A gas chromatography sample injector and method

Abstract

The application relates to a gas chromatograph sample injector and method, which comprises a sample table, a sample rack, a three-axis sliding table assembly and a sample injection assembly. The sample rack is placed on the table top of the sample table, and a plurality of sample bottles are placed on the sample rack. The three-axis sliding table assembly comprises a first sliding table, a second sliding table and a third sliding table arranged in three dimensions along the axial direction of the sample rack. The first sliding table is fixedly arranged. The second sliding table is used for reciprocating sliding along the X-axis and Y-axis directions. The third sliding table is used for reciprocating sliding along the Z-axis direction. The sample injection assembly comprises a sample injection needle used for connecting a sample injection port of a gas chromatograph. The sample injection needle is installed on the third sliding table and is used for penetrating into the sample bottles. The gas chromatograph sample injector can be directly installed above the sample injection port of the gas chromatograph, can effectively save the table top space, can control the sample injection needle to continuously sample a plurality of sample bottles in sequence, can effectively improve the sample injection efficiency of the gas, and can be connected with a syringe pump to realize sample injection of liquid samples.

Description

Technical Field

[0001] This invention relates to the field of analytical testing technology, specifically to a gas chromatograph injector and method. Background Technology

[0002] With the continuous development of technology, autosamplers have become standard equipment in analytical instruments due to their characteristics of continuous automatic sample injection, unattended operation, and improved work efficiency. As an auxiliary component of instruments, autosamplers have become standard equipment in analytical instruments because they can replace manual labor, provide continuous automatic sample injection, and improve work efficiency. However, for gas analysis, due to the special nature of gas samples, there are relatively few suitable autosamplers, and manual injection using syringes is the primary method. Therefore, there is a need to design an autosampler for gas samples suitable for gas chromatographs. Summary of the Invention

[0003] The purpose of this invention is to provide a gas chromatograph injector and method to solve the problem of low gas injection efficiency in the prior art due to the manual injection of gas samples using syringes during gas analysis.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a gas chromatograph injector, including a sample stage, a sample holder, a triaxial slide assembly, and an injection assembly;

[0006] The sample rack is placed on the sample stage, and several sample bottles are placed on the sample rack.

[0007] The triaxial slide assembly includes a first slide, a second slide, and a third slide arranged in three dimensions based on the sample holder. The first slide is fixedly set, the second slide is slidably connected to the first slide and is used for reciprocating sliding along the X-axis and Y-axis directions, and the third slide is slidably connected to the second slide and is located above the sample holder and is used for reciprocating sliding along the Z-axis direction.

[0008] The injection assembly includes an injection needle, which is mounted on the third slide and used to insert into the sample vial. The injection needle is connected to an external analytical instrument via an injection tubing.

[0009] Furthermore, the gas chromatograph injector also includes a side positioning bracket, which includes a side plate, a lower fixing plate, an upper fixing plate, and a support plate. The side plate is vertically arranged, and the sample stage is fixedly connected to one side of the side plate. The lower fixing plate and the upper fixing plate are both arranged parallel to the sample stage surface. The lower fixing plate is fixed to the top of the side plate and forms a suspension support with a "Γ" shaped cross-section. The upper fixing plate is arranged above the lower fixing plate, and the upper fixing plate and the lower fixing plate are connected by the vertically arranged support plate. The first slide is fixed to the top surface of the upper fixing plate.

[0010] The lower fixing plate is a "Γ"-shaped planar plate structure, which includes a long side plate and a short side plate. One side of the long side plate is connected to the side plate, and a first fixing through hole is opened in the middle of the long side plate. The short side plate is located on the other side of the long side plate, and a second fixing through hole is opened on the end of the short side plate.

[0011] Furthermore, a first slider is slidably connected to the first slide via an electronically controlled drive, a second slider is slidably connected to the second slide via an electronically controlled drive, the second slider is fixedly connected to the first slider, a third slider is slidably connected to the third slide via an electronically controlled drive, the injection needle is fixedly connected to the third slider, and the tip of the injection needle is vertically downward.

