A raman-libss-mass spectrometry combined analysis device and analysis method

Abstract

The application belongs to the technical field of chemical detection, and particularly relates to a Raman-LIBS-mass spectrometry combined analysis device and analysis method. The Raman-LIBS-mass spectrometry combined analysis device comprises a multiple-reflection time-of-flight mass spectrometer, a LIBS spectrometer, a Raman spectrometer and a shared module. The shared module comprises a first incident light path system, a second incident light path system, a high-definition observation system, a vacuum sample bin, a vacuum system and a control system. The first incident light path system is used for generating a femtosecond laser beam and performing three-dimensional ablation on a sample. The second incident light path system is used for combining tunable lasers into a resonance ionization light path. Compared with the prior art, the application can realize in-situ micro-area ultra-high resolution element and isotope analysis and imaging, realize ultra-trace element, isotope analysis and isotope ratio analysis under strong matrix interference, and can also perform high-resolution molecular structure and composition analysis and Raman scattering imaging.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical detection, and particularly relates to a Raman-LIBS-mass spectrometry combined analysis device and an analysis method. BACKGROUND

[0002] Isotope technology is used in medical research, nutritional research, and disease diagnosis. In recent years, isotope technology has been increasingly valued in environmental science. Stable isotope abundance changes are used to study and indicate environmental pollution sources and pollution levels, which is important in environmental protection. Laser-induced breakdown spectroscopy (LIBS) and other spectrometers can quickly obtain results when detecting isotopes, but have low sensitivity and limited resolution. For isotopes with very close masses, the resolution may not be sufficient. In stable isotope analysis, mass spectrometry is usually performed on gases, so it is often referred to as a gas mass spectrometer.

[0003] Before isotopic analysis, the sample needs to be prepared into a suitable state for analysis. Mass spectrometers with inductively coupled plasma (ICP) as an ionization source (such as ICP-MS, MC-ICP-MS, ICP-TOF-MS, etc.) are currently the basic instruments for detecting isotopes, but complex pretreatment of the sample is still required. The introduction of strong acids and other substances in the pretreatment process can contaminate the sample and destroy the original state and structure of the sample. At the same time, although the ICP source is mature and stable, the transmission efficiency to the intercepting cone is low after the ICP source generates plasma. All of these can cause great difficulties in detecting low-abundance samples such as young geological samples, and affect the detection results.

[0004] LA-ICP-MS laser ablation inductively coupled plasma mass spectrometer is a laser ablation inductively coupled plasma mass spectrometer that solves the problem of solid sample processing and can perform in-situ micro-area analysis. However, due to the problems of too small sample amount for traditional laser ablation and low ion transmission efficiency, there are still great difficulties in detecting low-abundance isotopes. In addition, researchers in related fields want to determine not only the content of elements and isotopes in the sample, but also the molecular structure and composition analysis of the sample.

[0005] The current element and isotope detection technology has the following limitations: the traditional liquid detection method needs complicated sample pretreatment, introduces pollutants such as strong acid to destroy the original state and structure of the sample, affects the detection accuracy, and cannot realize in-situ micro-area detection, and the result is only an average value; stable isotope analysis (such as C, H, O, N, S) needs to convert the sample into a gas form for mass spectrometry analysis, which limits the detection element range; the isotope abundance is extremely low and the difference is small, and there are problems of isotope fractionation and background interference in detection, which depend on high-sensitivity instruments and method optimization; the ion transmission efficiency of the inductively coupled plasma mass spectrometer (ICP-MS) is low, which limits the detection limit; the traditional laser-induced breakdown spectroscopy (LIBS) is affected by the self-absorption effect, matrix effect and spectral volatility, and has defects such as low detection limit, poor sensitivity and insufficient analysis accuracy; the mass spectrometer is difficult to detect light elements and major elements; the traditional LIBS cannot cover trace elements; the quadrupole mass spectrometer has a mass resolution of only 400~500 Th / Th; and the traditional Raman spectroscopy technology uses a traditional nanosecond laser light source, resulting in weak signal, insufficient sensitivity in low-concentration, trace and trace substance analysis, and difficulty in obtaining effective molecular structure information. SUMMARY

[0006] The technical problem to be solved is as follows:

[0007] The purpose of the present application is to solve at least one of the above problems by providing a Raman-LIBS-mass spectrometry combined analysis device and analysis method, which integrates a three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer, a femtosecond multi-pulse laser-induced breakdown enhanced spectroscopy (LIBS) and a Raman spectrometer, to solve the isobaric interference problem in the prior art, realize ultra-trace element, isotope analysis and isotope ratio analysis under strong matrix interference, realize in-situ micro-area ultra-high resolution element and isotope analysis and imaging, and simultaneously perform high-resolution molecular structure and composition analysis and Raman scattering imaging, which is compact in structure, advanced in technology and high in analysis efficiency.

