Parallel multi-dimensional gas chromatography connecting device

Abstract

The invention discloses a parallel multi-dimensional gas chromatography connecting device, and belongs to the technical field of analytical instruments. The parallel multi-dimensional gas chromatography connecting device comprises a partial pressure valve, a parallel multi-dimensional chromatography passage, a passage valve and a signal interaction system which are mounted in a shell, the passage valve can switch the multi-dimensional chromatography passage, and the partial pressure valve can adjust the partial pressure entering each passage. The parallel multi-dimensional chromatographic passage comprises a chromatographic column fixing mechanism and a chromatographic column, and an inlet and an outlet of the parallel multi-dimensional chromatographic passage are respectively connected with the partial pressure valve and the passage valve. A special access valve is used for access selection control, and chromatographic columns with different parameters are connected in parallel. And each chromatographic column is independent and scans at the same frequency, so that the real multi-dimensional gas chromatography detection is realized, and the qualification is clear at a glance. The compound judgment basis can be increased, the resolution ratio, the error-tolerant rate and the selectivity are high, and the application range is wide. The connecting device does not need a special modulator-demodulator, the problems that the modulator-demodulator is harsh in application condition and high in operation and maintenance cost are solved, and the detection cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical instruments, and in particular relates to a parallel multi-dimensional gas chromatography connection device. Background Art

[0002] Gas chromatography is mainly based on the molecular weight and polarity of gaseous compound molecules, using the difference in their retention time on the chromatographic column to achieve separation between different compounds. It is widely used in separation and detection in scientific research and production in the fields of petroleum, chemical industry, environmental protection, medicine, food, biochemistry, etc. It is one of the fastest-growing, most widely used and most promising technical fields in modern analytical instruments. In practical applications, there are many complex samples. Using conventional chromatographic analysis methods with a single chromatographic column and a single detector combination, it is difficult to obtain satisfactory analysis results by simply improving column efficiency or selectivity. Multidimensional chromatography can solve the problem of quantitative determination of a large number of complex samples and trace components.

[0003] Multidimensional gas chromatography switching technology uses two or more chromatographic columns or two or more detectors to measure and analyze gases, so that multiple chromatographic or signal information can be obtained simultaneously in one injection, which is conducive to the identification of difficult-to-separate components. The existing multidimensional gas chromatography mainly has two modes: two-dimensional gas chromatography (GC+GC) and full two-dimensional gas chromatography (GC×GC). Two-dimensional gas chromatography (GC+GC): also called center cutting, refers to a window in a one-dimensional chromatogram switched to the second chromatographic column for secondary separation, that is, only a part of the compounds of interest have undergone two different chromatographic column separations. Each injection transfers a section or several sections of the one-dimensional column to the two-dimensional column, and most of the components of the pre-column are vented through the limiting flow tube, resulting in sample waste. If multiple injections are required for the full analysis of the mixture, it will take a long time. It is difficult to achieve ideal separation and analysis effects for components with large content differences, many isomers, and severe mutual interference.

[0004] Comprehensive two-dimensional gas chromatography (GC×GC) is to connect two chromatographic columns with different separation mechanisms and independent of each other in series into a two-dimensional gas chromatography using a modulator. The two chromatographic columns are connected in series through a modem. All compounds have undergone two different chromatographic column separations. Compared with traditional one-dimensional chromatography, the separation ability has been greatly improved, with the advantages of high sensitivity, high peak capacity, and the ability to achieve family separation. The existing comprehensive two-dimensional gas chromatography technology with two chromatographic columns in series is not truly two-dimensional. The signal of the detector is flipped to the Y axis for display in each scanning cycle (such as 3 to 6 seconds), so the X axis records a signal once per cycle (3 to 6 seconds), and the total time of the Y cycle is a complete cycle (3 to 6 seconds), with low resolution and poor selectivity for isomers. At the same time, affected by the series connection of chromatographic columns, the separation speed of the chromatographic columns needs to be improved. In addition, the compounds separated by the one-dimensional column are collected and injected into the two-dimensional column in a pulsed manner by using a modem through sudden cooling and heating. Ice blockage is very likely to occur during liquid nitrogen sudden cooling, and the maintenance cost of liquid nitrogen and the demodulator is high.

[0005] In view of the problems of existing comprehensive two-dimensional gas chromatography (GC×GC), such as the need to improve the resolution and chromatographic column separation speed, harsh application conditions of the modulator and high cost, a parallel multidimensional gas chromatography connection device is urgently needed to be developed, which can increase the basis for compound identification, have high resolution, fault tolerance and selectivity, a wide range of applications, and reduce operating and maintenance costs. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the background technology and to provide a parallel multidimensional gas chromatography connection device which can increase the basis for compound determination, has high resolution, fault tolerance and selectivity, has a wide range of applications, and can reduce operating and maintenance costs.

