187 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 atmospheric or intermediate pressure, having a remote source of reagent ions 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 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 improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is 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 R2CIS into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources; and improving the sensitivity of chemical detectors or probes.

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.

A method and apparatus are provided for identifying analytes at low concentrations in a liquid sample. The liquid sample is introduced through a continuous flow membrane inlet system. The analytes that permeate the membrane are analyzed by photoionization-time-of-flight mass spectrometry. The analytes remaining in the liquid sample that do not permeate the membrane are conducted to a capillary tube inlet that introduces the liquid sample and other analytes as droplets into the photoionization zone. Any analytes remaining absorbed or adsorbed on the membrane are driven through the membrane by application of heat. Analytes may be analyzed by either resonance enhanced multiphoton ionization (REMPI) or single photon ionization (SPI), both of which are provided in the apparatus and can be selected as alternative sources.

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.

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.

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.

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.

The invention provides improved apparatus for, and methods of, ionizing analyte molecules in a flow of gas, typically at or around atmospheric pressure. The invention may be used to facilitate mass spectrometric analysis of analytes comprised in the effluent form a gas chromatograph. Ionization may be effected by atmospheric pressure chemical ionization or by atmospheric pressure photo ionization.

Methods and systems are provided for the soft desorption of analyte from a sample, in which an optical beam absorbed within an irradiate zone of the sample causes vibrational excitations of a component within the sample. The optical beam, providing sufficient energy to superheat the component, is provided for a time interval that is less than the time duration required for the loss of energy out of the irradiated zone due to thermal diffusion and acoustic expansion. The superheated component thus drives ablation within the irradiated zone, resulting in the soft desorption of analyte without ionization and fragmentation. The ejected ablation plume may be directed towards the inlet of a mass analysis device for detection of the desorbed analyte, which is preferably ionized by a linear resonant photo-ionization step.

An ion mobility spectrometer (IMS) for the detection of trace gaseous molecular compounds dissolved or suspended in a carrier gas, particularly in ambient air, without preconcentration or the trapping of analyte particles. The IMS of the invention comprises an ionization volume of greater than 5 cm3 and preferably greater than 100 cm3. The larger size ionizers of this invention enable analysis of trace (<1 ppb) of sample compounds in the gas phase. To facilitate efficient ion motion through the large volume ionization and reaction regions of the IMS, an electric field gradient can be provided in the ionization region or in both the ionization and reaction regions. The systems can be implemented with radioactive ionization sources, corona discharge ion sources or ions can be formed by photoionization. In specific embodiments, particularly when the sample gas is ambient air, the sample gas is heater prior to entry into the instrument, the instrument is run at temperatures above ambient, and the instrument can be heated by contact with heated sample gas exiting the instrument.

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 present invention relates to an internal photoionization ion trap quality analysis device and its method. Said device includes ion source for making ionization treatment of gas-phase sample and ion trap for making separation treatment of ion, in which the ion source is UV light source, and is placed outside of ion trap to make the UV light be irradiated into the ion trap interior; the gas-phase sample to be tested can be introduced into ion trap interior; the UV light can be used for irradiating gas-phase sample to be tested so as to implement ionization of the gas-phase sample to be test.

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.

A vapor trap for detecting VOCs includes a housing, having a first end portion, a second end portion and at least one opening for receiving gas vapor. The housing is at least partially buried in ground with a vapor containment mechanism detachably connected to the first end portion of the housing. The vapor containment mechanism can be removed and replaced with a vapor sampling mechanism. An organic vapor analyzer can be connected in fluid relationship to the vapor sampling mechanism to measure VOCs. Optionally, a vacuum pump can be utilized to draw vapor into the vapor trap and then subsequently into the organic vapor analyzer. There can be a first selector valve located between the vapor sampling mechanism and the vacuum pump and a second selector valve located between the vapor sampling mechanism and the organic vapor analyzer. A preferred organic vapor analyzer is a photo-ionization detector.

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.

The invention relates to a gas detector, in particular to a portable photo-ionization gas detector, which solves the problems of low detection accuracy and flexibility existing in the prior photo-ionization gas detector. The detector comprises an electrodeless ultraviolet lamp and an ionization chamber of which the inside is provided with two offsetting electrode plates and a collecting electrode plate, wherein the ionization chamber is fixedly provided with a gas inlet end cover and provided with a gas outlet, the electrode plates in the ionization chamber are arranged in parallel and front faces of the electrode plates face each other, and are parallel to a light-transporting direction of the electrodeless ultraviolet lamp; the distance between the two offsetting electrode plates is equal to the height of an optical window of the electrodeless ultraviolet lamp, and the collecting electrode plate is arranged between two offsetting electrode plates; the gas inlet end cover is provided with a gas inlet window where a metallic micro dust filter net and a double-layer microporous filter membrane are arranged. The gas detector has the advantages of simple and reasonable structure, small volume, convenient carrying, accurate detection data, high flexibility and wide application range; moreover, gas detector also meets the real-time and continuous detection requirements in the operating field.

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.

Provided is a method for determining the presence or amount of 5-α-dihydro-3-keto steroids (ADKSs) comprising the steps of preparing a sample for chromatographic separation, subjecting the sample to chromatographic separation, subjecting the chromatographically separated sample to atmospheric pressure photoionization (APPI), and detecting the amount of alkylated parent ions using mass spectrometry or methylated daughter ions by mass spectrometry after collisionally induced dissociation of the alkylated parent ions. Tandem mass spectrometry of ADKSs with a 6-member A ring and a 3-keto group using APPI and methanol as the alkoxy donor will produce methylated daughter ions with a mass / charge ratio of 85.0. Quantitation of this alkylated daughter ion provides a method to detect very low levels of ADKSs such as DHT. This method can also be used for the simultaneous detection of ADKSs and non-ADKSs.

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 relates to a seabed shallow-layer gas detection method based on the MIP-CPT technology. According to the invention, a conventional CPTU probe is additionally provided with an MIP module, thereby enabling organic matters in a ground layer to be continuously decomposed along with the probe and to be diffused through a semi-permeable MIP film during exploration operation when CPTU data is obtained. Then, the organic matters are conveyed to a gas chromatograph on a mother ship, and are detected by a photo ionization detector, a flame ionization detector and a dry-type electrolysis electrical conductivity detector in the gas chromatograph. Testing parameters are obtained through analysis, and the phase state and content condition of organic matters in the ground layer are obtained.

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.

An auto-cleaning and auto-zeroing system (1) comprises a first conduit for flow of ambient gas (16) and a 2nd conduit (22) for flow of ambient air (18). A cleaning chamber (12) removes impurities from ambient air (18). The 1st conduit (20) and 2nd conduit (22) are connected to a valve, operated by the continuous motor, which continuously draws ambient gas (16) or cleaned and filtered ambient air (18) through the system. Cleaned and filtered ambient air (18) enters the ionization chamber (10) to carry out a cleaning (flushing) and a cleaning (ionization) cycle. In this manner, contaminants and pollutants left in the ionization chamber (10) from the measurement of ambient gas (16) are flushed out and removed.

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.