66 results about "Photo ionization" patented technology

The invention discloses a composite ion source device for coupling atmospheric pressure interface orbitrap mass spectrometry, which belongs to the field of mass spectrometry detection and comprises a photo ionization / photo-induced association ionization ionization and ion transmission mechanism, a gas sample introduction mechanism, a high-flux radio frequency vacuum ultraviolet light source mechanism and an ion source and mass spectrometry interface mechanism. By adopting the composite ion source device for coupling the atmospheric pressure interface orbitrap mass spectrum, organic components with different polarities, ionization energy and ion affinity in a complex mixture can be efficiently ionized, and through reasonable structural design, the organic components are coupled with the high-resolution orbitrap mass spectrum with the atmospheric pressure interface, so that the high-resolution orbitrap mass spectrum is obtained. The detection range of complex organic components is widened, and the resolution capability and the detection sensitivity of low-abundance or high-molecular-weight organic components are improved.

The invention relates to an atmospheric pressure photo ionization rapid desolventizing device and method, and the device comprises a sampling valve which is installed on a sampling pipe of a high-pressure reactor and can be opened and closed according to a preset frequency; the atomizing unit is mounted on the sampling pipe at the downstream of the sampling valve and is used for atomizing a sample solvent; an inlet of the laval spray pipe is connected with an outlet of the sampling pipe, and an outlet of the laval spray pipe is led to a normal-pressure photo ionization area, so that a solvent is subjected to flash evaporation removal, and a product flows to the photo ionization area to realize ionization; wherein the Laval nozzle is provided with a temperature control system which is used for controlling the temperature of the Laval nozzle. According to the method, the solvent can be quickly removed, the integrity of thermal instability components is ensured, and the analysis accuracy is improved.

The present application relates to a kind of photoionization ion mobility spectrometry of fast switching combination reagent ion, including photoionization ion mobility spectrometry, reagent ion generation device, reagent molecule carrier gas is introduced to reagent molecule into the reaction zone of ion mobility spectrometry, different types of reagent ions can be obtained by switching different gas paths and reagent molecules in positive ion mode, and the reagent ions in conventional gas flow mode are mainly (C3H6O)2H + , after switching combination gas path device, new hydrate cluster reagent ion H3O (H2O) n + Is generated by the regulation of acetone and water reagent molecule, and the reactivity is higher, the sensitivity of target detection is higher, so that by switching different gas paths, the high sensitivity and high selectivity detection of target compound can be realized, such as the detection of exhaled air ammonia and atmospheric ammonia in complex matrix background, and any sample pretreatment process is not needed.

A photoionization detector (PID) is disclosed that includes an ionization chamber configured to allow a flow of a gas sample therethrough, the ionization chamber defining an ionization region and a detection region, a photoionization source configured to generate ionizing radiation for irradiating the flow of the gas sample in the ionization region, an electric-field ionization source configured to apply an ionizing electric field inside the ionization chamber to intersect the flow of the gas sample in the ionization region, the ionizing radiation and the ionizing electric field being configured to ionize the gas sample, and an ion detector configured to detect, in the detection region, an ionization current resulting from the ionized gas sample. The PID may also include an optical window, for example, made of a window material including sapphire, configured to allow at least part of the ionizing radiation to pass therethrough prior to entering the ionization region.

This invention discloses a miniaturized portable mass spectrometer based on a vacuum ultraviolet photoionization source and its analytical method, relating to the field of mass spectrometry analysis technology. The mass spectrometer includes: a sample introduction and pre-screening module, consisting of a sample introduction system and an intelligent sample pre-screening unit. The sample introduction system enables gas-liquid sample switching. The pre-screening unit collects data through physical and chemical characteristic detection subunits, and outputs target compound type and parameter adjustment instructions after processing by a data analysis subunit. This invention, through the intelligent sample pre-screening unit in the sample introduction and pre-screening module, utilizes physical and chemical characteristic detection subunits to quickly acquire physicochemical characteristic data such as the color spectrum, volatile components, and pH value of the sample. The compound type recognition model built into the data analysis subunit can automatically compare with the sample characteristic database, quickly identify the target compound type, and generate ionization source parameter adjustment instructions, greatly simplifying the operation process and reducing detection time.