[0007] To achieve the above object, the present invention provides the following technical solutions: A parallel multidimensional gas chromatography connection device comprises a shell, a pressure dividing valve, a parallel multidimensional chromatographic passage, a passage valve and a signal interaction system, wherein the pressure dividing valve, the parallel multidimensional chromatographic passage, the passage valve and the signal interaction system are fixedly installed inside the shell; the passage valve is a multi-passage valve that can switch the fluid path, and can switch the parallel multidimensional chromatographic passage; the parallel multidimensional chromatographic passage comprises a chromatographic column fixing mechanism and a chromatographic column; the injection port of the pressure dividing valve is connected to the injector, and the pressure dividing valve outlet is respectively connected to the multidimensional chromatographic passage to connect chromatographic columns of different parameters in parallel, and adjust the pressure difference entering each passage; the outlet of the parallel multidimensional chromatographic passage is connected to a detector through the passage valve; the signal interaction system electrically connects the passage valve and the detector through a control circuit.

[0008] Preferably, the chromatographic column fixing mechanism is a structure such as a hook, a clamping ring, a cable tie, a retention groove, etc. fixed in the shell to facilitate the replacement and fixing of the chromatographic column.

[0009] The second object of the present invention is to provide a special passage valve for a parallel multi-dimensional gas chromatography connection device: the passage valve includes a mounting shell, a movable block is installed through the top of the mounting shell, an air outlet pipe is installed through the surface of the movable block, and a plurality of air inlet pipes are installed through the side of the mounting shell, one end of the air outlet pipe and the plurality of air inlet pipes extend to the interior of the mounting shell, a second trumpet-shaped interface is movably installed at one end of the air outlet pipe, and a first trumpet-shaped interface is fixedly installed at one end of the plurality of air inlet pipes, and the second trumpet-shaped interface is in close contact with the first trumpet-shaped interface.

[0010] Preferably, a gear ring is fixedly mounted on the top of the movable block, a gear is meshed on one side of the gear ring, a driving motor is connected to the surface of the gear, and a housing of the driving motor is mounted on the top of the mounting housing through a motor bracket.

[0011] Preferably, a slide groove is provided along the arc side surface of the movable block, a plurality of universal ball bearings arranged at equal angles are provided inside the slide groove, and a fixed housing of the universal ball bearings is installed on the top of the mounting housing.

[0012] Preferably: one end of the air outlet pipe is connected to a movable pipe fitting via a piston sealing ring, one end of the movable pipe fitting is connected to a second trumpet-shaped interface, the surface fixed sleeve of the air outlet pipe is provided with a fixed ring, the surface movable sleeve of the movable pipe fitting is provided with a compression spring, and both ends of the compression spring are respectively installed on the surface of the fixed ring and the second trumpet-shaped interface.

[0013] Preferably: two symmetrically arranged mounting rods are installed through the side of the fixing ring, one end of the mounting rod is installed on the side of the second trumpet-shaped interface, and an iron block is installed on the other end of the mounting rod, and an electromagnet with a corresponding position is provided on one side of the iron block, and a fixing part is connected between the electromagnet and the fixing ring.

[0014] Preferably, an infrared transmitter is installed at the bottom of the air outlet pipe, and a plurality of infrared receivers are installed on the inner bottom surface of the installation shell, and the positions of the infrared receivers and the air inlet pipe correspond.

[0015] Preferably: a baffle is provided inside one end of the first trumpet-shaped interface, a second rubber sealing gasket is bonded to the arc surface of the baffle, the second rubber sealing gasket is in contact with the inner surface of the first trumpet-shaped interface, fixing rods are installed on the top and bottom of the baffle, fixing blocks are installed at one end of the two fixing rods, torsion springs are provided on the surface movable sleeves of the two fixing rods, the two ends of the torsion springs are respectively installed on the surface of the fixing block and the first trumpet-shaped interface, a connecting rod is installed inside the second trumpet-shaped interface, and a push rod corresponding to the position of the baffle is installed on the side of the connecting rod.

[0016] Another object of the present invention is to provide a signal separation method of a parallel multidimensional gas chromatograph using the parallel multidimensional gas chromatograph connection device of the present invention, comprising the following steps: S1: The sample to be tested is sent into the gas chromatography system by an automatic sample injector. The target compound is separated in multiple stages on the parallel multidimensional gas chromatography and reaches the detector (such as FID or mass spectrometer, etc.) respectively to obtain the coordinate data of the chromatogram (non-mass spectrometer, such as FID, FPD, ECD, etc.) or the total ion current map (mass spectrometer).

[0017] S2: According to the scanning frequency of the detector (the same as the switching frequency of the passage valve), the coordinate data obtained in step S1 is split into three groups of coordinate data, corresponding to the three passages respectively.

[0018] S3: Based on the three sets of coordinate data obtained in S2, three spectra are regenerated with retention time as the horizontal axis (X-axis) and electrical signal (or ion abundance) as the vertical axis (Y-axis).

