45 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.

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 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.

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 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 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 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.

This invention discloses a method and related apparatus for determining the Townsend second coefficient in an electrode photoionization corona criterion, belonging to the field of electrode technology. The method determines the ionization region boundary of a conductor during corona initiation using corona initiation voltage, environmental parameters, and the nominal electric field analytical formula. Based on the obtained ionization region boundary, Morrow's ionization coefficient and adhesion coefficient formulas are used to substitute the nominal electric field analytical formula into the photoionization corona criterion, yielding an integral expression for the criterion. The integral interval of the integral expression is discretized, and an initial value is assigned to the Townsend second coefficient. This value is then substituted into the photoionization corona criterion for discretized integral calculation, ultimately obtaining the Townsend second coefficient. This invention can be applied to all AC / DC conductors requiring the use of the photoionization corona criterion, and can determine the Townsend second coefficient of conductor corona initiation under varying conductor geometry, ground elevation, humidity, air pressure, and temperature conditions.

The invention relates to a photoionization detector (PID) lamp assembly and a method of manufacturing a PID lamp assembly. A photo ionization detector (PID) lamp assembly is disclosed. The PID lamp assembly includes a cap defining a lamp chamber therein, and the cap has a stepped aperture. Further, a crystal window is sealed on the cap and configured to allow ultraviolet (UV) light to pass therethrough. In addition, the capillary tube is sealed to the cap via a stepped aperture of the cap. Thereafter, a pair of annular grooves is formed on the cap to mount a pair of driver pads on the cap.

The present application relates to a method for regulating the ion-molecule reaction process in a photoionization source. The method comprises a sample gas, a sample inlet pipeline, a valve, a vacuum ultraviolet light source, an ionization source cavity, an inlet electrode, a light introduction electrode, an outlet electrode and a mass analyzer. The light emitted by the vacuum ultraviolet light source is perpendicular to the axis direction of the light introduction electrode. The range of the vacuum ultraviolet light emitted by the vacuum ultraviolet light source inside the light introduction electrode is the ionization zone. The region between the ionization zone and the outlet electrode constitutes the reaction zone. The sample gas flow q is regulated by the valve to change the ion movement speed v g in the gas flow field; or the voltage difference U applied to the light introduction electrode and the outlet electrode (i.e. the reaction zone) is regulated to change the ion movement speed v d in the electric field; the ion-molecule reaction time in the reaction zone is changed by changing v g and v d , so as to obtain the ion-molecule reaction process or regulate the ion-molecule reaction process.

An online detector for halothane anesthetics in blood uses ion mobility spectrometry as the basic detection technology and combines it with headspace sampling technology to achieve direct analysis of halothane anesthetic concentrations in whole blood without sample pretreatment. The detector consists of a fully automatic headspace sampler, a three-way connector, a variable-diameter sampling sleeve, and a negative ion mode photoionization ion mobility spectrometer. The fully automatic headspace sampler includes a sample carrier, a heating furnace, an injection needle and control components, a six-way valve quantitative loop, and a sample gas transmission tube; the three-way connector is connected to the sample gas transmission tube, the variable-diameter sampling sleeve, and the air purification tube and air respectively. The detection limit of sevoflurane tested by this device and method can reach a concentration below 1 ng / μl, and the detection and analysis time for a single sample is less than 2 minutes. The method of the present invention is intelligent, fast, efficient, and reliable.

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.

A photo-ionization detector (100) and a process detect an ionizable substance in a gas (G). At least two measuring cells (20.1, 20.2, 20.3) are mounted on a measuring cell carrier (10). A radiation source (4) emits ionizing electromagnetic radiation towards the measuring cell carrier (10). The gas (G) reaches at least one measuring cell (20.1, 20.2, 20.3). Ionization of the gas causes a measurable electrical property of the measuring cell (20.1, 20.2, 20.3) to be changed. Depending on the electrical property, the measuring cell (20.1, 20.2, 20.3) generates a signal. This signal correlates with the presence and optionally the concentration of ionizable substance in the gas (G). Preferably, the measuring cell carrier (10) can be rotated relative to the radiation source (4).

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 relates to the technical field of mass spectrometry instruments, in particular to a device for improving the detection sensitivity of a photoionization source in a low-pressure environment, which comprises a sample inlet tube, an ionization source cavity, a vacuum ultraviolet lamp, a push-pull electrode, a gas supplement capillary, an inert gas source and an ion funnel; one end of the gas supplement capillary is connected with the inert gas source; the other end of the gas supplement capillary penetrates into the ionization source cavity and extends to the position between the push-pull electrode and the ion funnel. The device can improve the detection sensitivity of the photoionization source in the low-pressure environment without increasing the sample amount; in addition to the function of sampling from the low-pressure environment, the ionization source cavity also uses the gas supplement capillary to introduce high-purity inert gas, so that the gas pressure in the ionization source cavity can be maintained in the gas pressure range in which the ion funnel can work efficiently, efficient transmission of sample ions in the source is realized, and the detection sensitivity of the instrument is greatly improved.

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.

A photoionization detector comprised of a gas discharge lamp that ionizes molecules of interest to create ionized molecules and electrons and a sensor having at least one opening for UV light to pass through and electrically conductive patterns on at least one of the top and bottom surfaces of the plate, including at least a negative electrical potential pattern and an electron collecting electrode pattern. The ionized molecules are collectable by a bias electrode and electrons are collectable by a collector electrode. The negative electrical potential pattern includes a linear portion and a polarization plate. The electron collecting electrode pattern includes a wire suspended across the at least one opening and a linear portion on the surface opposite the wire. The electrically conductive patterns can further include a grounded potential conductive pattern having a first portion on the top surface and a second portion on the bottom surface.

The chemical ion source comprises a shell, an insulating lining, a vacuum ultraviolet lamp and a photolysis cavity, the lower ends of the shell and the insulating lining are open cylinders, and the upper ends of the shell and the insulating lining are provided with through holes for leading out wires; the shell is sleeved outside the insulating lining, and the vacuum ultraviolet lamp is placed in the insulating lining; the photolysis cavity is in a gyro shape, a cylindrical reaction cavity is formed in the photolysis cavity, an air inlet is formed in the side face of the photolysis cavity, and an outlet is formed in the bottom face of the photolysis cavity and communicated with the reaction cavity; an internal thread is arranged on the lower portion of the shell, an external thread is correspondingly arranged on the upper portion of the photolysis cavity, and the shell and the photolysis cavity are fixedly connected in a rotating mode through the threads. The chemical ion source is based on a vacuum ultraviolet light ionization technology, can realize efficient generation of different reagent ions, can be carried on different chemical ionization mass spectrometers, facilitates replacement of a vacuum ultraviolet lamp, and is very convenient and rapid to use.