[0012] Each of the three slides is equipped with an electrically controlled drive mechanism, which includes a lead screw and a drive motor. The drive motor is fixed at the end of the slide, and the lead screw is installed inside the slide along the axial direction of the slide. One end of the lead screw is connected to the output end of the drive motor, and the slider on the slide is helically connected to the lead screw.

[0013] Furthermore, the injection assembly also includes a solenoid valve and an injection pump. Both the solenoid valve and the injection pump are mounted on the side of the support plate. The solenoid valve has an inlet, a first outlet, and a second outlet. The inlet is connected to the injection needle via an injection line. The first outlet is connected to the injection port of the gas chromatograph via another injection line. The second outlet is connected to the injection pump via a third injection line.

[0014] The syringe pump includes a slide, a retaining clamp, a syringe, a plunger seat, an extension rod, and a cylindrical pin. The slide is mounted on the side of the support plate. The retaining clamp is fixed to one end of the slide. The syringe is horizontally positioned above the slide, and the injection end of the syringe is held and fixed by the retaining clamp. The plunger seat is slidably connected to the slide on one side of the retaining clamp, and a limiting hole is provided on the plunger seat for the syringe to pass through laterally. The extension rod is parallel to the syringe and is positioned on the side of the plunger seat away from the retaining clamp. One extension rod is provided on each side of the syringe. One end of the extension rod is fixedly connected to the plunger seat, and the other ends of the two extension rods are connected by the cylindrical pin, which is fixedly connected to the piston end of the syringe.

[0015] Furthermore, the gas chromatograph injector also includes a first control box, which is installed at the bottom of the sample stage, so that the "Γ"-shaped suspension support is used to suspend on the left side of the top injection port of the analytical instrument, and a support component for supporting on the table is provided on the side positioning bracket.

[0016] The first control box has an integrated first main control circuit board and a first interface board inside, and a control panel is installed on the front outer wall of the first control box. The control panel is obliquely arranged, and the signal output terminal of the control panel is electrically connected to the signal input terminal of the first main control circuit board. The signal output terminal of the first main control circuit board is electrically connected to each of the drive motors, solenoid valves and injection pumps through the first interface board.

[0017] The support assembly includes a first support rod and a second support rod that are vertically supported on the ground. The top end of the first support rod is fixed to the bottom of the side plate, and several first support rods are arranged along the length of the side plate. The top end of the second support rod is fixed to the bottom plate surface of the upper fixed plate, and the second support rod is located near the second slide. The bottom of both the first support rod and the second support rod is provided with threaded feet.

[0018] Furthermore, the gas chromatograph injector also includes a second control box, which is located below the lower fixed plate and fitted into the "Γ"-shaped suspension support. The top wall of the second control box is fixedly connected to the bottom plate of the lower fixed plate, so that the gas chromatograph injector can be placed on a table.

[0019] Furthermore, a needle washer is fixed to the sample stage at the initial position of the injection needle. The needle washer has a vertically upward insertion hole, and the bottom of the needle washer is connected to a needle washer solution via a peristaltic pump.

[0020] Furthermore, a number of positioning pins are fixedly attached to the surface of the sample stage, and a recessed hole is formed at the bottom of the sample holder for the positioning pins to wedge into.

[0021] Based on the gas chromatograph injector described above, the present invention also provides an automated sample injection method, including a method for injecting gas samples:

[0022] Arrange several sample bottles containing the gas to be tested in order on the sample rack, and place the sample rack on the sample stage;

[0023] After confirming that the sample holder is in place, set the initial sampling position of the injection needle, the number of samples injected, and the injection time;

[0024] According to the set parameters, the solenoid valve is controlled to switch to the state where the injection needle and the injection port of the gas chromatograph are connected, and the second slide is controlled to move along the X-axis and Y-axis so that the third slide is located at the set initial sampling position.

[0025] Once the third slide is in position, control the third slider to descend vertically until it drives the injection needle to pierce the sample vial. The sample is then injected into the analytical instrument through the injection line.

[0026] After the gas chromatograph completes data acquisition, it controls the second slide to move along the X and Y axes, so that the third slide is located at the next sampling position and the next sample vial is sampled, until the set number of samples is completed.

