23 results about "Photo ionization" patented technology

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.

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.

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 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 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 belongs to the technical field of mass spectrum analyzers, and particularly relates to a radial sample injection magnetic enhancement photoelectron ionization source device, one side of an ionization source cavity is provided with a sample injection interface, the opposite side is provided with a hole electrode, and the ionization source cavity is internally provided with a magnetic enhancement photoelectron ionization area and an ion funnel transmission area; the repulsion electrode is located between one side of the focusing electrode and the sample introduction interface, and an ion funnel transmission area is arranged between the other side of the focusing electrode and the hole electrode; a focusing electrode is arranged on the ionization source cavity, a vacuum ultraviolet light source is arranged on the ionization source cavity corresponding to the focusing electrode, a magnet A and a magnet B are respectively arranged above and below the focusing electrode, the magnet A is positioned between the vacuum ultraviolet light source and the focusing electrode, a photoelectric cathode is arranged on the magnet B, and light of the vacuum ultraviolet light source is irradiated on the photoelectric cathode after passing through the magnet A and the focusing electrode. According to the invention, the detectable object range of the photoionization source is widened, and the sensitivity of an analyte is remarkably improved.

The application discloses a mobile sampling time-of-flight mass spectrometry detection device and application, and belongs to the technical field of mass spectrometry analysis. The device comprises the following: a reaction tube with an axial multi-sampling area, a sleeve pipe sleeved outside the reaction tube and provided with a quartz nozzle on the side wall, a moving mechanism for driving the sleeve pipe to move axially, a staged pumping mechanism comprising a funnel and a multi-stage turbo pump, a photoionization chamber provided with a synchrotron radiation vacuum ultraviolet light source, and a reflection type time-of-flight mass spectrometer. When working, the moving mechanism drives the sleeve pipe so that the quartz nozzle is aligned with the sampling area, gas forms an ultrasonic molecular beam through the funnel, neutral molecules are ionized by the light source after pressure reduction through the staged pumping, and the mass spectrometer analyzes ions. The device is used for researching spatial distribution of short-chain olefins prepared through Fischer-Tropsch synthesis, product selectivity and reaction mechanism, can distinguish isomers, accurately characterizes axial species distribution, and improves detection selectivity and reliability.

A leak detection system includes a chamber support including a chamber supported by a frame. A trace gas supply supplies a trace gas mixture to a first volume defined between the chamber and a test part. A test part support includes an adapter supported by a frame and configured to mate with the test part and to define a second volume between the test part and the adapter. A seal plate surrounds the adapter and seals with the chamber. One or more inlets are in fluid communication with the second volume. N outlets are in fluid communication with the second volume. N fans create a second vacuum pressure in the second volume, supply gas to the one or more inlets and receive gas from a respective one of the N outlets. N gas sensors sense trace gas in the gas received from a respective one of the N outlets.

The application discloses a sampling tube array VUV photoionization source for mass spectrometry, comprising a large-flow sampling port, an array VUV light source sampling tube, a VUV light source, an ion transmission cavity, an ion transmission electrode, an ion extraction electrode and a gas suction pump. Since the sensitivity of the VUV photoionization source is closely related to the sample amount and sample utilization, in order to improve the sensitivity of the VUV photoionization source, the sample amount and sample utilization can be increased. The application designs a sampling tube array VUV photoionization source, which combines the VUV light source and the sampling tube in a clever way, so that the sample can be effectively irradiated by the VUV light source during the transmission of the sampling tube, thereby improving the sample utilization and the sample ionization efficiency, and achieving the purpose of VOCs detection sensitivity. In addition, a large-flow sampling port is adopted, so as to improve the accuracy of the sampling concentration. The application can effectively improve the detection sensitivity and accuracy of the mass spectrometer for gas samples, and has a wide application prospect in the technical field of VOCs detection such as rapid atmospheric environment monitoring and industrial process online monitoring.

The invention discloses an analysis method for evaluating the peak separation performance of an ion mobility spectrometer. The analysis method comprises the following steps: analyzing a standard sample by adopting an ion mobility spectrometry in a direct photo ionization mode; the standard sample is a headspace gas of an acetone-butanone mixed test solution; the method comprises the following steps: 1, peak separation in a positive ion mode: forming an acetone dimer peak, an acetone-butanone composite peak and a butanone dimer peak, reading migration time and half-peak width of the acetone-butanone composite peak and the butanone dimer peak, and calculating to obtain a separation degree R positive; step 2, performing peak separation in a negative ion mode: forming a CO3 <-> ion peak and an O2 <-> ion peak, reading the migration time and the half-peak width of the CO3 <-> ion peak and the O2 <-> ion peak, and performing calculation to obtain the separation degree R < negative >. When R is greater than or equal to 1.5, two adjacent peaks reach baseline separation and are not overlapped; when R is more than or equal to 1.0 and less than 1.5, overlapping of two adjacent peaks is less than or equal to 5%, and the method is suitable for simple sample analysis; when R is less than 1.0, overlapping of two adjacent peaks is more than 5%, and quantitative analysis of samples is difficult.