[0019] S4: Based on the three sets of coordinate data obtained in S2, the three coordinates (x, y, z) of the target compound are found, corresponding to their retention times on the three chromatographic columns, and a three-dimensional scatter distribution diagram is drawn to achieve simple and intuitive visualization of the determination of the target compound.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. The parallel multidimensional gas chromatography connection device of the present invention connects chromatographic columns with different parameters in parallel, and each chromatographic column scans independently and at the same frequency, thereby realizing multidimensional gas chromatography detection in a true sense, with high resolution, clear qualitative analysis, increased basis for compound determination, and high selectivity (such as isomers cannot be distinguished in mass spectrometry), which can increase the basis for compound determination and has a wide range of applications.

[0021] 2. The parallel multi-dimensional gas chromatograph connection device of the present invention does not require a special modem for parallel connection of chromatographic columns, thus overcoming the problems of harsh application conditions and high operation and maintenance costs of modems and reducing detection costs.

[0022] 3. The passage valve of the present invention is connected by the second trumpet-shaped interface and the first trumpet-shaped interface. According to the principle of fluid dynamics, the gas first flows in the first trumpet-shaped interface along the gradually expanding inner cavity, and then flows into the second trumpet-shaped interface along the gradually shrinking inner cavity, so that the gas can flow smoothly from the air inlet pipe to the air outlet pipe, overcoming the problem of gas discontinuity when the two pipelines are hard-connected, optimizing the gas delivery state, allowing the gas to be delivered continuously, and improving the efficiency and stability of gas delivery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of the parallel multi-dimensional gas chromatography connection device of the present invention connected to a gas chromatograph; Figure 2 It is a structural schematic diagram of the passage valve of the present invention; Figure 3 is a cross-sectional view of a passage valve of the present invention; Figure 4 It is a schematic diagram of the connection structure of the first trumpet-shaped interface and the second trumpet-shaped interface of the present invention; Figure 5 It is a schematic diagram of the connection structure between the air outlet pipe and the second trumpet-shaped interface of the present invention; Figure 6 It is a schematic diagram of the connection structure between the air intake pipe and the first trumpet-shaped interface of the present invention; Figure 7 It is a schematic diagram of the connection structure of the baffle and the fixing rod of the present invention; Figure 8 is the total ion current of the signal of Example 2 of the present invention (methyl oleate 200 ppb); Fig. 9 This is the total ion current diagram reproduced after the coordinate points are split according to Example 2 of the present invention (methyl oleate 200 ppb); Fig.10 The chromatogram (20 ppm) of conjugated linoleic acid methyl ester (CLA n6 and CLA n7) of Example 3 of the present invention; Fig.11 This is the chromatogram (20 ppm) after separation and reset of conjugated linoleic acid methyl ester (CLA n6 and CLA n7) in Example 3 of the present invention; Fig.12 The total ion current diagram of the fatty acid methyl ester mixed standard (0.2-10 ppm) of Example 4 of the present invention; Fig.13 The chromatogram (0.2-10 ppm) after the fatty acid methyl ester mixed standard separation and reset in Example 4 of the present invention; Fig.14 This is a three-dimensional coordinate distribution diagram of the retention time of Example 4 of the present invention.

[0024] In the figure: universal ball 1, mounting shell 2, gear ring 3, air outlet pipe 4, drive motor 5, air inlet pipe 6, pressure dividing valve 7, gear 8, slide 9, movable block 10, first trumpet-shaped interface 11, signal interaction system 12, second trumpet-shaped interface 13, fixing ring 14, mounting rod 15, electromagnet 16, infrared receiver 17, limit ring 18, fixing part 19, passage valve 20, parallel multi-dimensional chromatographic passage 21, compression spring 22, first rubber sealing gasket 23, infrared transmitter 24, iron block 25, movable pipe 26, torsion spring 27, fixing block 28, fixing rod 29, second rubber sealing gasket 30, baffle 31, shell 32, push rod 33, connecting rod 34, injector 35, detector 36. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, a detailed description is given below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1 Multidimensional Gas Chromatography Linking Device like Figure 1 As shown, a parallel multidimensional gas chromatography connection device includes a shell 32, a pressure dividing valve 7, a parallel multidimensional chromatography passage 21, a passage valve 20 and a signal interaction system 12, wherein the pressure dividing valve 7, the parallel multidimensional chromatography passage 21, the passage valve 20 and the signal interaction system 12 are fixedly installed inside the shell 32; the passage valve 20 is a multi-pass valve that can switch the fluid path, and can switch the parallel multidimensional chromatography passage; the parallel multidimensional chromatography passage 21 includes a chromatographic column fixing mechanism and a chromatographic column; the injection port of the pressure dividing valve 7 is connected to the injector 35, and the sample outlet of the pressure dividing valve 7 connects three chromatographic columns with different parameters in parallel through the parallel multidimensional chromatography passage 21, and adjusts the partial pressure entering each passage; the outlet of the parallel multidimensional chromatography passage 21 is connected to the detector 36 through the passage valve 20; the signal interaction system electrically connects the passage valve 20 and the detector 36 through a control circuit. The injector 35 allows compounds to enter and pass through the vaporization chamber 250-300°C therein to complete instantaneous vaporization, and the compound gas molecules enter the chromatographic separation stage with the carrier gas; the vaporized compounds are transported to three chromatographic columns with different parameters through the pressure divider valve 7 for chromatographic separation, and the chromatographic columns with large polarity differences are selected for combination, which essentially realizes the differentiation of chromatographic separation. The compound molecules coming from the pressure divider valve 7 have different retention times in the three chromatographic columns, and the target compound obtains three different retention times. Two compounds may have the same retention time on the same chromatographic column, and are less likely to have the same retention time on the second chromatographic column, and are extremely likely to be the same on all three chromatographic columns. Two compounds can be accurately detected through the chromatographic columns; the detector 36 separates the signals of each path to form three independent chromatograms. Common universal detectors for gas chromatography include FID, ECD, FPD, etc., and a mass spectrometer detector can also be used.

