471results about How to "Improve ionization efficiency" patented technology

The showerhead for a CVD apparatus can be easily produced and is capable of forming a film efficiently. The showerhead comprises: a shower plate being made of a metal; and a porous plate contacting a rear face of the shower plate. A plurality of gas diffusion holes are formed in a plate section of the shower plate, which faces a workpiece, and penetrate the plate section in the thickness direction, and the porous plate covers all of the gas diffusion holes.

This invention describes an apparatus for the separation and collection of components in a sample of interest comprising: an ionization source; an ion mobility separator and an ion collector positioned to receive ions leaving the ion mobility separator. The ion mobility separator having an inlet to supply at least one separating substance which comprises particles which selectively interact with at least one analyte component of interest to certain degree different from the others. The analyte component of interest may be enantiomers, diastereomers, stereoisomers, isomers, etc. The ion collector can be used to conduct analytical, preparative, and semi-preparative separation. In addition, a combined primary electrospray and secondary electrospray ionization source is disclosed to enhance ionization efficiency of interest.

An Atmospheric Pressure Chemical Ionization (APCI) source interfaced to a mass spectrometer is configured with a corona discharge needle positioned inside the APCI inlet probe assembly. Liquid sample flowing into the APCI inlet probe is nebulized and vaporized prior to passing through the corona discharge region all contained in the APCI inlet probe assembly Ions produced in the corona discharge region are focused toward the APCI probe centerline to maximize ion transmission through the APCI probe exit. External electric fields penetrating into the APCI probe exit end opening providing additional centerline focusing of sample ions exiting the APCI probe. The APCI probe is configured to shield the electric field from the corona discharge region while allowing penetration of an external electric field to focus APCI generated ions into an orifice into vacuum for mass to charge analysis. Ions that exit the APCI probe are directed only by external electric fields and gas flow maximizing ion transmission into a mass to charge analyzer. The new APCI probe can be configured to operate as a stand alone APCI source inlet probe, as a reagent ion gun for ionizing samples introduced on solids or liquid sample probes or through gas inlets in a multiple function ion source or as the APCI portion of a combination Electrospray and APCI multiple function ion source. Sample ions and gas phase reagent ions are generated in the APCI probe from liquid or gas inlet species or mixtures of both.

A system for the analysis of polyionic molecules by mass spectrometry is provided. The polyionic molecule is attached to a charged tag which neutralizes some of the charge on the polyionic analyte. The formed adduct with a reduced net charge is then analyzed by mass spectrometry, and the determined molecular weight of the adduct can be used to calculate the molecular weight of the analyte. Mass spectrometric analyses of polynucleotides and proteins are particularly amenable to this method.

The invention relates to method and apparatus for production of gaseous ions from components of a condensed phase sample and analysis thereof, wherein one or more liquid jet(s) is/are directed to the surface of the sample to be investigated, where the impact of the liquid jet on the sample surface produces droplets carrying sample particles which are turned into gaseous ions via the evaporation of liquid or, if desired, by a subsequent ionization after the evaporation and the obtained sample particles are analyzed by a known method.

An ion migration spectroscope based on film sample feed-in consists of film sample feeding in unit, vacuum ultraviolet ray source, ionizing reaction region, ion gate, ion floating region and receiving electrode.

The invention provides methods, compositions, apparatus, and a computer data retrieval system for conducting proteomics.

The invention relates to mass spectrometry instruments, in particular to a mass spectrum vacuum ultraviolet ionization source based on an optical-window-free gas discharge lamp. The mass spectrum vacuum ultraviolet ionization source based on the optical-window-free gas discharge lamp comprises the optical-window-free gas discharge lamp and an ionization source cavity, wherein the optical-window-free gas discharge lamp is fixed to the outer wall of the ionization source cavity, a discharge lamp light outlet of the optical-window-free gas discharge lamp is communicated with the ionization source cavity, vacuum ultraviolet emitted by the optical-window-free gas discharge lamp is located inside the ionization source cavity, ion repulsion electrodes, ion transport electrodes and ion extraction electrodes are arranged inside the ionization source cavity and are arranged in sequence in the emergent direction of the vacuum ultraviolet, and the ion repulsion electrodes, the ion transport electrodes and the ion extraction electrodes are arranged at intervals in a coaxial and parallel mode. According to the mass spectrum vacuum ultraviolet ionization source based on the optical-window-free gas discharge lamp, due to the fact that the vacuum ultraviolet with different energy grades and excited-state atoms/ions with different energy grades are generated through gas discharge, ionization selection and ionization efficiency of sample molecules are improved, influence of pollution of an optical window on signal strength can be eliminated, and detection sensitivity and measurement accuracy of the mass spectrum are improved.

