A syringe for trace substance analysis
Through the syringe and microporous filtration assembly driven by electric push rod, the problems of liquid loss and difficulty in filtration of foreign matter in trace substance analysis are solved, and efficient liquid filtration and column prevention of blockage are achieved.
Patent Information
- Application Number
- CN201910567871.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-06-27
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2039-06-27
AI Technical Summary
Prior Art In the analysis of trace substances, injection liquid is easily lost when introduced into the lined tube, and it is difficult to effectively filter foreign matter and particles, resulting in clogging of the chromatographic column.
The syringe driven by an electric push rod is used to change the pressure of the solution suction chamber to achieve suction and filtration of liquids. Combined with the microporous filtration assembly and drainage tube, ensure that the liquid enters the injection bottle and filters foreign matter.
It effectively avoids liquid loss, improves filtration effect, prevents chromatographic column blockage, and achieves accurate operation of trace liquids.
Smart Images
Figure CN110174485B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a syringe, in particular to a syringe used for trace substance analysis. Background Art
[0002] With the development of agricultural industrialization, the production of agricultural products is increasingly dependent on substances such as pesticides, antibiotics and hormones to obtain more industrial value. Due to excessive use, the levels of corresponding substances in the environment and agricultural products exceed the limit, which seriously threatens the quality and safety of agricultural products. Therefore, to ensure the quality and safety of agricultural products, accurate analysis of trace substance levels in the environment or agricultural products is the basis, and pretreatment methods are the prerequisite.
[0003] Hormones in aquatic products are mainly divided into exogenous and endogenous hormones. Improper use or abuse of exogenous hormones leads to their residues in aquatic products, causing certain harm to human health. The content of endogenous hormones in aquatic products is related to the growth environment of the aquatic products themselves, the bait they eat, and the method of ripening (usually the level of endogenous hormones is low, at the level of one part per million, which belongs to the category of trace analysis), and reasonable and efficient pretreatment methods are the prerequisite for trace substance analysis.
[0004] According to the existing standard GB / T21981-2008 "Detection Method for Hormone Residues in Animal Food. Liquid Chromatography-Mass Spectrometry / Mass Spectrometry", gas chromatograph or liquid phase spectrometer can be used for detection. The analysis steps can be divided into: sample preparation, extraction, purification, concentration and determination. After concentration, it is generally necessary to make a fixed volume in a 2ml automatic sampler sample bottle for chromatographic determination. If the sample solution after the fixed volume is determined, it must be filtered through a 0.22μm filter membrane before determination to remove tiny particles in the solvent to avoid clogging the chromatographic column.
[0005] However, for hormone or pesticide residues, especially trace substance detection, because of their low background concentration, the volume of the fixed volume will be reduced accordingly during the fixed volume to increase the concentration of the solution to be tested for the convenience of quantitative analysis. However, due to the small sample volume of the solvent, the liquid level cannot be raised, which is not convenient for the chromatograph to perform detection and analysis. Therefore, the prior art adopts the method of adding a sample liner tube in the injection bottle to raise the liquid level of the solvent. The liner tube is located in the injection bottle, and the opening direction of the liner tube is the same as the opening direction of the injection bottle. The inner diameter of the tube mouth of the liner tube is smaller than that of the injection bottle, so the liquid level of the solvent can be raised, which is convenient for the chromatograph to perform detection and analysis. However, because the tube mouth of the liner tube becomes smaller, the liquid is very likely to stay at the tube mouth of the liner tube due to its own tension when entering the liner tube, which causes the subsequent solution to be unable to enter the liner tube, or even overflow, so there is room for improvement. Summary of the invention
[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a syringe for trace substance analysis, which can prevent the injection liquid from being lost when introduced into the inner liner tube, and at the same time can filter foreign matter and particles in the injection liquid, with good filtering effect and avoiding clogging of the chromatographic column.
