47 results about "Chemical ionization" patented technology

The invention discloses an ion molecule reaction tube with a magnetic focusing structure and an ion focusing method thereof, and belongs to the field of analysis and detection.The ion molecule reaction tube comprises an ionization source, a left ion inlet electrode, a plurality of traditional circular ring electrodes, a right ion outlet electrode, a reaction tube inner focusing magnetic pole and a reaction tube outer focusing magnetic pole; a hole is formed in the center of the focusing magnetic pole in the reaction tube, the left side surface of the hole is covered by the magnetic net, and the right side is open; a hole is formed in the center of the focusing magnetic pole outside the reaction tube, and the left and right sides are open; the left-side ion inlet electrode, the plurality of traditional circular ring electrodes and the right-side ion outlet electrode are separated by insulating sealing gaskets to form a hollow reaction tube cavity; according to the ion focusing method, focusing guide magnetic fields are formed on the left side of a focusing magnetic pole in a reaction tube and between the focusing magnetic pole and an ion outlet electrode on the right side in the reaction tube, and product ions can be gradually and efficiently focused and guided. The method has an important value for improving the detection sensitivity of the chemical ionization mass spectrometer.

The invention belongs to the technical field of mass spectrum ionization sources, provides a tandem mass spectrum ionization source for online detection of disease markers in tail end gas of expired gas of a human body, and aims to solve the problems of complex expired gas sampling, insufficient detection sensitivity and difficult real-time monitoring in the prior art. According to the ionization source device, real-time online expiration analysis of expired gas of a human body can be achieved, the expired gas end gas moment can be determined according to the change of the concentration of carbon dioxide in the expired gas, and therefore real-time analysis of disease markers in the expired gas end gas is achieved. According to the technical scheme, the design that double ionization sources are connected in series is adopted, and a funnel-shaped chemical ionization source is arranged at the front end and specially used for high-sensitivity detection of volatile organic compounds in exhaled air; the photoelectron ionization source is arranged at the rear end and used for monitoring the carbon dioxide concentration in real time and determining the end gas moment. According to the design, high sensitivity of organic matter detection and accurate monitoring of carbon dioxide concentration are both considered in a partitioned ionization mode. The efficient, sensitive and reliable mass spectrum ionization source device is provided for exhaled gas detection, automatic distinguishing of the front end and the tail end of exhaled gas and high-sensitivity analysis of disease markers in tail end gas can be achieved, the sampling process can be simplified, the detection efficiency can be improved, and the mass spectrum ionization source device has wide application prospects, can be suitable for various scenes and has wide application prospects. The method includes clinical disease early diagnosis, health monitoring and the like.

The invention relates to a method for trace analytical detection and quantification of compounds of boron and / or aluminium in a gas or liquid flow containing at least one chlorosilane, comprising the steps of a) removing a sample from the gas flow and mixing with an inert gas to form a gaseous sample or removing a liquid sample from the liquid flow, wherein the liquid sample is mixed with an inert gas in an evaporator unit and evaporated to form a gaseous sample; b) transferring the gaseous sample obtained in step a) into the reaction chamber of a mass spectrometer, wherein electrons generated in an ion source by means of plasma discharge react with the chlorosilane to form chloride ion species and wherein the chloride ion species react with the compounds of boron and / or aluminum via chemical ionization to form boron and / or aluminum chloride ion species; c) separating and detecting the boron and / or aluminum chloride ion species.

The application discloses a chemical ionization mass spectrometry environment humidity correction method based on functional group classification, and comprises the following steps: establishing a humidity-mass spectrometry sensitivity dataset of different functional group species; based on the humidity-mass spectrometry sensitivity dataset, a humidity-mass spectrometry sensitivity data correction equation based on machine learning functional group classification is established; and the actual mass spectrometry sensitivity of a target species under current environmental humidity conditions is calculated according to the humidity-mass spectrometry sensitivity data correction equation. The application acquires the mass spectrometry sensitivity response characteristics of different functional group species under different environmental humidity conditions, constructs a classified humidity-mass spectrometry sensitivity data correction equation, effectively reduces the uncertainty caused by humidity changes on the mass spectrometry quantitative results of semi-volatile organic substances, improves the accuracy and stability of quantitative analysis under different humidity conditions, and solves the problem that the humidity influence is not effectively considered or only a single humidity correction method is adopted in the prior art, resulting in insufficient applicability to multiple functional group species.