[0027] Furthermore, it also includes methods for liquid sample injection:

[0028] Arrange several sample bottles containing liquid in sequence on the sample rack, and place the sample rack on the sample stage;

[0029] After confirming that the sample holder is in place, set the initial position of the injection needle, the number of samples to be injected, and the injection volume;

[0030] According to the set parameters, the solenoid valve is controlled to switch to the state where the injection needle and injection pump interface are connected, and the second slide is controlled to move along the X and Y axes so that the third slide is located at the set initial position.

[0031] Once the third slide is in position, control the third slider to descend vertically until it drives the injection needle to pierce the sample vial, and control the injection pump to draw the liquid in the sample vial into the injection pump.

[0032] Once the set aspiration volume is reached, the control solenoid valve switches to the state where the injection pump and the gas chromatograph's injection port are connected, and the injection pump discharges the liquid in the syringe according to the set injection volume.

[0033] Control the second slide to move along the X and Y axes, so that the third slide is positioned in the syringe washer position to clean the injection needle and the syringe pump;

[0034] Continue to control the second slide to move along the X and Y axes, so that the third slide is located at the next sample position and the next operation is performed until the set number is completed.

[0035] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0036] By setting up a sample stage, sample holder, triaxial slide assembly, and injection assembly, the three slides arranged in three dimensions based on the sample holder move to control the injection needle to continuously sample and inject multiple injection vials, thereby effectively improving the gas injection efficiency. Furthermore, by arranging the triaxial slide assembly above the sample holder, after installing the gas chromatograph injector above the injection port of the gas chromatograph, stage space can be effectively saved. This allows for both gas injection and injection of liquid samples by connecting an injection pump. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0038] Figure 1 This is a structural schematic diagram of an assembly method one of the gas chromatograph autosamplers provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of a second assembly method for an automated gas chromatograph provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the side positioning support of an automatic gas chromatograph provided in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the injection pump of an autosampler for gas chromatography provided in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of a support assembly for an automated gas chromatograph provided in an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the sample stage structure of an automatic gas chromatograph provided in an embodiment of the present invention.

[0044] The markings in the attached diagram are as follows:

[0045] 1. Sample stage; 11. Needle washer; 12. Positioning pin; 2. Sample holder; 3. Three-axis slide assembly; 31. First slide; 311. First slider; 32. Second slide; 321. Second slider; 33. Third slide; 331. Third slider; 4. Injection assembly; 41. Injection needle; 42. Solenoid valve; 43. Injection pump; 431. Slide; 432. Fixing clamp; 433. Syringe; 434. Push rod seat; 435. Extension rod; 436. Cylindrical pin; 5. Sample vial; 6. Side positioning bracket; 61. Side plate; 62. Lower fixing plate; 63. Upper fixing plate; 64. Support plate; 7. First control box; 71. First control panel; 8. Support assembly; 81. First support rod; 82. Second support rod. Detailed Implementation

[0046] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0047] Currently, gas sample introduction efficiency is low due to the manual injection of gas samples using syringes during gas analysis. This invention provides a gas chromatograph injector and method, including a sample stage, a sample holder, a triaxial slide assembly, and an injection assembly. The sample holder is placed on the sample stage and holds several sample vials. The triaxial slide assembly includes a first slide, a second slide, and a third slide arranged axially in three dimensions based on the sample holder. The first slide is fixed, the second slide reciprocates along the X and Y axes, and the third slide reciprocates along the Z axis. The injection assembly includes an injection needle for external analytical instruments, mounted on the third slide and used to insert into the sample vials. This invention enables the injection needle to sequentially and continuously sample and inject multiple vials, thereby effectively improving gas sample introduction efficiency.

[0048] The present invention will be described in detail below through embodiments.