The present invention relates to a method for highly sensitive in-situ detection of reaction transient intermediates under high pressure, including sampling: obtaining intermediate products and target products in a high-pressure reaction chamber under a pressure difference to obtain a particle beam to be analyzed; photoionization: irradiating the particle beam to be analyzed with extreme ultraviolet light to cause photoionization of the particle beam to be analyzed, obtaining detectable charged ions; mass spectrometry analysis: performing mass spectrometry analysis on the charged ions obtained by photoionization, and obtaining a reaction mechanism according to the mass spectrometry analysis results; the photoionization and the mass spectrometry analysis are both carried out under the condition that the vacuum degree is ≤1×10<supgt;‑8< / supgt; Torr. An apparatus for implementing the method is also disclosed. Compared with traditional methods, the present invention can deeply understand the actual catalytic reaction mechanism and provide a scientific basis for improving the performance of catalysts. The present invention can achieve in-situ characterization of catalytic reactions under normal pressure or even a certain pressure.

The present invention discloses a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, belonging to the field of mass spectrometry detection, and comprising a photoionization / photoinduced association ionization and ion transmission mechanism, a gas sampling mechanism, a high-throughput radio frequency vacuum ultraviolet light source mechanism, and an ion source and mass spectrometer interface mechanism. The present invention adopts the above-mentioned composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, so that organic components of different polarities, ionization energies, and ion affinities in complex mixtures can be efficiently ionized. Through reasonable structural design, the device is coupled with a high-resolution orbital trap mass spectrometer with an atmospheric pressure interface to achieve a broadened detection range of complex organic components and improve the resolution and detection sensitivity of low-abundance or high-molecular-weight organic components.

The application discloses a photoionization and discharge ionization combined ion source. After sample molecules are photoionized, the sample molecules are focused through an ion transmission hexapole, and the peak-to-peak value of a radio frequency voltage applied to the ion transmission hexapole is increased, so that discharge ionization is introduced between the ion transmission hexapole and an open electrode. Sample molecules which are not photoionized can be continuously subjected to discharge ionization, so that the signal strength and sensitivity are improved. Meanwhile, the discharge ionization has high energy, can ionize substances which cannot be ionized by photoionization, and widens the application range of the ion source.

The invention discloses a high-sensitivity aerosol single particle laser ionization device and a mass spectrometer. The high-sensitivity aerosol single particle laser ionization device comprises a pulse laser, an ultraviolet laser reflecting lens, a focusing lens, a re-reflecting lens and a concave reflecting mirror; the pulse laser, the ultraviolet laser reflecting lens, the focusing lens, the re-reflecting lens and the concave reflecting mirror are sequentially distributed along the advancing direction of the optical path, the pulse laser is used to generate pulse laser ionization aerosol single particles, the ultraviolet laser reflecting lens is used to reflect the pulse laser generated by the pulse laser to the focusing lens, the focusing lens is used to focus the pulse laser to the front surface of the aerosol single particle, the re-reflecting lens is used to reflect the re-amplified laser focused on the aerosol single particle and reflect it to the concave reflecting mirror, and the concave reflecting mirror is used to reflect and refocus the amplified laser to the rear surface of the aerosol single particle. The high-sensitivity aerosol single particle laser ionization device can improve the ionization sensitivity.

The invention relates to the technical field of mass spectrum analyzers, in particular to an orthogonal electrochemical mass spectrum device. Comprising a photoionization system, an electron ionization system and an electrochemical reaction tank, the electrochemical reaction tank is sequentially connected with the photoionization system and the electron ionization system through a vacuum sampling pipe, and the photoionization system ionizes volatile organic compound gas generated in the electrochemical reaction tank to obtain a soft ionization spectrogram of the volatile organic compound gas; the electron ionization system is used for ionizing inorganic components generated in the electrochemical reaction tank to obtain an inorganic component mass spectrum. The photoionization source and the electron ionization source are ingeniously and orthogonally combined, soft ionization of volatile organic compounds and effective ionization of high-ionization-energy inorganic compounds in the electrochemical process can be achieved at the same time, and therefore the real-time concentration change trend of the volatile organic compounds and inorganic compounds is obtained.