[0008] The technical scheme is as follows:

[0009] The purpose of the present application is achieved by the following technical scheme:

[0010] The first aspect of the present application discloses a Raman-LIBS-mass spectrometry combined analysis device, comprising a multiple reflection time-of-flight mass spectrometer, a LIBS spectrometer, a Raman spectrometer and a shared module;

[0011] The shared module comprises a first incident light path system, a second incident light path system, a high-definition observation system, a vacuum sample bin, a vacuum system and a control system;

[0012] The first incident light path system comprises a first laser source, a light path shaping assembly and a three-dimensional scanning focusing device arranged in sequence, for generating a femtosecond laser beam and performing three-dimensional ablation on the sample;

[0013] The second incident light path system comprises a second laser source, an independent light path control unit, a light path merging assembly and a focusing unit arranged in sequence, for merging the tunable laser into a resonance ionization light path;

[0014] A plurality of second laser sources are arranged in the second incident light path system, and the second laser sources are tunable lasers with a wavelength tuning range of 210 nm to 4500 nm;

[0015] The independent light path control unit corresponds to the second laser source one by one, and comprises an attenuator and a beam expander arranged in sequence;

[0016] The light path merging assembly comprises a mirror and a beam combiner, for merging multiple laser beams into a single light path;

[0017] The focusing unit comprises a window and a focusing lens, for focusing the merged laser to the sample ablation area.

[0018] The laser beams of the plurality of second laser sources pass through the respective independent light path control units, are merged into a second single light path by the light path merging assembly, and enter the vacuum sample chamber through the focusing unit;

[0019] The multiple reflection time-of-flight mass spectrometer is used for analyzing the content of each element and isotope in the sample and performing element imaging;

[0020] The LIBS spectrometer and the Raman spectrometer respectively collect spectral signals through optical fibers and a light splitting device, analyze the molecular structure and composition of the sample, and perform Raman scattering imaging;

[0021] The multiple reflection time-of-flight mass spectrometer and the LIBS spectrometer share the first incident light path system and the second incident light path system, and the Raman spectrometer takes the first incident light path system as a laser source.

[0022] Further, the control system mainly comprises a computing workstation, a communication module of each component, various sensors, a vacuum gauge, a signal control board and the like, and the collection, processing and sending of information data control the cooperative work of each component.

[0023] Further, the number of working second laser sources can be dynamically adjusted by the control system, and selectively combined and triggered according to the ionization demand of target elements.

[0024] The number of tunable lasers of the second laser source in the second incident light path system is preferably 3, and the tunable lasers can realize a wide tuning range of 210 nm to 4500 nm from ultraviolet to mid-infrared, and high output stability. Since different elements or isotopes have different atomic energy levels, the appropriate laser wavelength, frequency and energy value of each tunable laser are set according to the element or isotope to be measured, so that the energy of the laser photon is resonant with the electron energy level of the target molecule, thereby realizing selective ionization of the substance and enhancing the ionization efficiency of the target atom. According to the target element to be measured, the trigger of the three tunable lasers and the wavelength of the respective output laser are controlled by the control system.

[0025] Further, when the second incident light path system is enabled, at least one second laser source is selected to work.

[0026] Further, the high-definition observation system is a coaxial observation system, mainly composed of a camera, a lens barrel, a beam combining mirror and an objective lens, and shares an objective lens with the first incident light path system. The high-definition observation system is used to observe the sample position, sample state and the condition in the vacuum pool during sample analysis.

[0027] Further, the vacuum sample chamber comprises a three-axis nanometer moving stage, a sample support and a temperature control station, and the vacuum sample chamber is designed to be fully sealed.

[0028] The three-axis nanometer moving stage is installed on the base of the vacuum sample chamber, and is a three-axis nanometer vacuum moving stage with a resolution less than or equal to 10 nm and a repeat positioning accuracy less than or equal to 300 nm.

[0029] The temperature control station is used to accurately control the temperature of the sample, and the control temperature accuracy is 0.1 degrees Celsius.

[0030] The sample support is used to place and fix the sample.

[0031] Further, the multiple reflection time-of-flight mass spectrometer is a three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer, which comprises an interface, an ion transmission system, a multiple reflection time-of-flight mass analyzer and a detector. The first incident light path system and the second incident light path system generate an ion source of the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer.

[0032] The ion transmission system comprises an ion funnel, a curved quadrupole rod, a notch filter, a 90-degree deflection lens and an ion shaping module.

[0033] The curved quadrupole rod functions as an ion guide while removing neutral particles to purify the ion beam.

[0034] The notch filter is used for selectively removing target ions of a specific mass-to-charge ratio (m / z) from an ion beam containing multiple ions, and can selectively remove high-abundance interfering ions.

[0035] The 90-degree deflection lens is used for precisely deflecting the ion beam by 90 degrees by using an electrostatic field, and simultaneously achieving energy focusing and direction focusing of the ions in the process, thereby significantly improving the resolution of the instrument.

[0036] The ion shaping module optimizes the spatial distribution of the ion beam and improves the resolution of the multiple-reflection time-of-flight mass analyzer.