[0049] Example

[0050] like Figure 1 and Figure 2 As shown, the present invention provides a gas chromatograph injector, including a sample stage 1, a sample holder 2, a triaxial slide assembly 3, and an injection assembly 4, the specific configuration of which is as follows:

[0051] The sample holder 2 is placed on the surface of the sample stage 1, and several sample vials 5 are placed on the sample holder 2. The triaxial slide assembly 3 includes a first slide 31, a second slide 32, and a third slide 33 arranged axially based on the sample holder 2. Specifically, the first slide 31 is arranged horizontally along the X-axis, the second slide 32 is arranged horizontally along the Y-axis, and the third slide 33 is arranged vertically along the Z-axis. The first slide 31 is fixedly set, the second slide 32 is slidably connected to the first slide 31, and the second slide 32 is used for reciprocating sliding along the X-axis and Y-axis. The third slide 33 is slidably connected to the second slide 32, and the third slide 33 is located above the sample holder 2 and is used for reciprocating sliding along the Z-axis. The injection assembly 4 includes an injection needle 41, which is mounted on the third slide 33 and used to vertically insert into the sample vial 5. The injection needle 41 is connected to an analytical instrument via an injection tubing, preferably a gas chromatograph. By using this structure, the movement of three slides arranged in three dimensions along the sample holder 2 can control the injection needle 41 to continuously sample and inject multiple injection bottles 5, thereby effectively improving the gas injection efficiency.

[0052] Furthermore, combined Figure 3 As shown, the gas chromatograph injector also includes a side positioning bracket 6. The side positioning bracket 6 includes a side plate 61, a lower fixing plate 62, an upper fixing plate 63, and a support plate 64. The side plate 61 is vertically arranged, and the sample stage 1 is fixedly connected to one side of the side plate 61. The lower fixing plate 62 and the upper fixing plate 63 are both parallel to the surface of the sample stage 1. The lower fixing plate 62 is fixed to the top of the side plate 61 and forms a suspension support with a "Γ"-shaped cross-section. The upper fixing plate 63 is positioned above the lower fixing plate 62, and the upper fixing plate 63 and the lower fixing plate 62 are connected by the vertically arranged support plate 64. The first slide 31 is fixed to the top surface of the upper fixing plate 63. With this structure, the side positioning bracket 6 can be installed above the injection port of the analytical instrument, and the side positioning bracket 6 provides support for the triaxial slide assembly 3, allowing the triaxial slide assembly 3 to be stably positioned above the sample stage 1, ensuring a more compact structure for the gas chromatograph injector of this invention.

[0053] Furthermore, the lower fixing plate 62 is a "Γ"-shaped planar plate structure, comprising a long side plate and a short side plate. One side of the long side plate is connected to the side plate 61, and a first fixing through hole is provided in the middle of the long side plate surface. The short side plate is located on the other side of the long side plate, and a second fixing through hole is provided on the end of the short side plate surface. With this structure, using the "Γ"-shaped planar lower fixing plate 62, the lower fixing plate 62 can be fixed to the gas chromatograph by screws through the two through holes reserved at the end of the short side plate and in the middle of the long side plate.

[0054] Furthermore, a first slider 311 is slidably connected to the first slide 31 via an electronically controlled drive, and a second slider 321 is slidably connected to the second slide 32 via an electronically controlled drive. The second slider 321 is fixedly connected to the first slider 311. A third slider 331 is slidably connected to the third slide 33 via an electronically controlled drive, and the injection needle 41 is fixedly connected to the third slider 331 with its tip pointing vertically downwards. With this structure, utilizing the fixed connection between the second slider 321 and the first slider 311, the second slide 32 can reciprocate on the first slide 31 along the first slide 31. Simultaneously, the second slide 32 can reciprocate along the Y-axis based on the fixed second slider 321, thus allowing the second slide 32 to move simultaneously along the X and Y axes. At this time, the third slider 331 is controlled to reciprocate on the third slide 33 to ensure the accuracy of the injection needle sampling.

[0055] As described above, each of the three slides is equipped with an electrically controlled drive mechanism, which includes a lead screw and a drive motor. The drive motor is fixed to the end of the slide, and the lead screw is installed inside the slide along its axial direction. One end of the lead screw is connected to the output end of the drive motor, and the slider on the slide is helically connected to the lead screw. This structure allows for the control of the movement of the three sliders via electrical control, thereby enabling automatic sample injection and sampling by the injection needle 41.