[0007] The present invention adopts the following technical scheme: a syringe for trace substance analysis, comprising an injection device and a filter, the injection device comprising an electric push rod, a fixed block for installing the electric push rod, an injection cavity and an injection and suction joint which are arranged in sequence from top to bottom, one side of the fixed block is provided with a storage hole for accommodating the electric push rod, the injection cavity has a solution suction and discharge chamber, a sealing member for separating the storage hole and the solution suction and discharge chamber is provided between the fixed block and the injection cavity, a spring is provided in the solution suction and discharge chamber, one end of the spring is fixed to the bottom of the solution suction and discharge chamber, the other end of the spring abuts against the sealing member, one side of the injection and suction joint is provided with an suction and discharge channel connected to the solution suction and discharge chamber, the free end of the electric push rod extends into the storage hole to pressurize the sealing member so that the space size of the solution suction and discharge chamber changes to change the pressure in the solution suction and discharge chamber, one side of the injection and suction joint is plugged into and matched with the filter, and a suction and injection port is provided on the side of the filter away from the injection and suction joint.
[0008] As an improvement, a drainage tube that cooperates with the suction and injection port is provided at one end of the filter away from the injection device. The openings at both ends of the drainage tube are a larger upper and smaller lower structure. The cross-section of the side of the drainage tube that cooperates with the injection bottle is smaller than the cross-section of the side that cooperates with the suction and injection port at the filter.
[0009] As an improvement, the sealing element is made of rubber material.
[0010] As an improvement, the filter includes a shell, the shell has a connecting cavity connected to the suction and injection connector, one side of the shell is detachably connected to a microporous filter component, and one side of the shell is also provided with a makeshift groove that can cooperate with the microporous filter component; when the microporous filter component is inserted into the makeshift groove, the microporous filter component is placed in the connecting cavity and cooperates with the suction and injection connector, and one side of the shell is provided with a connecting port that can be plugged and cooperated with the suction and injection connector.
[0011] As an improvement, the microporous filtration assembly includes a microporous filtration membrane that cooperates with the suction and injection connector, and an upper filter membrane bracket and a lower filter membrane bracket that cooperate with each other. The upper filter membrane bracket and the lower filter membrane bracket are both in the shape of a ring, and a grid is provided in the middle of the ring to support the microporous filtration membrane. The microporous filtration membrane is a single piece, which is placed between the upper filter membrane bracket and the lower filter membrane bracket and matches the position of the grid.
[0012] As an improvement, the filter also includes an insert for installing a microporous filtration component, the insert includes a gripping block protruding from the outside of the shell for human hand to grasp, and a membrane ring located in the connecting cavity, the microporous filtration component is placed in the membrane ring and fixed to the membrane ring by heat pressing, and a connecting block is provided between the membrane ring and the gripping block.
[0013] As an improvement, the electric push rod adopts a servo motor type electric push rod or an electric push rod with an encoding motor.
[0014] Beneficial effects of the present invention: The present invention is different from the existing syringes that use a push injection method. The free end of the electric push rod is changed to push out the seal and cooperate with the spring to change the internal pressure of the solution suction and discharge chamber to achieve the function of suction and discharge of liquid. The standard stroke of the existing electric push rod is between 100-400mm, but its maximum thrust on the seal can reach 6000N, making it have the characteristics of controllable stroke and large thrust. When the injection bottle is constant volume in the pesticide residue detection environment, the external solution is first sucked through the large stroke, and then the stroke of the electric push rod is controlled to gradually and slowly discharge the solution in the solution suction and discharge chamber. The discharged solution is directly introduced into the injection bottle.