The invention discloses a non-target analysis technology based on mass spectrum similarity, differential spectrum distribution and time-dependent hierarchical clustering analysis (HCA), is used for analyzing time-dependent mass spectrum data obtained by direct sample introduction of a high-resolution flight time chemical ionization mass spectrometer and realizing rapid identification of volatile components with different white spirit characteristics, and belongs to the technical field of analysis and detection. According to the method, the similarity of volatile components of Baijiu is judged through characteristic included angles between mass spectrograms, and Baijiu with different flavors or different series of Baijiu with the same flavor is qualitatively distinguished; further acquiring species and abundance differences of the volatile components in combination with differential spectrum distribution; the time-dependent HCA method is used for carrying out two-dimensional analysis of time and component latitude on the high-resolution mass spectrum, so that characteristic volatile species of different Baijiu are accurately identified, and efficient and rapid distinguishing and identification of Baijiu brands or aroma types are realized. According to the method, multi-level analysis is carried out on the mass spectrum collected in situ, the mass spectrum difference of different brands or flavors of baijiu is visually displayed, online detection and rapid identification of the volatile components of the baijiu can be achieved, the problem of refined identification of the volatile components of the baijiu is solved, and the method is widely suitable for baijiu quality control, authenticity identification and flavor database construction.

The invention provides a chemical ionization source device based on thermal desorption and a control method, and belongs to the technical field of mass spectrum devices. The device comprises a thermal desorption source, a three-axis moving platform, an analysis plate and an atmospheric pressure ion source, a through hole is formed in the three-axis moving platform, the analysis plate is placed above the three-axis moving platform, a plurality of analysis holes are formed in the analysis plate, at least one analysis hole is aligned to the through hole, a metal alloy supporting plate used for placing a sample is installed in the analysis hole, and the atmospheric pressure ion source is arranged on the metal alloy supporting plate. The thermal desorption source is arranged below the through hole and faces the metal alloy supporting plate, an input port of the atmospheric pressure ion source is provided with a transmission pipe used for inputting gas, the front end of the transmission pipe can be inserted into and cover the analysis hole, and the output end of the atmospheric pressure ion source is used for being connected with a mass spectrometer. According to the chemical ionization source device based on thermal desorption and the control method, operation is easy, a sample can be ionized more efficiently, and therefore the plasma obtaining efficiency is improved, and practicability is good.

The utility model discloses a system for testing VOCs released by a material, and belongs to the technical field of VOC testing. Comprising a bag type environmental chamber, a chemical ionization source and a mass spectrometer, the bag type environmental chamber is communicated with the chemical ionization source, and the chemical ionization source is communicated with the mass spectrometer; the bag type environment chamber comprises a water bath kettle, a bubbling bottle, an environment air bag, a constant temperature box and an auxiliary air bag, the environment air bag and the auxiliary air bag are arranged in the constant temperature box, and the environment air bag is communicated with the auxiliary air bag; the bubbling bottle is arranged in the water bath kettle, the water bath kettle is communicated with the environment air bag, and the environment air bag is communicated with the chemical ionization source. The environment air bag can be cleaned through cooperation of the auxiliary air bag and the constant-temperature box, a new air bag does not need to be replaced, the experiment cost is reduced, and the implementation efficiency is improved; the problems that the mass spectrum analysis efficiency is low and the time resolution of mass spectrum analysis is influenced due to the fact that environment starting is manually replaced are solved.