[0027] like Figures 2 to 7 It is shown that another object of the present invention is to provide a special access valve for a parallel multi-dimensional gas chromatography connection device: the access valve 20 includes a mounting shell 2, a movable block 10 is installed through the top of the mounting shell 2, an air outlet pipe 4 is installed through the surface of the movable block 10, and a plurality of air inlet pipes 6 are installed through the side of the mounting shell 2, and one end of the air outlet pipe 4 and the plurality of air inlet pipes 6 extend to the interior of the mounting shell 2, a second trumpet-shaped interface 13 is movably installed at one end of the air outlet pipe 4, a first trumpet-shaped interface 11 is fixedly installed at one end of the plurality of air inlet pipes 6, and the second trumpet-shaped interface 13 is in close contact with the first trumpet-shaped interface 11, and the plurality of air inlet pipes 6 are respectively connected to the outlets of three chromatographic columns with large polarity differences through pipes. At this time, the number of air inlet pipes 6 is three, which is the same as the number of chromatographic columns. In the process of sequentially transporting the gases in the three chromatographic columns to the detector 36, The air outlet pipe 4 needs to be rotated and rotated to the air inlet pipe 6 connected to the chromatographic column at the corresponding position. During operation, it is only necessary to rotate the air outlet pipe 4. After the air outlet pipe 4 is subjected to force, it drives the movable block 10 to rotate on the mounting shell 2. After the air outlet pipe 4 rotates to a certain angle, the air outlet pipe 4 drives the second trumpet-shaped interface 13 to correspond to the position of the first trumpet-shaped interface 11 on the air inlet pipe 6, so that the connection between the air inlet pipe 6 and the air outlet pipe 4 can be completed. Through the docking method of the trumpet-shaped interfaces and the principle of fluid dynamics, the gas first flows in the first trumpet-shaped interface 11 along the gradually expanding inner cavity, and then flows into the second trumpet-shaped interface 13 and flows along the gradually shrinking inner cavity, so that the gas can flow smoothly from the air inlet pipe 6 to the air outlet pipe 4, overcoming the problem of gas discontinuity when the two pipelines are hard-docked, optimizing the gas delivery state, and enabling the gas to be continuously delivered.

[0028] A gear ring 3 is fixedly installed on the top of the movable block 10, and a gear 8 is meshed on one side of the gear ring 3. A drive motor 5 is connected to the surface of the gear 8. The housing of the drive motor 5 is installed on the top of the installation housing 2 through a motor bracket. The drive motor 5 works after being energized. The drive motor 5 drives the gear 8 to rotate, and the gear 8 controls the rotation of the gear ring 3. The gear ring 3 drives the movable block 10 to rotate in the installation housing 2, which facilitates the rotation of the air outlet pipe 4 in the installation housing 2.

[0029] A slide groove 9 is opened along the arc side of the movable block 10, and a plurality of universal ball bearings 1 arranged at equal angles are arranged inside the slide groove 9. The fixed shell of the universal ball bearings 1 is installed on the top of the mounting shell 2. When the movable block 10 rotates, the slide groove 9 of the movable block 10 rotates on the plurality of universal ball bearings 1, which reduces the friction force when the movable block 10 rotates and improves the rotation stability of the movable block 10 in the mounting shell 2.

[0030] One end of the air outlet pipe 4 is connected to a movable pipe fitting 26 through a piston sealing ring, and one end of the movable pipe fitting 26 is connected to a second trumpet-shaped interface 13. A fixed ring 14 is fixedly sleeved on the surface of the air outlet pipe 4, and a compression spring 22 is movablely sleeved on the surface of the movable pipe fitting 26. Both ends of the compression spring 22 are respectively installed on the surfaces of the fixed ring 14 and the second trumpet-shaped interface 13. As the air outlet pipe 4 rotates, the second trumpet-shaped interface 13 is first separated from the first trumpet-shaped interface 11. During the separation process, the second trumpet-shaped interface 13 pushes the movable pipe fitting 26 to slide in the air outlet pipe 4, and at the same time, the second trumpet-shaped interface 13 pushes the compression spring 22, so that the compression spring 22 is in a compressed state after being subjected to force, thereby facilitating the rotation operation of the air outlet pipe 4.