[0037] The multiple-reflection time-of-flight mass analyzer part of the multiple-reflection time-of-flight mass spectrometer is an electrostatic ion beam trap, which is composed of two groups of symmetrical ion reflection lenses and a pulse drift region in the middle. The conventional reflection type time-of-flight mass spectrometer currently used is reflected once in the reflection region, while the multiple-reflection time-of-flight mass analyzer involved in the present application has two reflection regions at both ends of the flight region. The potential of the reflection regions at both ends is raised after the ion beam enters the flight region, so that the ion cannot pass through the reflection region and can only be reflected back to the flight region. The ion repeatedly moves back and forth in the flight region between the reflection regions at both ends, so that the actual flight distance of the ion is extended.

[0038] Based on the above composition of the multiple-reflection time-of-flight mass spectrometer, the mass resolution of the mass spectrometer can reach 100000 Th / Th, realizing high-precision measurement of Li~U element isotope ratio. At the same time, due to its strong anti-interference ability, the mass spectrometer can perform high-precision detection on complex matrix.

[0039] Further, the vacuum of the three-dimensional femtosecond laser ablation laser resonance ionization multiple-reflection time-of-flight mass spectrometer is realized by the vacuum system of the Raman-LIBS-mass spectrometry combined analysis device, and the data acquisition and processing and control are realized by the control system of the Raman-LIBS-mass spectrometry combined analysis device.

[0040] Further, a femtosecond laser is arranged in the first incident light path system as a first laser source, the wavelength of the femtosecond laser is ≤517 nm, the pulse width is <500 fs, and the repetition frequency is ≥500 kHz.

[0041] The optical path shaping assembly comprises a high-precision attenuator, a beam expander, a beam shaper and a mirror arranged in sequence, and is used for adjusting the laser energy, the beam size and the spatial distribution, wherein the high-precision attenuator can adjust the power of the laser from full power to milliwatt level.

[0042] The three-dimensional scanning focusing device integrates X and Y axis galvanometer and Z axis focusing module, and a beam combining mirror is arranged between the X / Y axis galvanometer and the Z axis focusing module; the two-axis scanning galvanometer (X axis galvanometer and Y axis galvanometer) and the focusing Z axis in the three-dimensional scanning focusing device can directly adopt a three-axis galvanometer system.

[0043] The first incident light path system is provided with an objective lens, and the controlled laser is focused to the sample surface to generate a plasma and a neutral particle cloud.

[0044] Further, the cooperative control of the first incident light path system and the second incident light path system satisfies that the delay time of the femtosecond ablation laser and the resonance ionization laser is less than 1 microsecond, and the synchronization accuracy between the multiple resonance ionization lasers reaches the nanosecond level and is controlled by the control system in real time.

[0045] In the Raman-LIBS-mass spectrometry combined analysis method, the control system controls the delay time between the laser for laser ablation and the laser for laser ionization emitted by the first incident light path system and the second incident light path system. The delay between the laser for laser ablation and the laser for laser ionization is less than 1 microsecond, and in order to realize efficient step-by-step resonance ionization, the time synchronization between the several lasers for laser ionization must reach the nanosecond level, and the specific time can be optimized through experiments. The computer sends instructions to the signal control board, the signal control board sends signals to each laser, and the laser emits the required laser according to the signal.

[0046] Further, the vacuum system comprises a mechanical vacuum pump and a turbo molecular pump.

[0047] The vacuum system is a four-stage gradient vacuum, the first-stage vacuum degree is less than 300 Pa, realized by a mechanical vacuum pump, the second-stage vacuum degree is less than 0.5 Pa, the third-stage vacuum degree is less than 3*10 -3 Pa, and the fourth-stage vacuum degree is less than 2*10 -4 Pa; the second-stage to fourth-stage vacuum is realized by a mechanical vacuum pump and a turbo molecular pump.

[0048] Further, the first-stage vacuum of the vacuum system, namely the vacuum pool, the interface and the ion funnel, adopts a mechanical vacuum pump, a large amount of extracted gas is discharged at this stage, and the vacuum degree is required to be less than 300 Pa; the second-stage vacuum chamber provided with an ion lens has a vacuum degree of less than 0.5 Pa; the third-stage is an ion guiding module and a wave trap filter module, and has a vacuum degree of less than 3*10 -3 Pa; the fourth-stage is a multiple reflection time-of-flight mass analyzer and a detector module, and requires a vacuum degree of less than 2*10 -4 Pa. The second-stage to fourth-stage vacuum is realized by a mechanical vacuum pump and a turbo molecular pump, that is, the mechanical vacuum pump is pre-evacuated, and then the turbo molecular pump is continuously operated to maintain the vacuum.

[0049] Further, the multiple reflection time-of-flight mass spectrometer, LIBS spectrometer and Raman spectrometer can work independently or simultaneously.

[0050] Further, the LIBS spectrometer is a femtosecond multi-pulse laser-induced breakdown enhanced spectrometer, which is synchronized with the multiple reflection time-of-flight mass spectrometer, i.e., when the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer performs mass spectrometry analysis, the LIBS spectral signal can be collected simultaneously to realize complementary analysis of element composition under strong matrix interference.