The application discloses a kind of gas-phase pollutant full-species high-sensitivity online mass spectrometer and detection method, it is related to mass spectrometry technical development technical field.Mass spectrometer includes high-energy photoionization ion source structure, ion transmission structure and mass spectrum detection structure.High-energy photoionization ion source structure includes high-energy photon generation structure, sample introduction tube and ionization chamber, high-energy photon generation structure utilizes neon discharge to generate high-energy photon, high-energy photon is mixed with the gas to be measured that enters through sample introduction tube in ionization chamber, and the gas to be measured is ionized;Ion transmission structure is equipped with radio frequency quadrupole rod, for filtering the large amount of N2 + And O2 + Non-target background ions generated when measuring air;Mass spectrum detection structure is equipped with pulse-compensation double-electrode ion removal device, for further removing non-target background ions, relieving the measurement saturation and loss of ion detector.The application can realize the full coverage high-sensitivity detection of all gas-phase organic and inorganic pollutants in atmosphere.

The invention belongs to the field of mass spectrum ionization, and particularly relates to a photoinduced Penning ionization mass spectrum method. Photoelectrons generated by a photoelectric effect accelerate in an electric field to obtain enough energy, helium He, neon Ne and argon Ar in ground states are excited to metastable states, and the energy of the metastable states of the neutral atoms is higher than 10.6 eV (He excitation energy is 20.62 eV and 19.82 eV); the excitation energy of Ne is 16.72 eV, and the excitation energy of Ne is 16.62 eV; the excitation energy of Ar is 11.72 eV and 11.55 eV), sample molecules with ionization energy higher than photon energy and incapable of being ionized by traditional photoionization can be ionized through Penning ionization, so that the reduction of mass spectrum resolution, sensitivity and quantitative capacity caused by a space charge effect caused by coulomb repulsion among too strong reagent ions in an ion transmission process is avoided, and the detection sensitivity is improved. And damage of too strong reagent ions to the ion detector. The sensitivity can be improved by about 5 times for sample molecules ionized by traditional photo ionization energy, such as toluene, with ionization energy lower than photon energy.

The invention discloses an in-vitro unknown drug photoionization mass spectrometry rapid qualitative analysis method, which comprises: S1, dissolving a captured suspected drug sample in an acetone or methanol solution, taking out the supernatant, and transferring into a sample bottle; s2, selecting a polar or non-polar SPME probe to penetrate through the sample bottle isolation pad to be inserted into the sample bottle isolation pad, and extracting; and S3, inserting the probe tube into the sample inlet, pushing the handle rod, extending out of the probe extraction head, and performing thermal desorption to desorb the sample to be detected and enter a mass spectrum ionization area. According to the method, richer ionized ion fragment information and molecular ions are provided in the rapid qualitative analysis and accurate identification process of on-site investigation of drugs and precursor chemicals by using a miniaturized mass spectrum technology, and molecular structure information can be provided for analyzing chemical components of unknown novel drugs by using a compound mass spectrum library.

The invention relates to an ion mobility spectrometry for switching ion types of a photo ionization reagent by controlling air pressure. The ion mobility spectrometry comprises a photo ionization ion mobility spectrometry, a reagent ion generating device and an air pressure control device, reagent molecule acetone is brought into the ionization area through carrier gas after being volatilized in a reagent bottle in a headspace mode, a mechanical pump is externally connected to a tail gas outlet of the migration tube so as to reduce the working air pressure in the migration tube, the reading is read through a barometer, and the content of carbon dioxide in the migration tube and the collision probability between ions are reduced. At normal pressure, the main reagent ion in the negative ion mode is CO3-(H2O) n, and at low pressure, the generation of CO3-(H2O) n is inhibited, and the main reagent ion is O2-(H2O) n. O2-(H2O) n is an active ion in a photoionization system, so that the reaction activity can be enhanced, and the detection sensitivity of target product ions, such as methyl salicylate, which is only subjected to an addition reaction with O2-(H2O) n so as to be ionized, is greatly improved. In addition, the method only needs to be externally connected with a mechanical pump to realize pneumatic control, is simple to operate, and does not need to reprocess and design the mobility spectrometry. And the air pressure is changed, so that a relatively high response speed can be realized, and the purpose of quickly switching main reagent ions in a negative ion mode is achieved.