[0056] Furthermore, looking back Figure 2 The injection assembly 4 also includes a solenoid valve 42 and a syringe pump 43. Both the solenoid valve 42 and the syringe pump 43 are mounted on the side of the support plate 64. The solenoid valve 42 has an inlet, a first outlet, and a second outlet. The inlet is connected to the injection needle 41 via an injection line, the first outlet is connected to the injection port of the gas chromatograph via another injection line, and the second outlet is connected to the syringe pump 43 via a third injection line. This structure allows the solenoid valve 42 to switch the injection needle 41 line to the direction of the syringe pump 43 before injection, facilitating liquid injection and thus improving the versatility of the gas chromatograph injector of this invention.

[0057] As mentioned above, combined Figure 4As shown, the syringe pump 43 includes a slide 431, a retaining clamp 432, a syringe 433, a plunger seat 434, an extension rod 435, and a cylindrical pin 436. The slide 431 is mounted on the side of the support plate 64, and the retaining clamp 432 is fixed to one end of the slide 431. The syringe 433 is horizontally positioned above the slide 431, and its injection end is held and fixed by the retaining clamp 432. The plunger seat 434 is slidably connected to the slide 431 on one side of the retaining clamp 432, and a limiting hole is provided on the plunger seat 434 for the syringe 433 to pass through laterally. The extension rod 435 is parallel to the syringe 433 and is located on the side of the plunger seat 434 away from the retaining clamp 432. One extension rod 435 is provided on each side of the syringe 433. One end of the extension rod 435 is fixedly connected to the push rod seat 434, and the other ends of the two extension rods 435 are connected by a cylindrical pin 436, which is fixedly connected to the piston end of the syringe 433. With this structure, the extension rod 435 can be driven to move the piston end of the syringe 433 by controlling the sliding of the push rod seat 434, thereby enabling the syringe 433 to sample the liquid in the sample vial 5. Preferably, the push rod seat 434 is driven by a motor.

[0058] One preferred embodiment includes mounting the sample stage 1 on the analytical instrument platform in the following manner:

[0059] Combination Figure 1 , Figure 2 and Figure 3 As shown, the gas chromatograph injector also includes a first control box 7. The first control box 7 is installed at the bottom of the sample stage 1, and a support assembly 8 for supporting it on the tabletop is provided on the side positioning bracket 6. By suspending the side positioning bracket 6 on the left side of the top injection port of the analytical instrument, the sample stage 1, sample holder 2, and triaxial slide assembly 3 are all suspended on the left side of the analytical instrument, thus effectively saving tabletop space.

[0060] As described above, the first control box 7 internally houses an integrated first main control circuit board and a first interface board. The integrated circuit of the first main control circuit board is a conventional electrical component control circuit in the art and is not within the scope of protection of this invention. A control panel 71 is installed on the outer wall of the first control box. The control panel 71 is angled and its angle is adjustable. The signal output terminal of the control panel 71 is electrically connected to the signal input terminal of the first main control circuit board. The signal output terminal of the first main control circuit board is electrically connected to each drive motor, solenoid valve 42, and syringe pump 43 through the first interface board. With this structure, based on the input of set parameters to the control panel 71, each drive motor, solenoid valve 42, and syringe pump 43 can be automatically executed, thereby automatically controlling the injection needle 41 to start injection from a designated position. Furthermore, it can communicate with the analytical instrument via signal lines, and perform the injection operation when the analytical instrument is ready, further ensuring the success rate of injection.

[0061] like Figure 5 As shown, the support assembly 8 includes a first support rod 81 and a second support rod 82 vertically supported on the ground. The top end of the first support rod 81 is fixed to the bottom of the side plate 61, and several first support rods 81 are arranged along the length of the side plate 61. The top end of the second support rod 82 is fixed to the bottom surface of the upper fixed plate 63, and the second support rod 82 is positioned close to the second slide 32. With this structure, when the "Γ"-shaped suspension support is suspended at the sample inlet of the analytical instrument, the lower fixed plate 62 is fixed to the sample inlet of the analytical instrument with screws, so that the entire side positioning bracket 6 stably provides support for the sample stage 1 and the triaxial slide assembly 3 under the action of the first support rod 81 and the second support rod 82. Preferably, the bottom of both the first support rod 81 and the second support rod 82 is provided with threaded feet to facilitate adjustment of the height of the support rods.