[0051] Further, the femtosecond multi-pulse laser-induced breakdown enhanced spectrometer comprises a spectral collection module, an optical fiber, a spectral device and a LIBS spectrometer detector, which are used to collect spectral signals and perform analysis.

[0052] The Raman spectrometer comprises a collection optical fiber, a filter, a grating or an interferometer and a Raman spectrometer detector, which are used to collect Raman scattering spectral signals and perform analysis.

[0053] The second technical solution of the present application is a Raman-LIBS-mass spectrometry combined analysis method, which is analyzed by the Raman-LIBS-mass spectrometry combined analysis device as described above, and comprises the following steps:

[0054] S1: the system is switched to the Raman mode, the first incident light path system emits laser to irradiate the sample to be measured, molecular structure imaging is performed by the Raman spectrometer, and multi-dimensional analysis data are formed;

[0055] S2: the system is switched to the mass spectrometer mode in the same region, three-dimensional micro-area femtosecond laser ablation is performed by the first incident light path system;

[0056] S3: the tunable laser of the second incident light path system is triggered synchronously to selectively ionize target elements / isotopes;

[0057] S4: the element / isotope composition is analyzed by the multiple reflection time-of-flight mass spectrometer, and the element distribution is verified by the LIBS spectrometer.

[0058] Further, the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer analysis step is as follows: the femtosecond laser source of the first incident light path system emits laser, after energy attenuation of the light path shaping assembly, beam expansion and shaping, through the two-dimensional galvanometer scanning of the three-dimensional scanning focusing device, the Z-axis and the objective lens are accurately focused, and the selected sample area is three-dimensionally laser ablated into a plasma and neutral particle cloud; the second laser source tunable laser of the second incident light path system is adjusted to the appropriate wavelength laser for laser ionization of the target element to be measured, the laser emitted by the tunable laser passes through the independent light path control unit, then is combined into a light path through the mirror and the beam combiner in the light path combining assembly, and finally the laser is focused on the plasma and neutral particle cloud above the sample through the focusing lens, several lasers resonate ionize the neutral particles into ions, and the ion beam formed after ionization can enter the multiple reflection time-of-flight mass analyzer through the ion transmission system, and finally reaches the ion detector for detection.

[0059] Further, the analysis step of the LIBS spectrometer is as follows: the femtosecond laser source of the first incident light path system emits laser, after energy attenuation of the light path shaping assembly, beam expansion and shaping, through the two-dimensional galvanometer scanning of the three-dimensional scanning focusing device, the Z-axis and the objective lens are accurately focused, and the selected sample area is three-dimensionally laser ablated into a plasma and neutral particle cloud; the second laser source tunable laser of the second incident light path system is adjusted to the appropriate wavelength laser for laser ionization of the target element to be measured, the laser emitted by the tunable laser passes through the independent light path control unit, then is combined into a light path through the mirror and the beam combiner in the light path combining assembly, and finally the laser is focused on the plasma and neutral particle cloud above the sample through the focusing lens, several lasers resonate ionize the neutral particles into ions, and the ion beam formed after ionization can enter the multiple reflection time-of-flight mass analyzer through the ion transmission system, and finally reaches the ion detector for detection.

[0060] If the second incident light path system only uses one second laser source tunable laser to work, the LIBS spectrometer is a double-pulse laser-induced breakdown enhanced spectrometer, and if multiple lasers work, the LIBS spectrometer is a multi-pulse laser-induced breakdown enhanced spectrometer.

[0061] Further, the analysis step of the Raman spectrometer is as follows: first, the high-precision attenuator parameters are set according to the energy value required by the Raman spectrum, to ensure that the final laser energy meets the requirements of the Raman spectrum; during operation, the femtosecond laser source of the first incident light path system emits laser, after energy attenuation of the light path shaping assembly, beam expansion and shaping, through the two-dimensional galvanometer scanning of the three-dimensional scanning focusing device, the Z-axis and the objective lens are accurately focused, and the laser is focused on the selected sample area on the sample surface, the scattered light emitted by the sample is collected and then enters the Raman spectrometer through the optical fiber for analysis.

[0062] (III) Advantages

[0063] Compared with the prior art, the present application has the following advantages:

[0064] (1) The three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer, the femtosecond multi-pulse laser-induced breakdown enhanced spectrometer (LIBS spectrometer) and the Raman spectrometer are integrated in the present application, and the three analysis function modules share the laser source, the optical path system, the high-definition observation system, the vacuum sample bin, the vacuum system and the control system, which combines the in-situ, micro-area and high sampling amount characteristics of three-dimensional laser ablation, the high element selectivity, isotopic selectivity, high ion yield of three-dimensional laser resonance ionization and the high isotopic resolution capability of the multiple reflection time-of-flight mass analyzer, can solve the problem of isobaric interference, not only can realize ultra-trace element, isotopic analysis and isotopic ratio analysis under strong matrix interference, but also can analyze the sample molecular structure and composition analysis and Raman scattering imaging.