The application belongs to the technical field of analysis and detection, and relates to a photochemical ionization device for mass spectrometry for real-time online detection of glyoxal in the atmosphere. The photochemical ionization device sequentially arranges a vacuum ultraviolet light source, an oxygen negative reagent ion generation zone and an ion molecule reaction zone according to the emission direction of the vacuum ultraviolet light. The oxygen negative reagent ion generation zone is a straight channel, bias electrodes, a first partial pressure electrode and a second partial pressure electrode are sequentially arranged in the wall of the straight channel according to the emission direction of the vacuum ultraviolet light, the direction of the electric field formed between the bias electrodes, the first partial pressure electrode and the second partial pressure electrode is opposite to the emission direction of the vacuum ultraviolet light, a pump is arranged between the bias electrodes and the first partial pressure electrode, an air source and a reagent auxiliary gas source are connected between the first partial pressure electrode and the second partial pressure electrode, and a gas source containing a target molecule to be detected is connected between the second partial pressure electrode and the ion molecule reaction zone. The application can effectively remove O3 generated by the vacuum ultraviolet light, thereby improving the sensitivity of glyoxal detection.

The invention discloses a double-flight-time two-dimensional rapid separation chemical ionization mass spectrometer and an isomeride separation and detection method thereof, and belongs to the technical field of analysis and detection.The chemical ionization mass spectrometer comprises an ionization source, a reaction tube, a migration tube, a transition cavity and a mass spectrum cavity which are connected through coaxial small holes from left to right; a funnel electrode is arranged in the reaction tube; an ion gate, a guide electrode, a sectional type quadrupole rod guide electrode and a Faraday plate which are coaxially distributed from left to right are arranged in the migration tube; a small hole is formed in the center of the Faraday plate; the reaction tube is connected with a sample introduction pipeline; the transition cavity guide electrode is positioned in the transition cavity; the flight time mass spectrum detector is positioned in the mass spectrum cavity; the transition cavity guide electrode and an ion inlet of the time-of-flight mass spectrometry detector are coaxially distributed; the sectional type quadrupole rod guide electrode is composed of a plurality of sections of quadrupole rods which are distributed coaxially. According to the invention, rapid separation and high-sensitivity detection of the isomeride can be realized.

The invention relates to the technical field of semiconductor preparation, in particular to a semiconductor gaseous molecular pollutant high-coverage detection mass spectrum device and method. The device comprises a quasi-normal-pressure chemical ionization cavity, a differential transmission cavity, a low-pressure chemical ionization cavity and a mass analyzer which are sequentially connected in series, wherein vacuum difference is realized among the cavities through three ion extraction electrodes; the quasi-normal-pressure chemical ionization cavity performs chemical reaction ionization on polar components of sample gas through first reagent ions and transmits the first reagent ions and the polar components of the sample gas; the differential transmission cavity is used for efficiently transmitting the ionized sample; and the low-pressure chemical ionization cavity carries out low-pressure chemical ionization on the non-polar or weak-polar neutral sample which is not ionized through second reagent ions, and the second reagent ions are efficiently transmitted into the mass analyzer for mass spectrometric detection. According to the invention, the coupling of the quasi-normal-pressure chemical ionization source and the low-pressure chemical ionization source is realized through the multi-stage vacuum differential design, so that the non-polar or polar trace AMC compounds in the semiconductor can be detected with high sensitivity and high coverage.

The present invention discloses an ion-molecule reaction device and method for chemical ionization mass spectrometry detection, which belongs to the field of chemical ionization mass spectrometry detection technology, including a reaction body and a tapered end head, a cylindrical cavity is provided in the reaction body, and a tapered rectifier channel with a smooth transition with the cylindrical cavity is provided in the tapered end head; the reaction body is located at the inlet end of the cylindrical cavity and is correspondingly provided with a closed end cap, a tapered cavity corresponding to the cylindrical cavity is provided in the closed end cap, and an electrode for generating an electric field is provided in the circumferential direction of the inner wall of the tapered cavity; a gas-like joint is provided at the center of the top of the closed end cap, and an ion source joint connected to the tapered cavity is provided on one side of the top of the closed end cap. Reagent ions of the present invention can be focused on the axis of the cylindrical cavity and the tapered rectifier channel under the dual action of the electric field and flow field in the ion-molecule reaction device under atmospheric interface pressure, significantly improving the transmission efficiency of reagent ions, and then greatly improving the ion / molecule reaction efficiency.