[0031] Two symmetrically arranged mounting rods 15 are installed through the side of the fixing ring 14, one end of the mounting rod 15 is installed on the side of the second trumpet-shaped interface 13, and an iron block 25 is installed on the other end of the mounting rod 15. An electromagnet 16 with a corresponding position is provided on one side of the iron block 25, and a fixing part 19 is connected between the electromagnet 16 and the fixing ring 14. When operating the second trumpet-shaped interface 13 to separate from the first trumpet-shaped interface 11, the two electromagnets 16 are energized to work first, and the two electromagnets 16 generate magnetic force after being energized. The two electromagnets 16 attract the iron blocks 25 through the magnetic force, and the two iron blocks 25 move toward the electromagnets 16 after being subjected to force. Therefore, the two iron blocks 25 pull the two mounting rods 15 to drive the second trumpet-shaped interface 13 to separate from the first trumpet-shaped interface 11, which is used to complete the preparation work before the rotation of the air outlet pipe 4.

[0032] An infrared transmitter 24 is installed at the bottom of the air outlet pipe 4, and a plurality of infrared receivers 17 are installed on the inner bottom surface of the mounting shell 2. The positions of the infrared receivers 17 and the air inlet pipe 6 correspond. As the air outlet pipe 4 rotates from one air inlet pipe 6 to another air inlet pipe 6, the infrared transmitter 24 on the air outlet pipe 4 moves from one infrared receiver 17 to above another infrared receiver 17. After the infrared transmitter 24 and the infrared receiver 17 are connected, the infrared receiver 17 feeds back a signal to the PLC controller. The PLC controller controls the drive motor 5 to stop working, so as to assist the air outlet pipe 4 to rotate and contact the corresponding position of the air inlet pipe 6.

[0033] A baffle 31 is provided inside one end of the first trumpet-shaped interface 11, and a second rubber sealing gasket 30 is bonded to the arc surface of the baffle 31. The second rubber sealing gasket 30 contacts the inner surface of the first trumpet-shaped interface 11, and fixing rods 29 are installed on the top and bottom of the baffle 31. A fixing block 28 is installed at one end of the two fixing rods 29. A torsion spring 27 is movably sleeved on the surface of the two fixing rods 29. The two ends of the torsion spring 27 are respectively installed on the surface of the fixing block 28 and the first trumpet-shaped interface 11. A connecting rod 34 is installed inside the second trumpet-shaped interface 13, and a push rod 33 corresponding to the position of the baffle 31 is installed on the side of the connecting rod 34. The cooperation between the baffle 31 and the second rubber sealing gasket 30 is used to seal the outlet of the air inlet pipe 6. If the gas in the chromatographic column at another position leaks into the mounting housing 2 due to operational errors, and the positions of the first trumpet-shaped interface 11 and the second trumpet-shaped interface 13 correspond, after the electromagnet 16 is powered off, the compressed state The compression spring 22 pushes the second trumpet-shaped interface 13 toward the first trumpet-shaped interface 11 in the reverse direction through its own elastic potential energy, and the second trumpet-shaped interface 13 drives the push rod 33 to push the baffle 31 through the connecting rod 34. After the baffle 31 is subjected to the force, it drives the fixing rod 29 to rotate in the first trumpet-shaped interface 11, and at the same time, the fixing rod 29 applies a torque force to the torsion spring 27. At this time, the torsion spring 27 is in an energy storage state, and a gap is generated between the baffle 31 and the first trumpet-shaped interface 11, which facilitates the gas to flow into the outlet pipe 4 from the space between the baffle 31 and the first trumpet-shaped interface 11, thereby facilitating the gas to be transported to the detector 36. In the process of separation of the first trumpet-shaped interface 11 from the second trumpet-shaped interface 13, the torsion spring 27 drives the baffle 31 to rotate in the reverse direction through its own elastic potential energy, so that the baffle 31 and the second rubber sealing gasket 30 are reset, so that the baffle 31 can seal the interface of the first trumpet-shaped interface 11 through the second rubber sealing gasket 30.

[0034] In this solution, the limiting ring 18 is connected through the surface of the second trumpet-shaped interface 13. When the second trumpet-shaped interface 13 is connected to one of the first trumpet-shaped interfaces 11, the arc surface of the limiting ring 18 also contacts the baffles 31 in the other two first trumpet-shaped interfaces 11, preventing the other two air intake pipes 6 from transporting gas to push the baffles 31, thereby improving the stability of the other two air intake pipes 6. Moreover, the limiting ring 18 also rotates synchronously with the air outlet pipe 4, so as to ensure that the limiting ring 18 performs a limiting operation on the other two baffles 31 when the second trumpet-shaped interface 13 rotates and connects with the other first trumpet-shaped interfaces 11.

[0035] In this solution, the first rubber sealing gasket 23 is bonded to the end of the second trumpet-shaped interface 13 . After the first rubber sealing gasket 23 contacts the end of the first trumpet-shaped interface 11 , it is used to provide sealing between the second trumpet-shaped interface 13 and the first trumpet-shaped interface 11 .

[0036] In this solution, the driving motor 5, the infrared transmitter 24, the infrared receiver 17 and the electromagnet 16 are all connected to the PLC controller through wires, and the PLC controller is connected to an external power supply through wires.