[0062] refer to Figure 2 As shown, a preferred embodiment includes a second method where the sample stage 1 is placed on a table:

[0063] The gas chromatograph injector also includes a second control box, which is located below the lower fixed plate 62 and is fitted into the "Γ"-shaped suspension support. The top wall of the second control box is fixed to the bottom plate of the lower fixed plate. After removing the support assembly, the gas chromatograph injector of the present invention can be placed directly on the table for use. At this time, the second control box provides support for the side positioning bracket 6 at the "Γ"-shaped suspension support.

[0064] It should be noted that the gas chromatograph injector of the present invention includes only one control box, and the first control box and the second control box mentioned above are only used to distinguish the different installation methods of the control box.

[0065] Furthermore, combined Figure 1 and Figure 6 As shown, a needle washer 11 is fixedly attached to the sample stage 1 at the initial position of the injection needle 41. The needle washer 11 has a vertically upward insertion hole, and the bottom of the needle washer 41 is connected to the needle washer solution via a peristaltic pump. With this structure, the injection needle 41 can be cleaned on the stage surface by the needle washer 11 before and after sampling, so as to avoid contamination of the test liquid.

[0066] Furthermore, combined Figure 1 and Figure 6 As shown, several positioning pins 12 are fixedly attached to the surface of the sample stage 1, and a recessed hole is formed at the bottom of the sample holder 2 for the positioning pins 12 to wedge into. With this structure, when the sample holder 2 is placed on the surface of the sample stage 1, the recessed hole at the bottom of the sample holder 2 aligns with the positioning pins 12 on the surface of the sample stage 1, thereby positioning the sample holder 2 on the surface of the sample stage 1 and preventing the sample holder 2 from shifting during operation.

[0067] Based on the gas chromatograph injector described above, the present invention also provides an automated sample injection method, including a method for injecting gas samples:

[0068] Several sample bottles 5 containing the gas to be tested are placed in sequence on the sample rack 2, and the sample rack 2 is placed on the sample stage 1.

[0069] After confirming that the sample holder 2 is in place, set the initial sampling position, injection quantity, and injection time of the injection needle 41;

[0070] According to the set parameters, the solenoid valve 42 is switched to the state where the injection needle 41 and the injection port of the gas chromatograph are connected, and the second slide 32 is controlled to move along the X-axis and Y-axis so that the third slide 33 is located at the set initial sampling position.

[0071] After the third slide 33 is in position, control the third slider 331 to descend vertically until it drives the injection needle 41 to pierce the sample vial 5. The sample is then injected into the gas chromatograph through the injection tube.

[0072] After the gas chromatograph completes data acquisition, it controls the second slide 32 to move along the X and Y axes, so that the third slide 33 is located at the next sampling position and the next sample vial 5 is sampled, until the set number of samples is completed.

[0073] Furthermore, it also includes methods for liquid sample injection:

[0074] Arrange several sample bottles 5 containing liquid in sequence on the sample rack 2, and place the sample rack 2 on the sample stage 1;

[0075] After confirming that the sample holder 2 is in place, set the initial position of the injection needle 41, the number of samples injected, and the injection volume;

[0076] According to the set parameters, the solenoid valve 42 is controlled to switch to the interface connection state between the injection needle 41 and the injection pump 43, and the second slide 32 is controlled to move along the X-axis and Y-axis so that the third slide 33 is located at the set initial position.

[0077] After the third slide 33 is in position, control the third slider 331 to descend vertically until it drives the injection needle 41 to pierce the sample bottle 5, and control the injection pump 43 to draw the liquid in the sample bottle 5 into the injection pump 43.

[0078] Once the set aspiration volume is reached, the control solenoid valve 42 switches to the state where the syringe pump 43 and the gas chromatograph injection port are connected, and the control syringe pump 43 discharges the liquid in the syringe 433 according to the set injection volume.

[0079] Control the second slide 32 to move along the X and Y axes so that the third slide is positioned at the needle washer 11 to clean the injection needle 41 and the injection pump 43;

[0080] Continue to control the second slide 32 to move along the X and Y axes, so that the third slide is located at the next sample position and the next operation is performed until the set number is completed.