The invention relates to a method for detecting straight-chain alkane by mass spectrometry based on a VUV lamp, which comprises the following steps: taking a time-of-flight mass spectrum as an analyzer, taking nitrogen dioxide as a reagent molecule of chemical ionization, and enabling to-be-detected gas to enter a mass spectrum ionization source in a negative pressure form through a PEEK capillary tube; meanwhile, nitrogen dioxide gas with the volume concentration of 1% enters a mass spectrum ionization source in a negative pressure form through another PEEK capillary tube, and nitrogen dioxide ions generated by ionizing the nitrogen dioxide gas through a VUV lamp and straight-chain alkane molecules are subjected to a hydrogen abstracting reaction to generate # imgabs0 # ions. According to the method, the defects that the sensitivity of VUV lamp single-photon ionization detection of the straight-chain alkane is not enough and fragmentation is difficult to avoid are overcome, and the qualitative analysis capability of the device on the straight-chain alkane and the signal intensity are improved.

The present disclosure of the invention concerns embodiments directed to a multi-pressure chemical ionization multi-ion identification device (MPCI MION device), a system and method using the same to utilize chemical ionization (CI) in multiple adduct formation from the substances in the sampled gas of a gas sample being addressed to be analyzed in a mass analyzer. The multi-pressure multi-ion identification (MPCI MION) device comprises a buffering region to have the sample flow turbulence decayed before the sample flow entrance to the low pressure ionization regions (IR(A)), IR(B), (IR(B′), (IR(C′), IR(D′)) (IR(E′)) utilizing chemical ionization by reagents from an ensemble of reagent ion towers (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18,).

Generally the embodiments of the present disclosure relate to ion identification-based mass analysis (MS), and more particularly to ionization device (100) and a related ionization device system (100S) being able to use solid reagent material (101) for reagent ion [R(101 )+ / -] formation for a chemical ionization of samples (S) being sampled. Embodiments also concern use of a selected precursor material as for example urea in solid form.

The invention relates to the technical field of mass spectrum analyzers, in particular to a mass spectrum ionization device and method for cooperatively monitoring dirt and carbon. The device comprises a high-pressure photochemical ionization cavity and a low-pressure photoelectron ionization cavity, an ion transmission module and an ion convergence reaction electrode group are arranged in the high-pressure photochemical ionization cavity; organic product ions are generated in the high-pressure photochemical ionization cavity and penetrate through a differential electrode to be transmitted into the low-pressure photoelectron ionization cavity; an electron transmission module, an ion convergence multi-pole rod group and an ion extraction electrode are arranged in the low-pressure photoelectron ionization cavity, the low-pressure photoelectron ionization cavity generates inorganic product ions, and the inorganic product ions and organic product ions penetrate through the ion extraction electrode and are transmitted to the mass analyzer for detection. Cascade connection of the two ion sources under different working air pressures is realized through vacuum difference, so that ionization detection of the two ionization sources can be obtained through single sample introduction, the analysis coverage of a mass spectrometer is greatly improved, and the application field is widened.

The invention discloses a chemical ionization mass spectrometry method for an off-line organic aerosol sample, and aims to realize rapid and accurate measurement of a polar atmospheric organic aerosol sample. The method comprises the following steps: firstly, treating an off-line atmospheric particulate sample, intercepting a sample with the size of 2-7mm, and clamping the sample between two clean filter membranes to fix the sample; then, heating the sample by adopting a nonlinear temperature rising program, and collecting data after heating; a thermal background signal is deducted through a thermal background multiplication method or a thermal background inference method, so that the accuracy of data is ensured; and finally, after hot nitrogen purging desorption, analyzing mass spectrum signals of various organic components of the sample at different temperatures through chemical ionization mass spectrometry to obtain molecular composition information and a thermal desorption curve of compounds in the sample aerosol. The method is simple and convenient to operate, can effectively analyze the chemical components of the polar organic aerosol, is suitable for off-line sample analysis of atmospheric aerosol, and has relatively high popularization and application values.