[0037] Working principle: when controlling the air outlet pipe 4 to be connected from one air inlet pipe 6 to another air inlet pipe 6, firstly energize the two electromagnets 16 to work, and the two electromagnets 16 generate magnetic force after being energized, and the two electromagnets 16 attract the iron blocks 25 through the magnetic force, and the two iron blocks 25 move toward the electromagnets 16 after being subjected to the force, so the two iron blocks 25 pull the two mounting rods 15 to drive the second trumpet-shaped interface 13 to separate from the first trumpet-shaped interface 11, and then control the driving motor 5 to be energized to work, the driving motor 5 drives the gear 8 to rotate, the gear 8 controls the ring gear 3 to rotate, the ring gear 3 drives the movable block 10 to rotate in the mounting shell 2, and the movable block 10 drives the air outlet pipe 4 to rotate synchronously, so as to complete the separation of the air outlet pipe 4 from the one air inlet pipe 6, as the air outlet pipe 4 continues to rotate, after the infrared transmitter 24 moves to the top of the infrared receiver 17 corresponding to the position of the air inlet pipe 6, the infrared rays emitted by the infrared transmitter 24 at this time irradiate the infrared receiver 17. On the receiver 17, the infrared receiver 17 feeds back the signal to the PLC controller, and the PLC controller controls the drive motor 5 to cut off the power. At this time, the second trumpet-shaped interface 13 corresponds to the position of the first trumpet-shaped interface 11 on the other air inlet pipe 6. Then, after the electromagnet 16 is controlled to be powered off, the compression spring 22 in the compressed state pushes the second trumpet-shaped interface 13 in the opposite direction toward the first trumpet-shaped interface 11 through its own elastic potential energy, and the second trumpet-shaped interface 13 drives the push rod 33 to push the baffle 31 through the connecting rod 34. After the baffle 31 is subjected to force, it drives the fixed rod 29 to rotate in the first trumpet-shaped interface 11. At the same time, the fixed rod 29 applies torque to the torsion spring 27. At this time, the torsion spring 27 is in an energy storage state, and a gap is generated between the baffle 31 and the first trumpet-shaped interface 11, which facilitates the gas to flow into the outlet pipe 4 from the space between the baffle 31 and the first trumpet-shaped interface 11, thereby facilitating the gas to be transported to the detector 36.

[0038] A method for splitting signals of a parallel multidimensional gas chromatograph of a parallel multidimensional gas chromatograph connection device comprises the following steps S1: The sample to be tested is sent into the gas chromatography system by an automatic sample injector. The target compound is separated in multiple stages on the parallel multi-dimensional gas chromatography and reaches the mass spectrometer detector respectively to obtain the coordinate data of the total ion flow diagram.

[0039] S2: According to the scanning frequency of the detector (the same as the switching frequency of the passage valve), the coordinate data obtained in step S1 is split into three groups of coordinate data, corresponding to the three passages respectively.

[0040] S3: Based on the three sets of coordinate data obtained in S2, three spectra are regenerated with retention time as the horizontal axis (X-axis) or ion abundance as the vertical axis (Y-axis).

[0041] S4: Based on the three sets of coordinate data obtained in S2, the three coordinates (x, y, z) of the target compound are found, corresponding to their retention times on the three chromatographic columns, and a three-dimensional scatter distribution diagram is drawn to achieve simple and intuitive visualization of the determination of the target compound.

[0042] Example 2 Signal Splitting Target compound: methyl oleate 200 ppb; Instrument: Gas chromatography-mass spectrometry (GC-MS); Gas chromatography conditions: vaporizer temperature: 250°C, injection volume: 2 µL, chromatographic column: CP Sil-88 (100m×0.25mm×0.20µm), temperature: 120°C→220°C programmed temperature, carrier gas pressure: constant pressure 38 psi.

[0043] Mass spectrometry conditions: Scan mode: selected ion scan (Sim), characteristic ions of methyl oleate: m / z=74, 69, 222, 264, scan period (total dwell time): 180 ms.

[0044] Access valve switching time: switching every 180 ms, consistent with the scanning frequency.

[0045] Total ion current diagram is attached Figure 8 The retention time of the target compound was 73.069 min.

[0046] The partial splitting generates the coordinate data of the full ion current of three corresponding pathways, see Table 1: Table 1 Split the coordinate points to generate the coordinate data of the full ion flow of 3 corresponding pathways (partial) Coordinate Point X(min) Y(Counts) aisle …… …… …… …… 500 40.092 477 A 501 40.095 473 B 502 40.097 471 C 503 40.1 473 A 504 40.103 474 B 505 40.105 471 C 506 40. 108 470 A 507 40.111 472 B 508 40.113 469 C 509 40.116 460 A 510 40.119 456 B …… …… …… …… 12231 73.018 1999 A 12232 73.021 2035 B 12233 73.024 2073 C 12234 73.026 2101 A 12235 73.029 2122 B 12236 73.032 2137 C 12237 73.035 2158 A 12238 73.037 2193 B 12239 73.040 2228 C …… …… …… …… 46151 164.909 694 A 46152 164.912 699 B 46153 164.915 704 C 46154 164.918 706 A 46155 164.920 701 B 46156 164.923 700 C 46157 164.926 707 A 46158 164.928 714 B …… …… …… …… Split the coordinate points to generate independent coordinates for three corresponding pathways, and reproduce the full ion current diagram as shown in the attached figure. Fig. 9 .