[0015] When in use, the free end of the electric push rod is used to push out the seal to reduce the space in the solution suction and discharge chamber and squeeze the spring, then the suction and injection port is extended into the solution to be absorbed, and then the electric push rod is started to retract the free end of the electric push rod, and the solution suction and discharge chamber expands its space size under the action of the spring, forming a negative pressure in the solution suction and discharge chamber to suck the external solution. When the liquid needs to be discharged, the free end of the electric push rod is extended, and the seal is pushed out again, and the spring is compressed, so that the space in the solution suction and discharge chamber becomes smaller and pressurized. This pressurization is conducive to filtering the solution through the filter, so that foreign matter and particles in the injection solution can be filtered, the filtering effect is good and the clogging of the chromatographic column can be avoided. This method can also be used to operate trace amounts of liquid. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic structural diagram of an embodiment of the present invention;
[0017] Figure 2 yes Figure 1 A schematic diagram of the structure of the suction and injection joint, the filter and the drainage tube in a matching state;
[0018] Figure 3 yes Figure 2 Schematic diagram of the structure after the drainage tube is removed;
[0019] Figure 4 yes Figure 3 Schematic diagram of structural explosion;
[0020] Figure 5 yes Figure 4 Schematic diagram of the structure of the mesoporous filtration assembly;
[0021] Figure 6 yes Figure 5 Schematic diagram of the structural explosion.
[0022] Figure numerals: 1. injection device; 2. filter; 3. electric push rod; 4. fixing block; 5. injection cavity; 6. suction and injection joint; 7. storage hole; 8. solution suction and discharge chamber; 9. sealing member; 10. spring; 11. suction and discharge channel; 12. suction and injection port; 13. drainage tube; 14. shell; 15. connecting cavity; 16. microporous filter assembly; 17. connecting port; 18. give way groove; 19. microporous filter membrane; 20. upper filter membrane bracket; 21. lower filter membrane bracket; 22. grid; 23. plug-in; 24. holding block; 25. membrane ring; 26. connecting block. DETAILED DESCRIPTION
[0023] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0024] like Figure 1-Figure 6 As shown, a syringe for trace substance analysis includes an injection device 1 and a filter 2. The injection device 1 includes an electric push rod 3, a fixed block 4 for mounting the electric push rod 3, an injection cavity 5 and an injection and suction joint 6 arranged in sequence from top to bottom. A storage hole 7 for accommodating the electric push rod 3 is arranged on one side of the fixed block 4. A solution suction and discharge chamber 8 is provided in the injection cavity 5. A sealing member 9 for separating the storage hole 7 and the solution suction and discharge chamber 8 is arranged between the fixed block 4 and the injection cavity 5. A spring 10 is arranged in the solution suction and discharge chamber 8. One end of the spring 10 is fixed to the bottom of the solution suction and discharge chamber 8, and the other end is in contact with the sealing member 9. A suction and discharge channel 11 connected to the solution suction and discharge chamber 8 is arranged on one side of the injection and suction joint 6. The free end of the electric push rod 3 extends into the storage hole 7 to press the sealing member 9 so that the space size of the solution suction and discharge chamber 8 changes to change the pressure in the solution suction and discharge chamber 8, thereby completing the suction and discharge action. The spring 10 helps the seal 9 to return to the initial state without the force of the electric push rod 3. One side of the suction and injection connector 6 is plugged with the filter 2, and the side of the filter 2 away from the suction and injection connector 6 is provided with a suction and injection port 12.
[0025] The present invention is different from the existing syringes that use push injection. The free end of the electric push rod 3 is changed to push out the seal 9 and cooperate with the spring 10 to change the internal pressure of the solution suction and discharge chamber 8 to achieve the function of suction and discharge of liquid. The standard stroke of the existing electric push rod 3 is between 100-400mm, but its maximum thrust on the seal 9 can reach 6000N, which makes it have the characteristics of controllable stroke and large thrust. When the injection bottle is constant volume in the pesticide residue detection environment, the external solution is first sucked through the large stroke, and then the stroke of the electric push rod 3 is controlled to gradually and slowly discharge the solution in the solution suction and discharge chamber 8. The discharged solution is directly introduced into the inner liner of the injection bottle.
[0026] When in use, the free end of the electric push rod 3 is used to push out the seal 9 so that the space in the solution suction and discharge chamber 8 becomes smaller and the spring 10 is squeezed, and then the suction and injection port 12 is extended into the solution to be absorbed, and then the electric push rod 3 is started so that the free end of the electric push rod 3 retracts, and the solution suction and discharge chamber 8 expands its space size under the action of the spring 10, forming a negative pressure in the solution suction and discharge chamber 8 to suck the external solution. When it is necessary to discharge the liquid, the free end of the electric push rod 3 is extended, and the seal 9 is pushed out again, and the spring 10 is compressed, so that the space in the solution suction and discharge chamber 8 becomes smaller and the pressure is increased. This pressure increase is conducive to the filtration of the solution through the filter 2, so that foreign matter and particles in the injection solution can be filtered, and the filtering effect is good and the clogging of the chromatographic column can be avoided. This method can also be used to operate trace amounts of liquid.