The application discloses a mass spectrum ionization source device for high-boiling-point compound detection and belongs to the technical field of mass spectrum analyzers.The device comprises an ionization device, a heating device, a heat preservation device and a detection device.The heating rod is directly inserted into the stainless steel electrode in the ionization source, the ionization source can be rapidly heated to a high temperature without affecting the vacuum of the ionization source, the method is reliable, the installation is simple, the problems of residue and adsorption of high-boiling-point compounds are solved, and the range of ionizable compounds of photoionization mass spectrum is greatly widened.

A vacuum ultraviolet photoionization-photochemical ionization combined ionization source comprises an ionization source cavity and a vacuum ultraviolet light source, the ionization source cavity is a hollow closed cavity, a lamp head repulsion electrode, a radio frequency coupling electrode, a photoelectron emission grid electrode, an ionization zone transmission electrode, an ionization zone ion guide electrode and an ionization zone exit grid electrode are arranged in the ionization source cavity; a circular light shielding electrode is arranged at a middle position of the ion guide zone, the light shielding electrode is a flat plate electrode, and the outer diameter of the light shielding electrode is smaller than the inner diameter of the ion through hole of the ionization zone ion guide electrode. The application realizes efficient vacuum ultraviolet photoionization and photochemical ionization based on a single VUV light source, can effectively widen the range of samples that can be detected by a photoionization mass spectrometer, improves the detection sensitivity of the instrument, and has wide application prospects in the fields of atmospheric environment detection, industrial process monitoring and high-throughput analysis of metabolites.

The application discloses a method for reducing the matrix effect of photoionization ion mobility spectrometry for detecting complex samples. The ion mobility spectrometer comprises an ion mobility tube with good air tightness, a photoionization source and an ion receiving electrode oppositely arranged at the left and right ends of the ion mobility tube, and an ion gate between the photoionization source and the ion receiving electrode. The region between the photoionization source and the ion gate is an ionization zone, and the region between the ion gate and the ion receiving electrode is a migration zone. The method maintains the air pressure in the ion mobility tube in the range of 10-80 kPa, and at the same time, adjusts the isolated high-voltage power supply connected with the ionization zone to maintain the electric field in the ionization zone in the range of 300-600 V / cm, so that the ion-molecule reactions such as charge transfer and proton transfer of the ionized complex target compound in the ionization zone are inhibited, thereby being beneficial to eliminating the influence of the complex matrix on the accurate quantification and detection of the ion mobility spectrometer for low proton affinity or high ionization energy target compounds.

An ion mobility spectrometry method that switches the type of photoionized reagent ions by controlling gas pressure includes a photoionization ion mobility spectrometer, a reagent ion generator, and a gas pressure control device. The reagent molecule acetone evaporates in the headspace of the reagent bottle and is carried into the ionization region by a carrier gas. An external mechanical pump connected to the gas outlet of the migration tube reduces the working gas pressure inside the migration tube, and the pressure is read by a barometer, thus reducing the carbon dioxide content and the probability of collisions between ions within the migration tube. At atmospheric pressure, the main reagent ion in negative ion mode is CO3. ‑ (H2O) n Low pressure inhibits CO3 ‑ (H2O) n It is produced, and the main reagent ion is O2. ‑ (H2O) n O2 ‑ (H2O) n Within a photoionization system, these are active ions, which can enhance reactivity and significantly improve the detection sensitivity of target analytes and product ions. For example, for methyl salicylate, which only reacts with O2... ‑ (H2O) n The target substance undergoes an addition reaction, thereby ionizing. Furthermore, this method only requires an external mechanical pump for pressure control, making it simple to operate and eliminating the need for redesigning the migration spectrum. Changing the pressure also allows for a faster response speed, enabling rapid switching of the primary reagent ion in the negative ion mode.