This invention discloses an electrospray extraction / photoionization composite ion source for atmospheric pressure interface mass spectrometry, belonging to the field of mass spectrometry detection. It includes a sample transport and ionization mechanism, an extraction electrospray mechanism, and a vacuum ultraviolet light source mechanism. The extraction electrospray mechanism is fixedly connected to the sample transport and ionization mechanism, and the sample transport and ionization mechanism is fixedly connected to the vacuum ultraviolet light source mechanism. This invention utilizes the aforementioned electrospray extraction / photoionization composite ion source for atmospheric pressure interface mass spectrometry, enabling efficient ionization of gaseous and particulate organic components of different polarities, volatility, and molecular weights in the air. Through a reasonable structural design, it can operate under atmospheric pressure conditions, achieving the purpose of coupling with atmospheric pressure interface mass spectrometry.

The invention discloses a desorption electrospray and secondary photoionization mass spectrometry imaging device combined with an ion funnel, which comprises a double-light-source secondary ionization component, a two-stage ion funnel, a desorption electrospray ionization source and a three-degree-of-freedom displacement imaging platform for carrying a glass slide of a measured object, the desorption electrospray ionization source is arranged above the three-degree-of-freedom displacement imaging platform and located on one side of the glass slide, an electrospray sampling pipe for sampling molecule-ion droplet clusters is arranged at an inlet of the double-light-source secondary ionization assembly, and the electrospray sampling pipe is arranged above the three-degree-of-freedom displacement imaging platform and located on the other side of the glass slide; an outlet of the double-light-source secondary ionization assembly is connected with an inlet of the two-stage ion funnel, and an outlet of the two-stage ion funnel is externally connected with mass spectrometry equipment. Through the integrated design of double-light-source same-cavity secondary ionization, gas phase doping and the two-stage ion funnel, the ionization efficiency and the ion transmission efficiency of the to-be-analyzed object can be remarkably improved.

This invention provides a method and related equipment for measuring molecular beam density, applied to a molecular beam density measurement system. The system includes a vacuum chamber, a precision leak valve, a vacuum ion gauge, a microchannel plate detector, and a laser ionization device. The method includes: controlling the opening of the precision leak valve to introduce background gas into the vacuum chamber and obtaining the standard density of the background gas; photoionizing the background gas and acquiring a first ion signal through the microchannel plate detector; establishing a quantitative calibration relationship between the first ion signal and the standard density; maintaining the operating parameters of the laser ionization device consistent with those used when establishing the quantitative calibration relationship, controlling the laser ionization device to photoionize the target molecular beam and acquiring a second ion signal generated by the target molecular beam; and calculating the absolute density of the target molecular beam based on the second ion signal using the quantitative calibration relationship. This application can improve the accuracy of molecular beam density measurement by introducing a standard gas of known density to establish a quantitative calibration relationship.

The invention relates to the technical field of mass spectrometry instruments, in particular to an oxygen atom induced dissociation device and method based on a photoionization source. The device comprises a sample introduction capillary tube, an ionization source cavity, a repulsion electrode, a vacuum ultraviolet deuterium lamp, a transmission electrode group and a differential electrode, the repulsion electrode, the transmission electrode group and the differential electrode are sequentially arranged in the ionization source cavity in parallel at intervals, and the vacuum ultraviolet deuterium lamp penetrates through the ionization source cavity and then extends into an area between the repulsion electrode and the transmission electrode group; the sample introduction capillary tube sequentially penetrates through the left side wall of the ionization source cavity and a center hole of the repulsion electrode, and the outlet end of the sample introduction capillary tube is located in an area between the repulsion electrode and the transmission electrode group; and direct-current voltage is applied to the repulsion electrode, the transmission electrode group and the differential electrode. By utilizing the characteristics of vacuum ultraviolet light, the photoionization source can generate oxygen atom-induced dissociation reaction in situ, so that the technical threshold and cost are reduced, and convenient switching between two modes of soft ionization and rich structure information is realized.