[0065] (2) The three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer in the present application uses a laser resonance ionization system as an ion source, the laser covers the neutral particle cloud after laser ablation, and multiple lasers resonate and ionize the neutral particles into ions, which can realize ionization efficiency improved by several orders of magnitude compared with traditional analysis, improve the sensitivity and detection limit of the equipment, can detect ultra-trace elements or isotopes, and the ions generated by laser resonance ionization are in a vacuum state, there is no ion transmission loss, which greatly improves the transmission efficiency and sensitivity, and further reduces the matrix effect by removing the ion plasma ion space interaction.

[0066] (3) The multiple reflection time-of-flight mass spectrometer has ultra-high mass resolution and high sensitivity, the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer in the present application not only greatly improves the efficiency and sample ablation amount of laser ablation, improves the sensitivity and detection limit of the equipment, but also realizes precise in-situ micro-area analysis of the sample, solves the problem of isobaric interference, can realize isotopic analysis of ultra-trace nuclides under strong matrix interference, and can meet the needs of high-precision isotopic mass spectrometry.

[0067] (4) The femtosecond multi-pulse laser-induced breakdown enhanced spectrometer (LIBS spectrometer) in the present application greatly improves the sample ablation amount by using a femtosecond laser, greatly prolongs the plasma lifetime and greatly improves the excitation ability of the plasma, realizes 10 -7 orders of magnitude of LIBS detection limit, and at least improves the LIBS detection sensitivity by 2 orders of magnitude; at the same time, the Raman spectroscopy technology in the present application uses a femtosecond laser, enhances the Raman scattering intensity, and significantly improves the detection sensitivity, breaking through the detection limitation of conventional technology. Attached Figure Description

[0068] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 This is a schematic diagram of the structure of a Raman-LIBS-mass spectrometry coupled analysis device according to the present invention;

[0070] Figure 2 This is a schematic diagram of the principle of the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer in the Raman-LIBS-mass spectrometry analysis device of the present invention;

[0071] Figure 3 This is a schematic diagram of the structure of a three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer in a Raman-LIBS-mass spectrometry analysis device of the present invention;

[0072] Figure 4 This is a schematic diagram of the LIBS spectrometer in the Raman-LIBS-mass spectrometry analysis device of the present invention;

[0073] Figure 5 This is a schematic diagram of the Raman spectrometer in the Raman-LIBS-mass spectrometry analysis device of the present invention.

[0074] In the diagram: 1-Multiple reflection time-of-flight mass spectrometer; 101-Multiple reflection time-of-flight mass analyzer; 102-Detector; 103-Ion funnel; 104-Bent quadrupole; 105-Notch filter; 106-90-degree deflection lens; 107-Ion shaping module; 2-LIBS spectrometer; 3-Raman spectrometer; 4-First incident optical path system; 401-First laser source; 402-Optical path shaping component; 403-Three-dimensional scanning focusing device; 404-Objective lens; 5-Second incident optical path system; 501-Second laser source; 502-Independent optical path control unit; 503-Optical path merging component; 504-Focusing unit; 6-High-definition observation system; 7-Vacuum sample chamber; 8-Vacuum system; 801-Mechanical vacuum pump; 802-Turbomolecular pump. Detailed Implementation

[0075] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0076] Following detailed description together with the accompanying drawings will provide those skilled in the art with further understanding of the application. It will be apparent to those skilled in the art that the application can be practiced without all the specific details given below. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring the application. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the application, are given by way of illustration only and are not by way of limitation of the application. Various substitutions, modifications and changes can be made to the embodiments of the application without departing from the spirit and scope of the application. It is intended that the application encompass all such substitutions, modifications and changes as fall within the scope of the appended claims.

[0077] It is to be understood that the foregoing description is exemplary of the application only and is intended to provide an overview for the understanding of the present application and is not intended to limit the true scope of the application, which is to be limited only by the appended claims. Other aspects of the application will become apparent to those skilled in the art and practices, upon examination of the following

[0078] It is also to be understood that the following description is only illustrative of the application and is not intended to limit the true scope of the application, which is to be limited only by the appended claims. Various modifications of the implementation can be made which will be apparent to those with skill in the art, without departing from the true spirit and scope of the application. It is the intention, therefore, to be limited only as apparent in the appended claims.

[0079] Furthermore, in the following description, numerous specific details are set forth in order to provide a thorough understanding of the examples. However, it will be recognized by one skilled in the art that embodiments can be practiced without some or all of these details.

[0080] The technical solutions provided by the embodiments of the present application are described below with reference to the accompanying drawings.

[0081] Embodiment 1

[0082] Referring to Figures 1 to 5 The present application provides a Raman-LIBS-mass spectrometry combined analysis device, comprising a multiple reflection time-of-flight mass spectrometer 1, a LIBS spectrometer 2, a Raman spectrometer 3 and a shared module.

[0083] The common module includes a first incident light path system 4, a second incident light path system 5, a high-definition observation system 6, a vacuum sample chamber 7, a vacuum system 8 and a control system.

[0084] Please refer to Figure 1 , the multi-reflecting time-of-flight mass spectrometer 1 and the LIBS spectrometer 2 share the first incident light path system 4 and the second incident light path system 5, and the Raman spectrometer 3 takes the first incident light path system 4 as a laser source.