The invention belongs to the technical field of mass spectrometry instruments, and particularly relates to an HPPI-Orbitrap ion transmission interface. Comprising an HPPI source, an ion transmission cavity and an Orbitrap mass spectrometer which are coaxially arranged in sequence, the HPPI source is connected with the ion transmission cavity, the HPPI source ionizes sample molecules through ultraviolet light to generate sample ions, and the ion transmission cavity is used for transmitting the sample ions; an ion funnel introduction electrode, an ion funnel electrode plate group and an air pressure difference conical opening are sequentially arranged in the ion transmission cavity in the ion transmission direction, the ion funnel electrode plate group comprises a plurality of annular ion funnel electrode plates, and sample ions are introduced into the ion transmission area by the ion funnel introduction electrode; sample ions are transmitted to the air pressure difference conical opening under the action of the radio frequency electric field, and the air pressure difference conical opening transmits the sample ions to the Orbitrap mass spectrometer. The HPPI ionization source and the Orbitrap mass spectrometer are stably coupled, the detection range of the Orbitrap mass spectrometer for weak-polarity and non-polar VOCs is expanded, and meanwhile the detection sensitivity and the qualitative ability are improved by combining the advantages of the HPPI ionization source and the Orbitrap mass spectrometer.

The application provides a method for rapidly detecting VOCs in incineration flue gas by using a photoionization time-of-flight mass spectrometer. The method first establishes a standard curve of each component of VOCs in the incineration flue gas by using the photoionization time-of-flight mass spectrometer, then the photoionization time-of-flight mass spectrometer is used for real-time sampling and detection of the incineration flue gas sample, the sample ions are transmitted to a high-resolution reflective time-of-flight mass analyzer through a radio frequency quadrupole and an electrostatic ion transmission system, and are separated and detected according to the time-of-flight difference to the detector. The mass spectrum of each component of VOCs in the detected incineration flue gas is compared with the mass spectrum of the standard gas of each component of VOCs in the incineration flue gas, and the actual concentration of each component of VOCs in the incineration flue gas is calculated according to the standard curve of each component of VOCs in the incineration flue gas. The method can realize high-sensitivity, high-accuracy and full-coverage online monitoring of VOCs in the flue gas in the industrial incineration site, does not need to collect, purify, concentrate and other steps for the flue gas sample, and can realize real-time feedback of VOCs in the incineration flue gas.

The invention relates to a photoionization light intensity selectable quadrupole mass spectrometer and a use method thereof. The photoionization light intensity selectable quadrupole mass spectrometer comprises a light source cavity, a main cavity, a quadrupole mass analyzer, a photomultiplier, a molecular pump and a light intensity selection assembly. The light intensity selection assembly is used for selecting light intensity; the main cavity comprises an ionization chamber and an analysis chamber, an ion collimating lens for focusing ions formed by ionization is mounted in the ionization chamber, and the focused ions enter the analysis chamber through a through hole; the quadrupole rod mass analyzer is used for screening ions with different mass-to-charge ratios and sending the ions into the photomultiplier, the photomultiplier is used for amplifying an ion current signal and sending the ion current signal to the processor for processing, and the processor is used for detecting gas to be detected. The light intensity of the light beam entering the ionization chamber is selected through the light intensity selection assembly, flexible selection of the light intensity of photoionization is achieved, the complex operation of light intensity selection of a traditional photoionization mass spectrum system is greatly optimized, and the working efficiency of the mass spectrum system is greatly improved.

The application discloses a large-space VOCs detection photoionization source for mass spectrometry, comprising an ionization source cavity, a sample sampling port, a VUV light source, an array VUV light source fixing electrode, an ion transmission electrode, an ion extraction electrode and a radio frequency power supply system. Since the sensitivity of the mass spectrometry ionization source is closely related to sample utilization, in order to improve the sensitivity of the ionization source, the sample ionization space can be increased. The VUV light source is designed in a large-space array, which on the one hand increases the ionization space, improves the sample utilization, and on the other hand increases the residence time, improves the sample ionization efficiency; in addition, the radio frequency electric field is introduced into the ionization source, and the ions generated in the large ionization space are converged, so that the sensitivity of VOCs detection is finally improved. The application can effectively improve the detection sensitivity of the mass spectrometer to VOCs, and has a wide application prospect in the technical field of VOCs detection in atmospheric environment, industrial process, medical diagnosis and the like.

A photoionization sensor assembly includes a housing defining a chamber having a first end and an opposing second end, the chamber being permeable to both analyte and nonanalyte gases. A radiation source is configured to emit photons into the chamber. First, second, and third electrodes are located within the chamber. Photons ionize the analyte gas, but not enough to ionize the nonanalyte gas, and cause photoelectrons to be emitted from the third electrode. A controller is configured to receive a measurement of total pressure and electrically bias the electrodes to collect photoelectrons on the first and second electrodes at a ratio dependent on the total pressure. The controller is configured to determine the ratio of photoelectrons collected on the first and second electrodes at the total pressure and to determine the amount of current due to ionization by correcting a measured current using the determined ratio.