[0027] Furthermore, a drainage tube 13 matching with the suction and injection port 12 is provided at one end of the filter 2 away from the injection device 1, and the drainage tube 13 can drain the sample solution to be detected into the inner liner tube in the injection bottle for constant volume. The drainage tube 13 has two openings at both ends with a large upper and small lower structure, and the cross section of one side matching with the inner liner tube in the injection bottle is smaller than the cross section of one side matching with the suction and injection port 12 at the filter 2, so that when the solution filtered and discharged by the filter 2 passes through the drainage tube 13, it can be briefly accumulated in the drainage tube 13 (because the liquid inlet speed of the drainage tube 13 is greater than the liquid outlet speed), which can facilitate the user to accurately constant the volume of the injection bottle, give the user a chance to make mistakes, and extend the reaction time of the error-tolerant rescue.
[0028] Furthermore, the sealing member 9 is made of rubber material, so that the raw material of the sealing member 9 is clean, easy to obtain and easy to process.
[0029] Furthermore, the filter 2 includes a housing 14, the housing 14 has a connecting cavity 15 that can be connected to the suction and injection connector 6, and a microporous filter component 16 is detachably connected to one side of the housing 14. A clearance groove 18 that can cooperate with the microporous filter component 16 is also provided on one side of the housing 14. When the microporous filter component 16 is inserted into the clearance groove 18, the microporous filter component 16 is placed in the connecting cavity 15 and cooperates with the suction and injection connector 6. A connecting port 17 that can be plugged and matched with the suction and injection port 12 is provided on one side of the housing 14. By detachably mounting the housing 14 at the suction and injection connector 6 at one end of the injection device 1, and detachably mounting the microporous filter component 16 on the housing 14, the user can replace the microporous filter component 16 of the corresponding pore size according to actual needs to meet the microporous filtration needs of different types of chromatographic columns. At the same time, two microporous filter components 16 can be used in the two links of liquid aspiration and liquid injection respectively to perform secondary filtration on the solution to be introduced into the injection bottle, thereby achieving high-precision removal of tiny particles in the solution and avoiding clogging of the chromatographic column. Therefore, after a single use, there is no need to discard the entire filter 2, and only the microporous filter component 16 needs to be replaced, so that it can be reused multiple times.
[0030] Furthermore, the microporous filter assembly 16 includes a microporous filter membrane 19 matched with the suction and injection connector 6, and an upper filter membrane support 20 and a lower filter membrane support 21 that match each other. The upper filter membrane support 20 and the lower filter membrane support 21 are both in the shape of a ring, and a grid 22 is provided in the middle of the ring to set off the microporous filter membrane 19. The microporous filter membrane 19 is a single piece, which is placed between the upper filter membrane support 20 and the lower filter membrane support 21 and matches the position of the grid 22. When the injection device 1 injects liquid, the solvent in the injection device 1 can be microporously filtered through the filter 2 under the action of pressure.
[0031] Furthermore, the filter 2 also includes an insert 23 for installing the microporous filter assembly 16. The insert 23 includes a gripping block 24 protruding from the outside of the housing 14 for human hands to grasp, and a membrane ring 25 located in the communication cavity 15. The microporous filter assembly 16 is placed in the membrane ring 25 and fixed to the membrane ring 25 by heat pressing. A connecting block 26 is provided between the membrane ring 25 and the gripping block 24. When the microporous filter assembly 16 needs to be replaced or installed, it is only necessary to grasp the gripping block 24 by human hands to control the installation and removal of the microporous filter assembly 16.