[0085] Please refer to Figure 2 , the multi-reflecting time-of-flight mass spectrometer 1 is set as a three-dimensional femtosecond laser ablation laser resonance ionization multi-reflecting time-of-flight mass spectrometer, which includes an interface, an ion transmission system, a multi-reflecting time-of-flight mass analyzer 101 and a detector 102, and the first incident light path system 4 and the second incident light path system 5 generate an ion source of the three-dimensional femtosecond laser ablation laser resonance ionization multi-reflecting time-of-flight mass spectrometer;

[0086] The ion transmission system includes an ion funnel 103, a curved quadrupole rod 104, a notch filter 105, a 90-degree deflection lens 106 and an ion shaping module 107; the curved quadrupole rod 104 acts as an ion guide while removing neutral particles to realize purification of the ion beam; the notch filter 105 selectively removes target ions of a specific mass-to-charge ratio (m / z) from an ion beam containing multiple ions, and the 90-degree deflection lens 106 uses an electrostatic field to accurately deflect the ion beam by 90 degrees, while realizing energy focusing and direction focusing of the ions in the process, thereby improving the resolution of the instrument.

[0087] The LIBS spectrometer 2 is set as a femtosecond multi-pulse laser-induced breakdown enhanced spectrometer, which includes a spectrum collection module, an optical fiber, a light splitting device and a LIBS spectrometer detector, for collecting spectrum signals and performing analysis.

[0088] The Raman spectrometer 3 includes a collection optical fiber, a filter, a grating or an interferometer and a Raman spectrometer detector, for collecting Raman scattering spectrum signals and performing analysis.

[0089] Please refer to Figure 1 , the first incident light path system 4 includes a first laser source 401, a light path shaping assembly 402 and a three-dimensional scanning focusing device 403 arranged in sequence, for generating a femtosecond laser beam and performing three-dimensional ablation on a sample;

[0090] The first incident light path system 4 is provided with a femtosecond laser as the first laser source 401, the wavelength of the femtosecond laser is ≤517 nm, the pulse width is <500 fs, and the repetition frequency is ≥500 kHz; the light path shaping assembly 402 includes a high-precision attenuator, a beam expander, a beam shaper and a mirror arranged in sequence, for adjusting the laser energy, the beam size and the spatial distribution, wherein the high-precision attenuator can adjust the power of the laser from full power to milliwatt level; the three-dimensional scanning focusing device 403 integrates X, Y axis galvanometer and Z axis focusing module, and a beam combining mirror is arranged between the X / Y axis galvanometer and the Z axis focusing module; the two-axis scanning galvanometer (X axis galvanometer, Y axis galvanometer) and the focusing Z axis in the three-dimensional scanning focusing device 403 can directly use a three-axis galvanometer system; the first incident light path system 4 is provided with an objective lens 404 at the terminal, and the regulated laser is focused to the surface of the sample to generate a plasma and a neutral particle cloud.

[0091] Please refer to Figure 1 again, the second incident light path system 5 includes a second laser source 501, an independent light path regulation unit 502, a light path combining assembly 503 and a focusing unit 504 arranged in sequence, for combining the tunable lasers into a resonance ionization light path; the lasers of the plurality of second laser sources 501 pass through the respective independent light path regulation units 502, and then are combined into a second single light path through the light path combining assembly 503, and the second single light path enters the vacuum sample chamber 7 through the focusing unit 504.

[0092] Please refer to Figure 1 again, the three second laser sources 501 are tunable lasers, and the wavelength tuning range of the tunable lasers is 210 nm~4500 nm; the three independent light path regulation units 502 are arranged on the light paths of the three second laser sources 501, and include an attenuator and a beam expander arranged in sequence; the light path combining assembly 503 includes a mirror and a beam combining mirror, and combines multiple lasers into a single light path; the focusing unit 504 includes a window piece and a focusing lens, and focuses the combined laser to the sample ablation area; according to the target element to be measured, the trigger of the three second laser sources 501 and the wavelength of the respective output laser are controlled by the control system.

[0093] The cooperative control of the first incident light path system 4 and the second incident light path system 5 satisfies that the delay time of the femtosecond ablation laser and the resonance ionization laser is <1 μs; the synchronization accuracy among the multiple resonance ionization lasers reaches nanosecond level, which is real-time regulated by the control system, specifically: the computer sends instructions to the signal control board, the signal control board sends signals to each laser, and the laser emits the required laser according to the signal.

[0094] Please refer to Figure 1The high-definition observation system 6 is a coaxial observation system, mainly composed of a camera, a lens barrel, a beam combiner and an objective lens, wherein the objective lens is shared with the first incident light path system 4, that is, the objective lens 404, and the high-definition observation system 6 is used for observing the sample position, the sample state and the condition in the vacuum pool during sample analysis.

