering module and an output module, wherein the oscillating module is used for conducting self-oscillation and generating switching signals, the switching module is used for conducting alternate connection under the control of switching signals to output initial alternating voltage, the boosting module is used for boosting the initial alternating voltage to obtain second alternating voltage, the voltage-multiplying rectifying module is used for boosting the second alternating voltage according to a preset multiple and rectifying the boosted voltage to output direct voltage, the filtering module is used for filtering the direct voltage, and the output module is used for outputting the filtered direct voltage. The invention also discloses the ESI source. According to the controllable high-voltage direct current power supply and the ESI source, the high voltage and a strong electric field are provided for the ESI source, so that the ionizing efficiency of samples and the transmission efficiency of produced ions can be greatly improved.