[0081] The gas chromatograph injector provided in this invention has the following beneficial effects:

[0082] 1. The gas chromatograph injector of the present invention utilizes the movement of three sliding stages arranged in three dimensions along the sample holder 2 to control the injection needle 41 to continuously sample and inject multiple injection bottles 5 in sequence, thereby effectively improving the gas injection efficiency.

[0083] 2. The gas chromatograph injector of the present invention can be suspended at the injection port of the analytical instrument by the side positioning bracket 6, saving table space, or it can be placed directly on the table of the analytical instrument for use.

[0084] 3. The gas chromatograph injector of the present invention can realize gas injection and can also be connected to the syringe pump 43 to realize liquid sample injection.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas chromatograph injector, characterized in that: The gas chromatograph injector includes a sample stage, a sample holder, a triaxial slide assembly, and an injection assembly; The sample rack is placed on the sample stage, and several sample bottles are placed on the sample rack. The triaxial slide assembly includes a first slide, a second slide, and a third slide arranged in three dimensions based on the sample holder. The first slide is fixedly set, the second slide is slidably connected to the first slide and is used for reciprocating sliding along the X-axis and Y-axis directions, and the third slide is slidably connected to the second slide and is located above the sample holder and is used for reciprocating sliding along the Z-axis direction. The injection assembly includes an injection needle, which is mounted on the third slide and used to insert into the sample vial. The injection needle is connected to an external analytical instrument via an injection tubing. The gas chromatograph injector also includes a side positioning bracket, which includes a side plate, a lower fixing plate, an upper fixing plate, and a support plate. The side plate is vertically arranged, and the sample stage is fixedly connected to one side of the side plate. The lower fixing plate and the upper fixing plate are both arranged parallel to the sample stage surface. The lower fixing plate is fixed to the top of the side plate and forms a suspension support part with a "Γ" shaped cross section. The upper fixing plate is arranged above the lower fixing plate, and the upper fixing plate and the lower fixing plate are connected by the vertically arranged support plate. The first slide is fixed to the top plate surface of the upper fixing plate. The lower fixing plate is a "Γ" shaped planar plate structure, which includes a long side plate and a short side plate. One side of the long side plate is connected to the side plate, and a first fixing through hole is opened in the middle of the plate surface of the long side plate. The short side plate is located on the other side of the long side plate, and a second fixing through hole is opened on the plate surface at the end of the short side plate. The injection assembly also includes a solenoid valve and an injection pump. Both the solenoid valve and the injection pump are mounted on the side of the support plate. The solenoid valve has an inlet, a first outlet, and a second outlet. The inlet is connected to the injection needle through an injection line. The first outlet is connected to the injection port of the gas chromatograph through another injection line. The second outlet is connected to the injection pump through a third injection line. The syringe pump includes a slide, a retaining clamp, a syringe, a plunger seat, an extension rod, and a cylindrical pin. The slide is mounted on the side of the support plate. The retaining clamp is fixed to one end of the slide. The syringe is horizontally positioned above the slide, and the injection end of the syringe is held and fixed by the retaining clamp. The plunger seat is slidably connected to the slide on one side of the retaining clamp, and a limiting hole is provided on the plunger seat for the syringe to pass through laterally. The extension rod is parallel to the syringe and is positioned on the side of the plunger seat away from the retaining clamp. One extension rod is provided on each side of the syringe. One end of the extension rod is fixedly connected to the plunger seat, and the other ends of the two extension rods are connected by the cylindrical pin, which is fixedly connected to the piston end of the syringe.

2. The gas chromatograph injector according to claim 1, characterized in that: A first slider is slidably connected to the first slide via an electronically controlled drive. A second slider is slidably connected to the second slide via an electronically controlled drive. The second slider is fixedly connected to the first slider. A third slider is slidably connected to the third slide via an electronically controlled drive. The injection needle is fixedly connected to the third slider, and the tip of the injection needle is vertically downward. Each of the three slides is equipped with an electrically controlled drive mechanism, which includes a lead screw and a drive motor. The drive motor is fixed at the end of the slide, and the lead screw is installed inside the slide along the axial direction of the slide. One end of the lead screw is connected to the output end of the drive motor, and the slider on the slide is helically connected to the lead screw.

