185 results about "Photo ionization" patented technology

An improved ion source and portable analyzer for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions generated by direct or alternating currents, separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques or probes containing samples are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at sub-atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a barrier, comprised of alternating laminates of metal and insulator, populated with a plurality of openings, wherein DC potentials are applied to each metal laminate necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to sub-atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermal-pneumatic ionization sources.

An RF-driven plasma source, including a pair of spaced-apart plasma electrodes, wherein the electrodes act as plates of a capacitor, the gas electrically discharges and creates a plasma of both positive and negative ions, in a clean process that enables efficient sample analysis, with preferred isolated sample photo-ionization, reduced-power operation and also including signal detection with modulated drive electronics.

An apparatus and method for regenerating ion samples for a mass spectrometer are provided. Source samples are loaded on a support which is heated by a laser beam, desorbing the sample without ionization. The desorbed sample is carried by a carrier gas flow through a transfer tube, at the output of which it is ionized by corona discharge or photo-ionization. The obtained ionized sample may be analyzed in a mass spectrometer or used to serve any other appropriate purpose.

The invention discloses a monitoring system of multi-component gas pollutants in air of a chemical industrial park. The monitoring system comprises a PID sensor, an electrochemical sensor, a catalytic combustion sensor, a geographic information determination apparatus a signal conversion apparatus, a memory, a controller, an acousto-optic alarm apparatus, wherein the PID sensor, the electrochemical sensor, and the catalytic combustion sensor commonly form a part for frontal acquisition and detection of the pollutants of the monitoring system, and the part of the monitoring system is used for pollutant kind determination and parameter coupling analysis. The PID sensor comprises a gas acquisition device, a filtering device, and a photo-ionization sensor detection device; the electrochemical sensor comprises a gas acquisition device, a dedusting device, and an electrochemical sensor detector; and the catalytic combustion sensor detector comprises a gas acquisition device, a catalytic combustion sensor detector, and an outrange and reversed polarity protection device. The monitoring system also comprises the controller for statistics and analysis of detection results, and the acousto-optic alarm apparatus for alarm when the gas concentration in the pollutants exceeds a standard.

A photo ionization detector (PID) is provided for selectively determining various compounds or gases present in a breath sample. The PID, comprises a substrate comprising a gas ionization chamber, at least one pair of ion sensing electrodes, and at least one amplifying circuit; and an ultraviolet (UV) ionization source to transmit a UV light beam into the gas ionization chamber. A system comprises the PID is also provided. A method of detecting a response pattern for various compounds or gases in breath using PID is also provided.

The invention relates to a method for identifying and detecting halogenated hydrocarbons, which is characterized by using vacuum ultraviolet as the ionization source of ion mobility spectrometry, adopting the mode of positive-negative ion switching, adopting the principle of photo ionization in the positive ion mode and adopting the principle of photo-electric reflection in the negative ion mode. Being used for detecting halogenated hydrocarbons, the method can widen the type of the compounds measured by the ion mobility spectrometry, greatly improve the capabilities of the ion mobility spectrometry in rapidly identifying and analyzing the samples and simultaneously improve the sensitivity of the ion mobility spectrometry to the compounds with ionization energy lower than that of the vacuum ultraviolet in the negative ion mode.

The invention relates to an ultrasonic atomization sample introduction volatile solvent assisting ionization low-pressure photo ionization mass spectrum device. The device comprises a mass spectrum mechanism. The mass spectrum mechanism comprises a mass spectrum room and a photo ionization room, wherein the mass spectrum room and the photo ionization room are adjacent to each other and are connected together. A rear sampling cone is arranged on one side wall of the mass spectrum room, a mass spectrum room vacuum pump connector is arranged on the other side wall of the mass spectrum room, an ion conveying system and a mass analyzer are arranged in the mass spectrum room, the rear sampling cone stretches into the photo ionization room, a front sampling cone is arranged on one side of the photo ionization room, a photo ionization room vacuum connector is arranged on the other side of the photo ionization room, and a vacuum ultraviolet light source is arranged on the top of the photo ionization room. The device further comprises an ultrasonic atomization mechanism, a heating and gasification mechanism and a volatile solvent introducing mechanism. Objects, not prone to volatilization, to be measured are directly sampled through ultrasonic atomization and heating and gasifying of desolventizing agents without preprocessing, and therefore flexible and fast mass spectrum analysis is achieved, and the device has wide application prospects in aspects like food, pesticides and environment fast mass spectrum analysis.