The present invention relates to the technical field of plasma bioaerosol inactivation, and in particular to a method and apparatus for quantifying the concentration of active particles entering an aerosol. A method for quantifying the concentration of active particles entering an aerosol, comprising the following steps: selecting a carrier that can undergo a physical and chemical reaction with the active particles based on the composition of the active particles. The carrier is then prepared into an aerosol, so that the active particles can enter the aerosol and undergo a series of physical and chemical reactions with the carrier in the aerosol. In this way, the active particles with a short lifespan are converted into products through physical and chemical reactions, and the product is a chemical substance that can be quantitatively measured. The concentration of the product is measured by a chemical ionization mass spectrometer, and then the concentration of the active particles that enter the aerosol and react with the carrier in the aerosol is reversed through the chemical reaction formula in the conversion process, thereby quantifying the concentration of the active particles entering the aerosol.

The apparatus for automatically measuring and monitoring taste and odor-causing substances in water (raw water, purified water, and discharged water) according to an embodiment of the present invention includes: a vaporizing unit which introduces water (raw water, purified water, and discharged water), atomizes the water by using an ultrasonic vibrator, and then sprays the atomized water into a spray chamber, thereby generating an aerosol-type sample; an MS / MS mass spectrometry unit which applies a chemical ionization method using plasma and a quadrupole mass spectrometry (MS / MS) to the aerosol-type sample generated in the vaporization unit to measure mass values of 2-MIB S and Geosmin, which are taste and odor-causing substances; and a quantifying unit which quantifies the mass values of 2-MIB and Geosmin relative to the sample mass, measured by the MS / MS mass spectrometry unit.

The application discloses a method for rapidly detecting butyric acid and isomers thereof in liquor, which does not need any pretreatment process and a large amount of organic solvents, directly takes 0.5-3ml of a liquor sample and adds the sample into a sample bottle of a rapid gas chromatography-PTR photochemical ionization source-time of flight mass spectrometer, selects appropriate rapid gas chromatography mass spectrometry conditions, and utilizes the rapid gas chromatography-PTR photochemical ionization source-time of flight mass spectrometer to rapidly complete detection of butyric acid and isomers thereof in the liquor. The method established by the application does not need any pretreatment process and a large amount of organic solvents, can rapidly detect butyric acid and isomers thereof in the liquor within five minutes, and provides a strong means for acidity and taste adjustment of the liquor.

The application discloses a radio frequency enhanced and convergent ion source for mass spectrometry, comprising a VUV light source, an ion source cavity, an auxiliary gas sampling tube, a push-pull electrode, a lamp electrode, a sample sampling tube, an enhanced reaction zone, an ion convergent zone and an ion extraction electrode. The reagent ion generation method determines the reagent ion species and purity, the molecular ion reaction efficiency and the ion transmission efficiency in the source determine the detection sensitivity of the chemical ionization source. In order to further improve the detection performance of the chemical ionization mass spectrometry, the application designs a radio frequency enhanced and convergent ion source, the reagent ions are generated by the vertical irradiation of the VUV light source, the selection of the reagent ions is facilitated and the influence of photoelectrons can be eliminated; in addition, the radio frequency enhanced reaction zone and the radio frequency ion convergent zone are introduced to improve the molecular ion reaction efficiency and the ion transmission efficiency. The application can effectively improve the detection sensitivity and the universality of the chemical ionization mass spectrometry, and has wide application prospects in the fields of atmospheric environment monitoring, industrial processes, medical diagnosis and the like.

The application discloses a quantitative method for trace gaseous nitrous acid generated by photolysis, which comprises two modes. Mode one uses a chemical ionization mass spectrometer in positive ion mode to measure the concentration change of volatile organic compounds (VOC) reacted with hydroxyl radicals (·OH) after a switch mercury lamp to quantify the ·OH concentration generated by the mercury lamp irradiation, and further makes nitric oxide (NO) react with ·OH to generate gaseous nitrous acid (HONO), so that the generated concentration of HONO is approximately equal to the change concentration of VOC measured by the mass spectrometer under the condition of NO excess. Mode two uses a NO analyzer to measure the concentration change of NO reacted with ·OH before and after the mercury lamp is turned on to quantify HONO and ·OH, and the ·OH concentration generated by the mercury lamp irradiation and the HONO concentration generated under the condition are both approximately equal to the NO concentration change measured by the NO analyzer.