This invention discloses a photoionization ion migration tube with tunable reactant ions. The ion migration tube contains a first ionization region, a second ionization region, and a third ionization region placed adjacent to each other from left to right. The first ionization region is for initial electron generation and ultraviolet light transmission path control; the second ionization region is for reactant ion generation; and the third ionization region is for the ionization of the sample to be tested. By rapidly switching the concentration of the dopant reagent in the first ionization region, different reactant ions can be rapidly switched and generated with high purity in the second ionization region. Utilizing the differences in the reaction selectivity of different reactant ions, highly selective detection of the sample to be tested can be achieved. Alternatively, by utilizing the differences in the product ions formed by different reactant ions and the sample to be tested, more one-dimensional information can be provided for the qualitative and quantitative analysis of the sample to be tested.

The invention discloses a method for testing blood concentration of cyclopofol based on thermal desorption-photoionization ion mobility spectrometry, which comprises the following steps: detecting the concentration of cyclopofol by using a thermal desorption sampler and a photoionization ion mobility spectrometer, and taking acetone or butanone as a photoionization dopant; the method comprises the following steps: selecting a combined solvent in a thermal desorption sample injector for online extraction and separation of cyclopofol in a to-be-detected sample, preparing a cyclopofol standard substance with gradient concentration, and carrying out qualitative and quantitative analysis on the cyclopofol standard substance in a negative ion high-pressure mode of a thermal desorption-photoionization ion mobility spectrometer; the method comprises the following steps: respectively and continuously accumulating and recording cyclopofol spectrum peak ion mobility spectrometry spectrograms acquired by different cyclopofol concentrations, and fitting a standard curve equation between a target sample concentration and a cyclopofol monomer spectrum peak double-peak signal peak area to realize high-sensitivity and accurate analysis of cyclopofol in blood. The method is simple, rapid and sensitive, automatic analysis of an analyzer can be realized, and the ion mobility spectrometry technology can be more accurately used for measuring the blood concentration of cyclopofol.

The present invention discloses an underexpanded jet vacuum ultraviolet photoionization source, comprising an inlet pipe, a coaxial injector, a vacuum ultraviolet light source, an underexpanded jet ionizer, an insulating exhaust ring, a focusing differential electrode, an insulating ring, a cavity, and a vacuum pump assembly. Sample gas enters the coaxial injector through the inlet pipe and is smoothly and coaxially introduced into the underexpanded jet ionizer. In the high-pressure ionization zone of the underexpanded jet ionizer, the sample gas is ionized into ions by vacuum ultraviolet light. After passing through a sonic velocity limiting orifice, the ions enter a low-pressure scattering zone. Under the action of the underexpanded jet in the scattering zone and the focusing electric field between the ionizer and the focusing differential electrode, the ions are rapidly and focusedly transmitted into a post-stage vacuum. Excess gas is pumped out by the vacuum pump assembly through the insulating exhaust ring. This ionization source overcomes the problems of shock wave interference generated by traditional jet technology and collision-induced dissociation generated by radio frequency transmission technology, effectively improving ion transmission under high pressure.

The invention belongs to the technical field of analytical chemical instruments, and particularly relates to a time-resolved flash decomposition time-of-flight mass spectrometry device. The device comprises a supporting structure, a vacuum cavity, a reaction tank assembly and a time-of-flight mass spectrum. Reactants are loaded into the flow tube reactor through a straight tube; laser emitted by an external trigger laser device is shot into the reactor from a CF63 observation window on one side, and a precursor in the reactor is photolyzed to generate free radicals which react with gas in a tube; reacted gas molecules are sampled by a sampling micropore in the center of the flow tube and a sampling nozzle, and molecular beams are introduced into a photoionization chamber and are ionized by vacuum ultraviolet light emitted by a vacuum ultraviolet discharge lamp; ionized ions are detected by time-of-flight mass spectrometry. The synchronous control module coordinates the photolysis laser and the mass spectrum sampling system, and triggers acquisition of multiple groups of mass spectrum data at preset time intervals in a single photolysis process, so that a time resolution effect is achieved, product information at different time points in single photolysis is obtained, and a powerful experimental means is provided for free radical reaction kinetics research.