[0095] Please refer to Figure 1 The vacuum sample chamber 7 comprises a three-axis nanometer moving stage, a sample support and a temperature control station, and is fully sealed; the three-axis nanometer moving stage is installed on the base of the vacuum sample chamber 7, is a three-axis nanometer vacuum moving stage, has a resolution less than or equal to 10 nm and a repeat positioning accuracy less than or equal to 300 nm; the temperature control station is used for accurately controlling the temperature of the sample, and has a control temperature accuracy of 0.1 degrees Celsius; and the sample support is used for placing and fixing the sample.

[0096] The control system mainly comprises a computing workstation, communication modules of various components, various sensors, a vacuum gauge, a signal control board and the like, and is used for collecting, processing and sending information data to control the cooperative work of various components.

[0097] Please refer to Figure 1 The vacuum system 8 comprises a mechanical vacuum pump 801 and a turbo molecular pump 802, and is a four-stage gradient vacuum system.

[0098] The first-stage vacuum of the vacuum system 8, that is, the vacuum pool, the interface and the ion funnel 103, adopts the mechanical vacuum pump 801, a large amount of extracted gas is discharged at this stage, and the required vacuum degree is less than 300 Pa; the second-stage vacuum chamber provided with an ion lens has a vacuum degree less than 0.5 Pa; the third-stage is an ion guide and a trap filter 105 module, and has a vacuum degree less than 3*10 -3 Pa; and the fourth-stage is a multiple reflection time-of-flight mass analyzer 101 and a detector 102 module, and requires a vacuum degree less than 2*10 -4 Pa. The second-stage to fourth-stage vacuum adopts the mechanical vacuum pump 801 and the turbo molecular pump 802 to realize together, that is, the mechanical vacuum pump 801 is used for pre-extraction of vacuum, and then the turbo molecular pump 802 is continuously operated to maintain the vacuum.

[0099] The multiple reflection time-of-flight mass spectrometer 1, the LIBS spectrometer 2 and the Raman spectrometer 3 can work independently or simultaneously; when working simultaneously, that is, the three-dimensional femtosecond laser ablation laser resonance ionization multiple reflection time-of-flight mass spectrometer can collect the LIBS spectral signal simultaneously during mass spectrum analysis, so as to realize complementary analysis of element composition under strong matrix interference.

[0100] Please refer to Figure 1 The application further provides a Raman-LIBS-mass spectrometry combined analysis method, which is analyzed by the Raman-LIBS-mass spectrometry combined analysis device as described above and comprises the following steps.

[0101] S1: The system switches to the Raman mode, the first incident light path system 4 emits laser light to irradiate the sample to be measured, and the molecular structure is imaged by the Raman spectrometer 3 to form multi-dimensional analysis data;

[0102] S2: The system in the same region switches to the mass spectrometer mode, and three-dimensional micro-area femtosecond laser ablation is performed by the first incident light path system 4;

[0103] S3: The tunable laser of the second incident light path system 5 is triggered synchronously to selectively ionize the target element / isotope;

[0104] S4: The element / isotope composition is analyzed by the multi-reflection time-of-flight mass spectrometer 1, and the element distribution is verified by the LIBS spectrometer 2.

[0105] A zircon sample (TEMORA-1) was subjected to U-Pb dating analysis. The first incident light path system 4 used femtosecond laser (pulse width 250 fs, spot 2 μm) to ablate the sample; the second incident light path system 5 used three tunable lasers (λ1=283.3 nm, λ2=600.2 nm, λ3=1064 nm) to ionize lead atoms step by step. The trap filter 105 was set to m / z=207.2±0.3 Th to filter out 207 Pb + interference. The measured 206 Pb / 238 U=0.067±0.003(2σ), with an accuracy better than single laser ablation ICP-MS (±0.02 vs ±0.05).

[0106] In the present specification, the same or similar parts among various embodiments can be mutually referred to, and each embodiment focuses on the difference from other embodiments.

[0107] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in the present application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A Raman-LIBS-mass spectrometry combined analysis device, characterized in that, The system comprises a multi-reflection time-of-flight mass spectrometer (1), a LIBS spectrometer (2), a Raman spectrometer (3) and a shared module; The shared module comprises a first incident light path system (4), a second incident light path system (5), a high-definition observation system (6), a vacuum sample chamber (7), a vacuum system (8) and a control system; The first incident light path system (4) comprises a first laser source (401), a light path shaping assembly (402) and a three-dimensional scanning focusing device (403) arranged in sequence, and is used for generating a femtosecond laser beam and performing three-dimensional ablation on a sample; The second incident light path system (5) comprises a second laser source (501), an independent light path control unit (502), a light path merging assembly (503) and a focusing unit (504) arranged in sequence, and is used for merging tunable lasers into a resonance ionization light path; The second incident light path system (5) is provided with a plurality of second laser sources (501), the second laser sources (501) are arranged as tunable lasers, the wavelength tuning range of the tunable lasers is 210 nm-4500 nm, the independent light path control unit (502) corresponds to the second laser source (501) in one-to-one correspondence, and comprises an attenuator and a beam expander arranged in sequence; the light path merging assembly (503) comprises a mirror and a beam combiner, and is used for merging a plurality of laser beams into a single light path; the focusing unit (504) comprises a window sheet and a focusing lens, and is used for focusing the merged laser beam to a sample ablation area; The laser beams of the plurality of second laser sources (501) pass through the independent light path control unit (502), are merged into a second single light path by the light path merging assembly (503), and enter the vacuum sample chamber (7) through the focusing unit (504); The multi-reflection time-of-flight mass spectrometer (1) and the LIBS spectrometer (2) share the first incident light path system (4) and the second incident light path system (5), and the Raman spectrometer (3) takes the first incident light path system (4) as a laser source; The multi-reflection time-of-flight mass spectrometer (1) is arranged as a three-dimensional femtosecond laser ablation laser resonance ionization multi-reflection time-of-flight mass spectrometer, the first incident light path system (4) and the second incident light path system (5) generate an ion source of the three-dimensional femtosecond laser ablation laser resonance ionization multi-reflection time-of-flight mass spectrometer; The cooperative control of the first incident light path system (4) and the second incident light path system (5) satisfies that the delay time of the femtosecond ablation laser and the resonance ionization laser is less than 1 μs, and the synchronization accuracy between the multiple resonance ionization lasers reaches the nanosecond level, which is controlled in real time by the control system.