[0047] Example 3 Dual-path separation of compounds Target compounds: conjugated linoleic acid methyl ester (CLA n6 and CLA n7) 20 ppm; Instrument: Gas chromatography-flame ionization detector (GC-FID); Gas chromatography conditions: vaporizer temperature: 250°C, injection volume: 2 µL, column 1: DB FFAP (30m×0.25mm×0.25µm), column 2: DB-WAX UI (30m×0.25mm×0.25µm), temperature: 120°C→220°C program temperature rise, carrier gas pressure: constant pressure 32 psi; FID detector scan period: 100 ms.

[0048] Switching time of channel valve (dual channel): switching every 100 ms, consistent with the scanning frequency.

[0049] See attached for partial chromatogram Fig.10 ; The chromatograms corresponding to columns 1 and 2 after splitting and resetting are shown in the attached figure. Fig.11 .

[0050] As shown in the figure, column 1 has poor separation effect on conjugated linoleic acid methyl ester (CLA n6 and CLA n7), but column 2 achieves baseline separation with good peak shape. The parallel multidimensional chromatography system provides two sets of retention times as qualitative basis for their identification, further avoiding false positives.

[0051] Example 4 Three-way (multi-dimensional) assay of multiple compounds Injection compounds: 81 fatty acid methyl esters mixed standard (0.2~10 ppm); Instrument: Gas chromatography-mass spectrometry (GC-MS); Gas chromatography conditions: vaporizer temperature: 250°C, injection volume: 2 µL, column 1: BPX70 (100m×0.32mm×0.25µm), column 2: FAMEWAX (100m×0.25mm×0.25µm), column 3: CP Sil-88 (100m×0.25mm×0.20µm), temperature: 120°C→220°C programmed temperature, carrier gas pressure: constant pressure 38 psi.

[0052] Mass spectrometry conditions: Scan mode: selected ion scan (Sim), scan period (total dwell time): 150 ms.

[0053] Channel valve (three-channel) switching time: switching every 150 ms, consistent with the scanning frequency.

[0054] Total ion current diagram is attached Fig.12 , use the method of Example 1 to split the coordinate points of the chromatogram and reset it into independent chromatograms of the corresponding channels (chromatographic column 1, chromatographic column 2 and chromatographic column 3) as shown in the attached figure. Fig.13 .

[0055] like Fig.12 ,13 As shown in the figure, the separation of fatty acid methyl esters by the three columns is very different. For example, C12:1 c9 and isoC13:0 were not separated on column 1, but were baseline separated on columns 2 and 3; C14:1 t9 and iso C15:0 were baseline separated on column 1, but were not completely separated on columns 2 and 3; C16:1 t9 and iso C17:0 were not separated on column 1, were not completely separated on column 2, but were baseline separated on column 3. In the coordinate system, the retention time of each compound in the three channels is shown in Table 2: Table 2 Retention time of each compound in three channels

[0056] Based on the above data, a three-dimensional coordinate distribution diagram of retention time is drawn. See the attached Fig.14 , the separation and identification of compounds is simple, clear and more intuitive.

[0057] It can be seen from the data of the above embodiments that the parallel multi-dimensional gas chromatography connection device of the present invention has independent and co-frequency scanning of each chromatographic column, which realizes multi-dimensional detection in the true sense, and the qualitative properties are clear at a glance. It increases the basis for compound determination, achieves high selectivity, can increase the basis for compound determination, has high resolution, fault tolerance and selectivity, and has a wide range of applications.

[0058] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A parallel multi-dimensional gas chromatography connection device, Features: The invention comprises a housing (32), a pressure-dividing valve (7), a parallel multidimensional chromatographic pathway (21), a pathway valve (20) and a signal interaction system (12), wherein the pressure-dividing valve (7), the parallel multidimensional chromatographic pathway (21), the pathway valve (20) and the signal interaction system (12) are fixedly installed inside the housing (32); the pathway valve (20) is a multi-path valve capable of switching fluid paths, and is capable of switching parallel multidimensional chromatographic pathways; the parallel multidimensional chromatographic pathway (21) comprises a chromatographic column fixing mechanism and a chromatographic column; the injection port of the pressure-dividing valve (7) is connected to the injector (35), and the injection port of the pressure-dividing valve (7) is respectively connected to the parallel multidimensional chromatographic pathway (21) to connect chromatographic columns of different parameters in parallel, and to adjust the pressure drop entering each pathway; The outlet of the parallel multidimensional chromatographic pathway (21) is connected to the detector (36) via a pathway valve (20); the signal interaction system (12) electrically connects the pathway valve (20) and the detector (36) via a control line.