The invention relates to the technical field of mass spectrometry instruments, in particular to a photoionization source integrated with a filamentous ion guider. Comprising an ionization source cavity, a vacuum ultraviolet lamp, a repulsion electrode and a filamentous ion guider, wherein the vacuum ultraviolet lamp, the repulsion electrode and the filamentous ion guider are arranged in the ionization source cavity from top to bottom; an ion output port is formed in the bottom of the ionization source cavity; photons emitted by the vacuum ultraviolet lamp sequentially pass through the repulsion electrode and the filamentous ion guider and then are output from the ion output port. The filamentous ion guider comprises a support frame and a plurality of filamentous electrodes which are arranged on the support frame at intervals along the circumferential direction; the plurality of filamentous electrodes are enclosed to form a conical ion focusing transmission channel of which the inner diameter is gradually reduced along the photon emitting direction; dC voltage is applied to the repulsion electrode, and radio frequency voltage is applied to the wire electrode. According to the invention, the surface area of collision between photons and the electrode is greatly reduced, so that the photoelectron yield is reduced, complex side reactions are avoided, and the purity of single-photon ionization is ensured.

The present application relates to mass spectrometry instrument, specifically to a kind of partition non-uniform field photoionization and / or photochemical ionization source device that can realize reagent sufficient ionization, including ultraviolet light source, ion repulsion electrode, isolation electrode, ion transmission electrode, ion focusing electrode, ion source outlet electrode, sample introduction capillary, side extraction valve and ion source cavity;Ion repulsion electrode, isolation electrode, ion transmission electrode, ion focusing electrode and ion source outlet electrode are placed in parallel, insulated, coaxial in ion source cavity, wherein isolation electrode and ion focusing electrode divide ionization zone into three chambers, respectively reagent ion generation zone, ion molecular reaction zone and ion focusing zone. By changing the electric field intensity of reagent ion generation zone, the rapid switching of photoionization or photochemical ionization can be realized. The isolation electrode is a convex electrode with a central through hole and an edge thickness of 1-10 mm. By increasing the thickness of the isolation electrode and appropriately reducing the size of the central through hole, the influence of sample gas backflow on the ionization process of reagent molecules can be effectively avoided. Secondly, one or more ion transmission electrodes are added in the reagent ion generation zone, which can make the reagent molecules fully photoionize, produce high-intensity and high-purity reagent ions, and thus effectively improve the sensitivity of the analyte analysis. The device can be used with any type of mass analyzer to achieve high-sensitivity and rapid detection of various trace volatile components.

The invention relates to the technical field of mass spectrometry instruments, in particular to a device for improving the detection sensitivity of a photo ionization source in a low-pressure environment, which comprises a sample introduction tube, an ionization source cavity, a vacuum ultraviolet lamp, a repulsion electrode, a gas supplementing capillary tube, an inert gas source and an ion funnel, and the other end of the gas supplementing capillary tube penetrates into the ionization source cavity and extends to a position between the repulsion electrode and the ion funnel. The detection sensitivity of the photoionization source in the low-pressure environment can be improved under the condition that the sample injection amount is not increased, the ionization source cavity can inject samples from the low-pressure environment, and high-purity inert gas is introduced through the gas supplementing capillary tube. The air pressure in the ionization source cavity can be maintained within the air pressure range where the ion funnel can work efficiently, efficient transmission of sample ions in the source is achieved, and the detection sensitivity of an instrument is greatly improved.