3. A gas chromatograph injector according to claim 2, characterized in that: The gas chromatograph injector also includes a first control box, which is installed at the bottom of the sample stage, so that the "Γ"-shaped suspension support is used to suspend on the left side of the top injection port of the analytical instrument, and a support component for supporting on the table is provided on the side positioning bracket. The first control box has an integrated first main control circuit board and a first interface board inside, and a control panel is installed on the front outer wall of the first control box. The control panel is obliquely arranged, and the signal output terminal of the control panel is electrically connected to the signal input terminal of the first main control circuit board. The signal output terminal of the first main control circuit board is electrically connected to each of the drive motors, solenoid valves and injection pumps through the first interface board. The support assembly includes a first support rod and a second support rod that are vertically supported on the ground. The top end of the first support rod is fixed to the bottom of the side plate, and several first support rods are arranged along the length of the side plate. The top end of the second support rod is fixed to the bottom plate surface of the upper fixed plate, and the second support rod is located near the second slide. The bottom of both the first support rod and the second support rod is provided with threaded feet.

4. A gas chromatograph injector according to claim 2, characterized in that: The gas chromatograph injector also includes a second control box, which is located below the lower fixed plate and is fitted into the "Γ"-shaped suspension support. The top wall of the second control box is fixedly connected to the bottom plate of the lower fixed plate, so that the gas chromatograph injector can be placed on a table.

5. A gas chromatograph injector according to claim 1, characterized in that: A needle washer is fixed to the sample stage at the initial position of the injection needle. The needle washer has a vertically upward insertion hole, and the bottom of the needle washer is connected to the needle washer solution via a peristaltic pump.

6. A gas chromatograph injector according to claim 1, characterized in that: Several positioning pins are fixed to the surface of the sample stage, and a recessed hole is formed at the bottom of the sample holder for the positioning pins to wedge into.

7. An automated sample injection method, employing a gas chromatograph injector as described in any one of claims 1-6, characterized in that, The method includes a method for introducing gas samples: Arrange several sample bottles containing the gas to be tested in order on the sample rack, and place the sample rack on the sample stage; After confirming that the sample holder is in place, set the initial sampling position of the injection needle, the number of samples injected, and the injection time; According to the set parameters, the solenoid valve is controlled to switch to the state where the injection needle and the injection port of the gas chromatograph are connected, and the second slide is controlled to move along the X-axis and Y-axis so that the third slide is located at the set initial sampling position. Once the third slide is in position, control the third slider to descend vertically until it drives the injection needle to pierce the sample vial. The sample is then injected into the analytical instrument through the injection line. After the gas chromatograph completes data acquisition, it controls the second slide to move along the X and Y axes, so that the third slide is located at the next sampling position and the next sample vial is sampled, until the set number of samples is completed.

8. The automatic sample introduction method according to claim 7, characterized in that, It also includes methods for liquid sample injection: Arrange several sample bottles containing liquid in sequence on the sample rack, and place the sample rack on the sample stage; After confirming that the sample holder is in place, set the initial position of the injection needle, the number of samples to be injected, and the injection volume; According to the set parameters, the solenoid valve is controlled to switch to the state where the injection needle and injection pump interface are connected, and the second slide is controlled to move along the X and Y axes so that the third slide is located at the set initial position. Once the third slide is in position, control the third slider to descend vertically until it drives the injection needle to pierce the sample vial, and control the injection pump to draw the liquid in the sample vial into the injection pump. Once the set aspiration volume is reached, the control solenoid valve switches to the state where the injection pump and the gas chromatograph's injection port are connected, and the injection pump discharges the liquid in the syringe according to the set injection volume. Control the second slide to move along the X and Y axes, so that the third slide is positioned in the syringe washer position to clean the injection needle and the syringe pump; Continue to control the second slide to move along the X and Y axes, so that the third slide is located at the next sample position and the next operation is performed until the set number is completed.

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