A method for directly analyzing a lung cancer tissue sample based on the tissue electro-spray ionization mass spectrometry concretely comprises the steps that an electro-spray extraction ionization source in the tissue sample is set up; an extraction agent, namely, methyl alcohol is sucked through a micro-syringe connected with a quartz capillary, the extraction agent is dripped on the surface of the sample through the quartz capillary, and an injection pump controls the micro-syringe; the lung cancer tissue sample is cut into a piece of which the volume is 1 mm3 and placed at the tip of an acupuncture needle, and the needle tip is inserted into the sample and keep unexposed; the distance between the front end of the sample and an inlet of a mass spectrometer is adjusted, and the tail end of the acupuncture needle, the front end of the sample and the inlet of the mass spectrometer are adjusted to be in a horizontal coaxial state; DC voltage is applied on the acupuncture needle, so that extraction, desorption and ionization happen on the sample, and the sample generates spray which enters the mass spectrometer. According to the method, the information of molecules in the sample can be directly and quickly obtained, and the result shows that the method is a mass spectrometry method which has the advantages that the device is simple, manufacturing cost is low, ionization efficiency is high, and damage to the sample is small.

A discharge ionization current detector capable of supplying plasma gas in large quantity to stabilize plasma simultaneously with lowering the sample dilution ratio to improve detection sensitivity is provided. A gas supply pipe 7 for supplying a plasma gas, which also functions as a dilution gas, is connected to a point near the connecting section of a first gas passage 3 having electrodes 4-6 for plasma generation and a second gas passage having electrodes 16 and 17 for ion detection. A first gas discharge pipe 8 is connected to the other end of the first gas passage 3, and a second gas discharge pipe 13 is connected to the other end of the second gas passage 11. Flow controllers 9 and 14 are provided in the gas discharge pipes 8 and 13, respectively. The flow rate of the gas passing through a plasma generation area and that of the gas passing through an ion current detection area can be independently regulated. Therefore, for example, it is possible to increase the former flow rate to stabilize the plasma and simultaneously decrease the latter flow rate to enhance the detection sensitivity for a low-concentration sample.

Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM² emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M³ emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

Arginine-containing cysteine-modifying compounds useful for MALDI-MS analysis of proteins are provided. These compounds termed isotope-coded ionization enhancement reagents (ICIER) can provide ionization enhancement in MALDI-MS, relative quantitation, and additional database searching constraints at the same time without any extra sample manipulation. More specifically, ICIER increase the ionization efficiency of cysteine-containing peptides by attachment of a guanidino functional group. ICIER also increase the overall hydrophilicity of these peptides due to the hydrophilic nature of ICIER and thus increase the percentage of recovery of these peptides during sample handling and processing such as in-gel digestion or liquid chromatography. Finally, a combination of both light and heavy ICIER provides an accurate way to obtain relative quantitation of proteins by MALDI-MS and additional database searching constraints (number of cysteine residues in every single peptide peak) to increase the confidence of protein identification by peptide mass mapping.

The invention relates to a multi-channel electrospray ion source used in the combination of a micro liquid phase separation system and mass spectrum, wherein 2 to 100 single-channel electrospray nozzle needles/nozzles are fixed on the inlet of the vacuum area of a mass spectrometer, and are distributed in a sector, thereby ensuring that the central axial lines of the tail ends of the single-channel electrospray nozzle needles/nozzles are crossed at the position of 0cm to 1cm away from the front end of the inlet of the vacuum area and are at an angle of 0 degree to 90 degrees to the axial line of the vacuum inlet. When high voltage is respectively applied on each electrospray nozzle needle/nozzle, electrospray ionization of multi-flow path liquid phase can be realized, thereby realizing the combination of a liquid phase separation system and mass spectrum. The ion source has the characteristics of simple structure, easy debugging operation, convenient mode switching, excellent stability and low maintenance cost, etc., and can be directly fixed on a mass spectrometer along with better commonality and practicability. In addition, through installing electrospray nozzle needles/nozzles of different modes, the invention can realize the combination of micro liquid phase separation systems of a plurality of modes and mass spectrum.

The invention discloses a novel gallium nitride based semiconductor laser epitaxial structure and a preparation method thereof. According to the invention, p-AlGaN with gradually variable Al components is adopted to act as an optical confinement layer, and through the principle of polarization doping, three-dimensional hole gas is realized. According to the invention, the activation efficiency ofan acceptor Mg impurity can be improved, the device voltage can be reduced, and simultaneously the internal loss of a laser can be reduced effectively.

Ionization efficiency is improved in Penning ionization capable of selective ionization. A metastable excited species of a rare gas is produced by introducing the rare gas into an ionization space and inducing an electrical discharge, a sample gas is introduced into the ionization space and Penning ionization is produced owing to collision between the sample gas and the metastable excited species of the rare gas. Electrons released from atoms or molecules positively ionized by Penning ionization are captured by applying a positive potential to an electron-capture electrode placed in the ionization space, and the atoms or molecules positively ionized are guided to a mass analyzer.