The present invention discloses an adjustable photoionization sensor, characterized in that the adjustable photoionization sensor includes: an ultraviolet lamp, a light source baffle, an ionization chamber, and an amplifier circuit; the ultraviolet lamp includes a light source outlet for emitting ultraviolet light; one side of the light source baffle is connected to the light source outlet, and the light source baffle is used to block part of the ultraviolet light; the ionization chamber is connected to the other side of the light source baffle, and the ionization chamber is used to ionize gas in the ionization chamber by ultraviolet light; one end of the amplifier circuit is connected to one end of the ionization chamber, and the other end of the amplifier circuit outputs an amplified signal. The adjustable photoionization sensor of the present invention achieves the effect of changing the ionized gas volume without disassembly or replacement of components through the blocking effect of the light source baffle, thereby changing the gas ion current under the same gas concentration, and further changing the gas concentration measurement range.

A self-testing photoionisation detector (PID) 200 for determining the concentration of a gaseous compound, comprises; a gas ionisation chamber 206 for receiving the gaseous compound; an ultraviolet lamp 203 configured to ionise the gaseous compound within the gas ionisation chamber; an output sensor 204 configured to produce an output electrical signal that correlates to an ionic current within the gas ionisation chamber; and a control unit 209 configured to generate a control electrical signal 201 for driving the ultraviolet lamp, to increase or decrease the control electrical signal and provide a user alert electrical signal is provided in the absence of a correlation between the control electrical signal or any change in the control electrical signal and the output electrical signal or any change in the output electrical signal, respectively.

The invention discloses a mobile sampling time-of-flight mass spectrometry detection device and application, and belongs to the technical field of mass spectrometry. The device comprises a reaction tube, a sleeve, a moving mechanism, a grading air exhaust mechanism, a photoionization chamber and a reflective time-of-flight mass spectrometer, wherein the wall surface of the reaction tube is provided with multiple axial sampling areas; the sleeve is sleeved outside the reaction tube; the side wall of the sleeve is provided with a quartz nozzle; during working, the moving mechanism drives the sleeve to enable the quartz nozzle to be aligned with a sampling area, gas forms an ultrasonic molecular beam through the funnel, neutral molecules are ionized by the light source after graded gas extraction and pressure reduction, and ions are analyzed by the mass spectrometer. The device is used for research on product selectivity and reaction mechanism by spatial distribution of short-chain olefin prepared by Fischer-Tropsch synthesis, isomeride can be distinguished, axial species distribution can be accurately represented, and detection selectivity and reliability can be improved.

The invention provides a distiller's yeast quality grade identification method based on a thermal desorption-photoionization ion migration electronic nose system. The method comprises the following steps: firstly, enriching and concentrating distiller's yeast volatile matters and efficiently removing moisture through a thermal desorption module; then carrying out millisecond-level separation detection on trace characteristic components by adopting a photoionization ion migration electronic nose, wherein a distiller's yeast characteristic fingerprint spectrum can be accurately captured by virtue of a ppb-level detection limit of the photoionization ion migration electronic nose; and finally, an SVM algorithm is integrated, an accurate distiller's yeast quality grade discrimination model is constructed, and intelligent classification of distiller's yeast quality grades is realized. Actual sample verification shows that the method can complete distiller's yeast grade identification within 3 minutes, has high goodness of fit with evaluation results of sensory experts in the industry, and provides a new quality control normal form integrating rapid detection, intelligent analysis and process monitoring for white spirit production.

The present invention relates to the technical field of mass spectrometers, and in particular to an electrospray photoionization composite ionization source. It includes a vacuum ionization source cavity, an ion transmission system, an ion extraction electrode, a sensing electrode and a spray capillary array group, wherein the interior of the vacuum ionization source cavity is provided with a spray capillary array group, an ion transmission system and an ion extraction electrode from left to right in sequence, and the sensing electrode is arranged on the outside of the spray capillary array group, and is used to apply voltage to the sample, and the sample is sprayed and ionized to obtain ions; the ion transmission system includes a plurality of transmission electrodes arranged at intervals, and each transmission electrode is provided with a miniature ultraviolet light source, and non-polar neutral molecules that are not sprayed and ionized by the sensing electrode are ionized under the irradiation of the miniature ultraviolet light source, and the ions are output by the ion extraction electrode. The present invention improves the detection sample flux, combines the pulse-induced electrode application method and the miniature ultraviolet light source, and improves the ionization efficiency, ion utilization rate and ionization coverage.