The present disclosure of the invention concerns embodiments directed to a multi-pressure chemical ionization multi-ion identification device (MPCI MION device), a system and method using the same to utilize chemical ionization (CI) in multiple adduct formation from the substances in the sampled gas of a gas sample being addressed to be analyzed in a mass analyzer. The multi-pressure multi-ion identification (MPCI MION) device comprises a buffering region to have the sample flow turbulence decayed before the sample flow entrance to the low pressure ionization regions (IR(A)), IR(B), (IR(B'), (IR(C'), IR(D')) (IR(E')) utilizing chemical ionization by reagents from an ensemble of reagent ion towers (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18,).

The invention discloses a chemical ionization mass spectrum environment humidity correction method based on functional group classification. The method comprises the following steps: establishing humidity-mass spectrum sensitivity data sets of different functional group species; based on the humidity-mass spectrum sensitivity data set, establishing a humidity-mass spectrum sensitivity data correction equation based on machine learning functional group classification; and calculating the actual mass spectrum sensitivity of the target species under the current environment humidity condition according to the humidity-mass spectrum sensitivity data correction equation. According to the method, the mass spectrum sensitivity response characteristics of different functional group species under different environment humidity conditions are obtained, and a classified humidity-mass spectrum sensitivity data correction equation is constructed, so that the uncertainty of a semi-volatile organic compound mass spectrum quantitative result caused by humidity change is effectively reduced; the accuracy and stability of quantitative analysis under different humidity conditions are improved, and the problem that in the prior art, the humidity influence is not effectively considered or only a single humidity correction mode is adopted, so that the applicability to various functional group species is insufficient is solved.

The invention discloses a chemical ionization-differential electromobility screening-mass spectrometry combined system and a working method, and belongs to the technical field of molecular cluster measurement, the chemical ionization-differential electromobility screening-mass spectrometry combined system comprises a normal pressure chemical ionization source system, a planar differential electromobility analyzer, a sheath gas circulation system, an ion transmission interface, an aerosol electrometer, a mass spectrometer and a control system; the chemical ionization source system is connected with the planar differential electromobility analyzer, the planar differential electromobility analyzer and the sheath gas circulation system form a circulation gas path, and the planar differential electromobility analyzer transmits sample ions to be detected to the aerosol electrometer and the mass spectrometer for detection through a special ion transmission interface; the control system is connected with the normal-pressure chemical ionization source system, the planar differential electromobility analyzer, the sheath gas circulation system of the planar differential electromobility analyzer and the mass spectrometer, and provides high voltage and data acquisition, storage and reading. According to the invention, efficient on-line in-situ synchronous monitoring of chemical components and electromobility of gas / molecular clusters in a gas phase can be realized.

The application relates to a radio frequency enhanced photochemical ionization source, which mainly comprises a reagent gas inlet pipe, a sample gas inlet pipe, a gas mixing area, a UVU lamp, a ring-shaped repelling electrode, a ring-shaped focusing electrode, a radio frequency hexapole and a perforated electrode for realizing vacuum difference. The VUV lamp is used as an ionization source, reagent molecules are flexibly selected according to different detection samples, and the universality is good; the collision frequency of reagent ions and sample molecules is increased at low pressure through the radio frequency hexapole, so that the probability of molecular ion reaction is increased, the transmission efficiency of ions is increased through collision focusing, the enhancement of the photochemical ionization source is realized, and the detection sensitivity of the instrument is significantly improved.