The present disclosure provides a novel system and method for evaporating and ionizing compounds comprising an LIAD source and an ionization source that operates at atmospheric pressure. This system is readily adaptable for use with most commercially available mass spectrometers. Ionization sources include Atmospheric Pressure Chemical Ionization sources (APCI) and Atmospheric Pressure Photo Ionization (APPI) sources. The ionization sources are positioned such that the analyte desorbing from the surface of the LIAD is fed into the ion stream produced by the ionization source and ionized analyte and ionized fragments of the analyte are fed into the sample inlet of a mass spectrometer. These systems allow for the mass spectrometric analysis of non-polar compounds that lack readily ionizable functional groups, such as saturated and unsaturated hydrocarbons and compounds with medium to low polarity, as well as hydrocarbon mixtures, such as petroleum.

Provided is a discharge ionization current detector. To reduce the cost of a high-voltage power supply unit by reducing the discharge starting voltage for a low-frequency dielectric barrier discharge. Light from light source unit (20) located externally to cylindrical tube (2) through which a plasma gas (He) flows is irradiated through the wall surface of the cylindrical tube (2) onto a plasma generation region (the region between plasma generation electrodes (6 and 7) located in gas flow path (4). The light energy excites the He molecules or the minute quantities of impurity gas molecules present in the He gas, causing photo-ionization. This causes a discharge to start, and a plasma to be formed, when a low-frequency voltage of a voltage that is less than the usual discharge starting voltage is applied across electrode (5) and electrodes (6, 7). Once the discharge starts, the discharge is sustained when the usual discharge sustaining voltage is applied across electrode (5) and electrodes (6, 7). This means that the light source unit (20) has to be on only for a short duration when discharging is started.

The invention relates to a quick on-line atmospheric photo ionization mass spectrum device for an effective constituent in a complex substrate. The device comprises a pre-processing device, an atmospheric photo ionization source and a mass spectrometer, wherein the pre-processing device comprises an ultrasonic atomization mechanism, a volatile solvent introducing mechanism and a heating transfer mechanism. The device can be used for realizing the sensitive, quick and reliable qualitative and quantitative analysis after a to-be-detected sample containing complex substrate (such as, soil remained on explosion site, inferior milk power, food containing illegal additives, rootstocks of medicinal plants and the like) is directly put into the ultrasonic atomization mechanism and is subjected to ultrasonic atomization extraction, and then is delivered to and ionized at the front end of the atmospheric photo ionization source after being subjected to ultrasonic atomization and heating vaporization treatment and being converged with the volatile solvent. The device has wide application prospect at the aspects of discovery and identification of natural products, environment monitoring, criminal investigation, food safety, drug monitoring, etc.

The invention provides a device for qualitatively, quantitatively and quickly detecting pesticide residue on site, which comprises a cavity with an air inlet, an air outlet and an air pump. The device is characterized in that: a dust filter communicated with the air inlet is arranged in the cavity, the dust filter is communicated with a suction type ion migration spectrum measurer in which a multi-pole plate is arranged, and the dust filter is also communicated with a photo-ionization detector in which an ultraviolet lamp, a polarization plate and a collector are arranged; the photo-ionization detector is communicated with a metal oxide semiconductor gas sensor; and the multi-pole plate of the suction type ion migration spectrum measurer, the collector of the photo-ionization detector, the signal pole of the metal oxide semiconductor gas sensor and the air pump are electrically connected with the central control processor. Pesticide residue sample gases on articles such as vegetables,melons and fruits and the like are sucked in a mode of 'smelling and sniffing'; pretreatment and sample preparation are not needed; the sucked gases of the detected article can be conveniently, quickly and accurately detected in real time to acquire components and concentration value of the detected article; quick, reliable and effective guarantee is provided for listed food safety; and in addition, trace gases of toxic and harmful substances can also be effectively and quickly detected.