2. A parallel multi-dimensional gas chromatography connection device as claimed in claim 1, Features: The passage valve (20) comprises a mounting shell (2), a movable block (10) is installed through the top of the mounting shell (2), an air outlet pipe (4) is installed through the surface of the movable block (10), a plurality of air inlet pipes (6) are installed through the side of the mounting shell (2), one end of the air outlet pipe (4) and the plurality of air inlet pipes (6) extend into the interior of the mounting shell (2), a second trumpet-shaped interface (13) is movably installed at one end of the air outlet pipe (4), a first trumpet-shaped interface (11) is fixedly installed at one end of the plurality of air inlet pipes (6), and the second trumpet-shaped interface (13) is in close contact with the first trumpet-shaped interface (11).

3. A parallel multi-dimensional gas chromatography connection device as claimed in claim 2, Features: A gear ring (3) is fixedly mounted on the top of the movable block (10), a gear (8) is meshed on one side of the gear ring (3), a drive motor (5) is connected to the surface of the gear (8), and the housing of the drive motor (5) is mounted on the top of the mounting housing (2) via a motor bracket.

4. A parallel multi-dimensional gas chromatography connection device as claimed in claim 2, Features: A slide groove (9) is provided along the arc side surface of the movable block (10), a plurality of universal balls (1) arranged at equal angles are provided inside the slide groove (9), and a fixed housing of the universal balls (1) is mounted on the top of the mounting housing (2).

5. A parallel multi-dimensional gas chromatography connection device as claimed in claim 2, Features: One end of the air outlet pipe (4) is connected to a movable pipe (26) via a piston sealing ring, and one end of the movable pipe (26) is connected to a second trumpet-shaped interface (13). A fixed sleeve on the surface of the air outlet pipe (4) is provided with a fixed ring (14), and a movable sleeve on the surface of the movable pipe (26) is provided with a compression spring (22). Two ends of the compression spring (22) are respectively mounted on the surfaces of the fixed ring (14) and the second trumpet-shaped interface (13).

6. A parallel multi-dimensional gas chromatography connection device as claimed in claim 5, Features: Two symmetrically arranged mounting rods (15) are installed through the side of the fixing ring (14); one end of the mounting rod (15) is installed on the side of the second trumpet-shaped interface (13); an iron block (25) is installed on the other end of the mounting rod (15); an electromagnet (16) corresponding to the position is provided on one side of the iron block (25); a fixing member (19) is connected between the electromagnet (16) and the fixing ring (14).

7. A parallel multi-dimensional gas chromatography connection device as claimed in claim 2, Features: An infrared transmitter (24) is installed at the bottom of the air outlet duct (4), and a plurality of infrared receivers (17) are installed on the inner bottom surface of the mounting shell (2), wherein the positions of the infrared receivers (17) and the air inlet duct (6) correspond.

8. A parallel multi-dimensional gas chromatography connection device as claimed in claim 2, Features: A baffle (31) is provided inside one end of the first trumpet-shaped interface (11), a second rubber sealing gasket (30) is bonded to the arc surface of the baffle (31), the second rubber sealing gasket (30) is in contact with the inner surface of the first trumpet-shaped interface (11), fixing rods (29) are installed at the top and bottom of the baffle (31), a fixing block (28) is installed at one end of the two fixing rods (29), a torsion spring (27) is movably sleeved on the surface of the two fixing rods (29), the two ends of the torsion spring (27) are respectively installed on the surface of the fixing block (28) and the first trumpet-shaped interface (11), a connecting rod (34) is installed inside the second trumpet-shaped interface (13), and a push rod (33) corresponding to the position of the baffle (31) is installed on the side of the connecting rod (34).

9. A parallel multi-dimensional gas chromatography connection device as claimed in any one of claims 1 to 8, Features: The chromatographic column fixing mechanism is any one of a hook, a clamp ring, a cable tie, and a retention groove arranged in the shell body, which is convenient for replacing and fixing the chromatographic column.

10. A method for signal separation of parallel multidimensional gas chromatography using the parallel multidimensional gas chromatography connection device according to any one of claims 1 to 8, The following steps are involved: S1: The sample to be tested is sent into the gas chromatography system by an automatic sample injector, and the target compound is separated in multiple stages on the parallel multi-dimensional gas chromatography and reaches the detector respectively to obtain the coordinate data of the chromatogram or the total ion flow diagram; S2: splitting the coordinate data obtained in step S1 into three groups of coordinate data corresponding to the three passages respectively according to the detector scanning frequency which is the same as the switching frequency of the passage valve; S3: Based on the three sets of coordinate data obtained in S2, three spectra are regenerated with retention time as the horizontal axis as the X-axis and electrical signal or ion abundance as the vertical axis as the Y-axis; S4: Based on the three sets of coordinate data obtained in S2, the three coordinates x, y, and z of the target compound are found, corresponding to their retention times in the three chromatographic columns, and a three-dimensional scatter distribution diagram is drawn to achieve simple, intuitive, and visual determination of the target compound.

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