2. The Raman-LIBS-mass spectrometry combined analysis device according to claim 1, characterized in that, The working number of the second laser source (501) can be dynamically adjusted by the control system, and is selectively combined and triggered according to the ionization demand of a target element.

3. The Raman-LIBS-mass spectrometry combined analysis device according to claim 1, characterized in that, The three-dimensional femtosecond laser ablation laser resonance ionization multi-reflection time-of-flight mass spectrometer comprises an interface, an ion transmission system, a multi-reflection time-of-flight mass analyzer (101) and a detector (102); The ion transmission system comprises an ion funnel (103), a curved quadrupole rod (104), a notch filter (105), a 90-degree deflection lens (106) and an ion shaping module (107).

4. The Raman-LIBS-mass spectrometry combined analysis device according to claim 1, characterized in that, The first incident light path system (4) is provided with a femtosecond laser as a first laser source (401), the wavelength of the femtosecond laser is ≤517 nm, the pulse width is <500 fs, and the repetition frequency is ≥500 kHz; The light path shaping assembly (402) comprises a high-precision attenuator, a beam expander, a beam shaper and a reflector arranged in sequence, and is used for adjusting the laser energy, the beam size and the spatial distribution; The three-dimensional scanning focusing device (403) is integrated with an X-Y axis galvanometer and a Z-axis focusing module, and a beam combiner is arranged between the X-Y axis galvanometer and the Z-axis focusing module; The first incident light path system (4) is provided with an objective lens (404) at the terminal, which focuses the regulated laser to the surface of the sample to generate a plasma and a neutral particle cloud.

5. The Raman-LIBS-mass spectrometry combined analysis device according to claim 1, characterized in that, The vacuum system (8) comprises a mechanical vacuum pump (801) and a turbo molecular pump (802); The vacuum system (8) is a four-stage gradient vacuum, the first-stage vacuum degree is <300 Pa, realized by a mechanical vacuum pump (801), the second-stage vacuum degree is <0.5 Pa, the third-stage vacuum degree is <3*10 -3 Pa, and the fourth-stage vacuum degree is <2*10 -4 Pa; the second-stage to fourth-stage vacuum is realized by a mechanical vacuum pump (801) and a turbo molecular pump (802) together.

6. The Raman-LIBS-mass spectrometry combined analysis device according to claim 1, characterized in that, The multi-reflecting time-of-flight mass spectrometer (1), the LIBS spectrometer (2) and the Raman spectrometer (3) can work independently or simultaneously.

7. The Raman-LIBS-mass spectrometry combined analysis device according to claim 6, characterized in that, The LIBS spectrometer (2) is a femtosecond multi-pulse laser-induced breakdown enhanced spectrometer, and the LIBS spectrometer (2) works synchronously when the multi-reflecting time-of-flight mass spectrometer (1) analyzes, that is, when the three-dimensional femtosecond laser ablation laser resonance ionization multi-reflecting time-of-flight mass spectrometer performs mass spectrum analysis, the LIBS spectrum signal can be collected simultaneously, and the complementary analysis of the element composition under strong matrix interference is realized.

8. A Raman-LIBS-mass spectrometry combined analysis method, wherein the Raman-LIBS-mass spectrometry combined analysis method is analyzed by the Raman-LIBS-mass spectrometry combined analysis device according to claim 1. The method comprises the following steps: S1: the system is switched to the Raman mode, the first incident light path system (4) emits laser to irradiate the sample to be measured, the molecular structure imaging is performed through the Raman spectrometer (3), and multi-dimensional analysis data are formed; S2: the system is switched to the mass spectrometer mode in the same region, the three-dimensional micro-area femtosecond laser ablation is performed through the first incident light path system (4); S3: the tunable laser of the second incident light path system (5) is triggered synchronously, and the target element / isotope is selectively ionized; S4: the element / isotope composition is analyzed through the multi-reflecting time-of-flight mass spectrometer (1), and the element distribution is verified in combination with the LIBS spectrometer (2).

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