The invention relates to a laser heating reactor and a photo ionization mass spectrum device used for detecting products in situ. The laser heating reactor is composed of a main cavity, a laser device, a thermodetector, a sample feeding mechanism and a mass spectrum instrument. The technologies such as laser heating, in-situ ultrasound molecular beam sampling and vacuum ultraviolet photo ionization mass spectrum diagnosis are combined, and a novel thermal chemical reaction experimental study technology suitable for the pressure scope from vacuum and barometric pressure to high pressure is provided. Lasers with adjustable power are used for evenly and rapidly heating a reaction substrate, the sample reaction time is shortened, and the secondary reaction is omitted; molecules can be cooled with the ultrasound molecular beam sampling technology, so that unstable intermediate bodies survive; the vacuum ultraviolet soft ionization technology is adopted in vacuum ultraviolet photo ionization mass spectra, fragments are prevented from being produced, and the reaction products can be detected in real time.

The invention discloses a photo ionization detector, comprising a vacuum ultraviolet lamp and an ionization chamber, wherein the ionization chamber comprises two electrodes with minor arc radial cross sections, wherein the electrodes are arranged symmetrically, and comprise a polarized electrode and a collecting electrode. The two electrodes insert into the interior of polytetrafluoroethylene tank in the ionization chamber, such that base current and noise of the electrodes caused by irradiation of the vacuum ultraviolet lamp are avoided. The detector contains an automatically cleaning system to prevent decreasing of sensitivity of the detector caused by pollution of light window and electrodes when the detector is in a continuous operation for a long time. The photo ionization detector suits as a detector of a portable gas chromatograph and a rapid gas chromatograph.

The present invention provides a new method for rapidly and sensitively detecting the total sulfide amount in natural gas. According to the present invention, negative ion mode dopant assisted photo ionization ion mobility spectrometry is adopted as the base detection technology, purified air, oxygen or mixed gas of high-purity nitrogen and oxygen is adopted as carrier gas and drift gas, regent ions having oxidability are formed in the dopant assisted photo ionization source, and sulfides in natural gas are oxidized into the high-valence sulfides having the strong electronegativity so as to achieve the determination on the total sulfur content of the sulfides in the natural gas.

The invention discloses an aerosol mass spectrometer for measuring chemical components of nanoparticles. The aerosol mass spectrometer comprises a nano-scan electromobility particle size spectrometer,a first differential chamber, a second differential chamber, a photo ionization chamber and a reflective type time-of-flight mass spectrum apparatus, wherein the aerosol outlet of the nano-scan electromobility particle size spectrometer is connected with the inlet of the first differential chamber; the outlet of the first differential chamber is connected with the inlet of the second differentialchamber; the outlet of the second differential chamber is connected with the inlet of the photo ionization chamber; and the outlet of the photo ionization chamber is connected with the reflective type time-of-flight mass spectrum apparatus. By virtue of the nano-scan electromobility particle size spectrometer, charge, particle size selection and particle spectrum analysis of the nanoparticles arerealized by the aerosol mass spectrometer, so as to perform real-time and online measurement and acquisition of the chemical component information of the nanoparticles with particle sizes of smallerthan 60nm; and the detection process is simple, and quick and high-efficiency transmission of the nanoparticles are realized.

Embodiments of the present invention relate to detector structures for us in a micro gas analyzer, preferably in a differential setup. The detector structures may comprise one or more detector types, such as photo-ionization (PID), electron capture (ECD), ion mobility (IMS), differential mobility (DMS), ion-trap mass spectrometer (ITMS), in which all are provided with ions and electrons from one vacuum ultra violet (VUV) source. This source may also provide ions for ion-based gas pumps.

The invention discloses a green tea aroma dynamic fingerprint analysis and aroma type discrimination method based on ion mobility spectrometry, and belongs to the technical field of food quality detection. The method comprises the following steps: (1) setting acetone-assisted positive ion mode photoionization ion mobility spectrometry detection conditions; (2) weighing a tea sample, adopting headspace sample injection, and collecting a dynamic fingerprint spectrum which is continuously purged for 3-8 minutes; (3) performing dimension reduction processing on the multi-dimensional original dataof the dynamic fingerprint spectrum obtained in the step (2) to obtain a preprocessed data matrix; and (4) distinguishing and distinguishing different fragrances by utilizing the preprocessed data matrix obtained in the step (3). Green tea sample pretreatment is not needed, so that the detection and analysis time of the tea sample is saved; through ion mobility spectrometry and continuous purgingsample injection, all spectrogram information in a certain period of time can be obtained at the same time, and dynamic fingerprint information is more comprehensive and accurate; and five different fragrances of faint scent, sweet fragrance, tender fragrance, tender chestnut fragrance and cooked chestnut fragrance of the green tea are distinguished and judged.