This invention discloses an online mass spectrometry analysis device and method for aerosols during the thermal runaway process of lithium-ion batteries, belonging to the field of analytical technology. The device includes a reaction chamber with a reaction cavity inside, in which the lithium-ion battery is placed; a heating jacket for heating the reaction chamber; a chemical ionization source for ionizing the gas output from the outlet pipe; and a mass spectrometer for detecting and analyzing the types and concentrations of ionized ions. A first thermometer and a second thermometer are installed inside the reaction chamber. The first thermometer monitors the temperature inside the reaction cavity, and the second thermometer monitors the temperature of the lithium-ion battery. A pressure gauge is also included to monitor the pressure inside the reaction cavity. This invention enables online, in-situ analysis of aerosols during the thermal runaway process of lithium-ion batteries, obtaining qualitative and quantitative information on a large number of components in the aerosols, solving the problem that existing spectroscopic and sensor technologies are insufficient for analyzing complex components.

The invention discloses a method for synchronously and efficiently monitoring the residual quantity of short-chain and medium-chain chlorinated paraffin in sediment, and relates to the technical field of environmental pollutant analysis. The method comprises the following steps: freeze-drying and grinding a sediment sample, mixing the sediment sample with a stable isotope internal standard, carrying out ultrasonic centrifugal extraction by adopting a dichloromethane and normal hexane mixed solution, and merging supernate; and then, purifying the extract liquor by using a straight-through EMR purification column containing Carbon S, collecting the purified liquor, carrying out nitrogen blowing concentration and solvent replacement, adding a sample introduction internal standard, and carrying out detection in a negative chemical ionization source mode by adopting gas chromatography-quadrupole time-of-flight mass spectrometry. By optimizing the pretreatment process, the dosage of the sample and the solvent is remarkably reduced, and the treatment time is shortened; by combining high-resolution mass spectrometry, the problem that the homologues of the SCCPs and the MCCPs are difficult to separate is effectively solved, synchronous, efficient and accurate quantification of the short-chain chlorinated paraffin and the medium-chain chlorinated paraffin in the sediment is realized, and the recovery rate is high.

The present invention provides a method capable of individually detecting a portion of PAHs and increasing the analysis speed, the method being a method for detecting the presence or absence of predetermined PAHs (molecular formula: M), the method comprising: a step 1 of performing chromatographic separation on a sample containing the PAHs; a step 2-1 of introducing methane gas, ionizing the PAHs by using a chemical ionization method, and generating at least one of [M + CH3] +, [M + C2H5] +, and [M + C3H5] + as a precursor ion, or a step 2-2 of introducing acetonitrile, ionizing the PAHs by using a solvent-mediated chemical ionization method, and generating at least one of [M + CH] +, [M + HNC2] +, and [M + H2NC2] + as a precursor ion; a step 3 for generating fragment ions derived from the precursor ions; and a step 4 of detecting the presence or absence of the PAHs on the basis of the presence or absence of the fragment ions.

The present disclosure relates to a multiple ion identification device, a multiple ion identification system and a method of identifying a substance. The method utilizes chemical ionization (CI) in multiple adducts formed by substances in a sampling gas of a gas sample to be analyzed in a mass spectrometer. The multiple ion identification device comprises a buffer zone to attenuate a sample flow with chemical ionization of reagents from a set of reagent ion towers (R1, R2, R3, R4, R5, R6) before the sample flow enters an ionization region (IR(A)) (IR(B)).

The application discloses a molecular ion reaction cavity for chemical ionization mass spectrometry, which comprises a sampling module, an air inlet module, a reaction module and a power module, the sampling module is provided with a main pipeline and a drainage bypass, the air inlet module is provided with a central hole for fixing a capillary, the reaction module is internally provided with a conical cavity, an ion source air inlet channel is arranged on the side surface close to the top end of the conical cavity, and an air outlet hole is arranged at the center of the bottom surface; sampling gas enters the top end of the conical cavity through the capillary from the main pipeline, reacts with ions entering from the ion source air inlet channel in the conical cavity, and the reacted gas enters a mass spectrometer detector from the air outlet hole; and the power module provides a radial focusing electric field for the conical cavity. The drainage bypass effectively reduces the response time of the reaction cavity to organic matters, the capillary can be replaced according to different experimental conditions, the conical reaction cavity structure effectively reduces ion loss and improves ionization efficiency in a laminar flow state, and the molecular ion reaction process is effectively controlled through an external temperature adjusting device and a vacuum pump.