[0032] Furthermore, the electric push rod 3 can be a servo motor type electric push rod or an electric push rod with an encoding motor, which can make the free end extend and retract a fixed distance to better push out the sealing member 9, thereby adjusting the pressure in the solution suction and discharge chamber 8. This is a prior art and will not be described in detail here.
[0033] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.
Claims
1. A syringe for trace substance analysis, comprising an injection device (1) and a filter (2), characterized in that: The injection device (1) comprises an electric push rod (3), a fixed block (4) for mounting the electric push rod (3), an injection cavity (5) and an injection and suction joint (6) which are arranged in sequence from top to bottom. A storage hole (7) for accommodating the electric push rod (3) is arranged on one side of the fixed block (4). A solution suction and discharge chamber (8) is arranged in the injection cavity (5). A sealing member (9) for separating the storage hole (7) and the solution suction and discharge chamber (8) is arranged between the fixed block (4) and the injection cavity (5). A spring (10) is arranged in the solution suction and discharge chamber (8). One end of the spring (10) is fixed to the bottom of the solution suction and discharge chamber (8), and the other end of the spring (10) is in contact with the sealing member (9). A suction and discharge channel (11) communicating with the solution suction and discharge chamber (8) is arranged on one side of the injection and suction joint (6). The free end of the electric push rod (3) extends into the storage hole (7) to apply pressure to the sealing member (9) so that the spatial size of the solution suction and discharge chamber (8) changes to change the pressure in the solution suction and discharge chamber (8), and the spring (10) assists the sealing member (9) to return to the initial state when there is no force applied by the electric push rod (3); one side of the suction and injection joint (6) is plugged into and matched with the filter (2), and a suction and injection port (12) is provided on the side of the filter (2) away from the suction and injection joint (6), and a drainage tube (13) matching with the suction and injection port (12) is provided on the end of the filter (2) away from the injection device (1), and the drainage tube (13) has two ends with a larger upper and smaller lower structure, and the cross section of the side of the drainage tube (13) matching with the inner lining tube is smaller than the cross section of the side matching with the suction and injection port (12) at the filter (2); The filter (2) comprises a shell (14), wherein the shell (14) is provided with a connecting cavity (15) which can be communicated with the suction and injection connector (6), and a microporous filter component (16) is detachably connected to one side of the shell (14), and a clearance groove (18) which can cooperate with the microporous filter component (16) is also provided on one side of the shell (14); when the microporous filter component (16) is inserted into the clearance groove (18), the microporous filter component (16) is placed in the connecting cavity (15) and cooperates with the suction and injection connector (6), and a connecting port (17) which can be plugged and matched with the suction and injection connector (6) is provided on one side of the shell (14); two microporous filter components (16) can be used respectively in the two links of suction and injection to perform secondary filtration on the solution to be introduced into the injection bottle.
2. A syringe for trace substance analysis according to claim 1, characterized in that: The sealing member (9) is made of rubber material.
3. A syringe for trace substance analysis according to claim 1, characterized in that: The microporous filter assembly (16) comprises a microporous filter membrane (19) matched with the suction and injection joint (6), and an upper filter membrane support (20) and a lower filter membrane support (21) matched with each other. The upper filter membrane support (20) and the lower filter membrane support (21) are both in the shape of a ring, and a grid (22) for supporting the microporous filter membrane (19) is provided in the middle of the ring. The microporous filter membrane (19) is a single piece, which is placed between the upper filter membrane support (20) and the lower filter membrane support (21) and matches the position of the grid (22).
4. A syringe for trace substance analysis according to claim 3, characterized in that: The filter (2) further comprises an insert (23) for mounting a microporous filter assembly (16), the insert (23) comprising a gripping block (24) protruding from the outside of the housing (14) for grasping by a human hand, and a membrane ring (25) located in the connecting cavity (15), the microporous filter assembly (16) being placed in the membrane ring (25) and being fixed to the membrane ring (25) by heat pressing, and a connecting block (26) being provided between the membrane ring (25) and the gripping block (24).
5. The syringe for trace substance analysis according to claim 1, characterized in that: The electric push rod (3) is a servo motor type electric push rod or an electric push rod with an encoding motor.