A device and method for water sample container wall residue elution coupled with solid phase extraction

Abstract

The application discloses a water sample container wall residual elution and solid phase extraction combined device and method, and belongs to the field of environmental monitoring water sample pretreatment. The water sample container wall residual elution and solid phase extraction combined device comprises a carrier table, a vortex oscillator is fixedly arranged on the carrier table, a connecting head is connected to a vibration end of the vortex oscillator, a clamping disc is inserted on the connecting head, a plurality of water sample containers are clamped on the clamping disc, a vertical plate is fixedly connected to the carrier table, and a first electric telescopic rod is connected to the vertical plate. Methanol storage tanks, liquid outlet pipes and the vortex oscillator are synchronously operated, methanol elution solvents are added to the water sample containers at the same time, the clamping disc and the water sample containers are driven by the vortex oscillator to synchronously perform eccentric circular oscillation, dynamic turbulent flow and vortex disturbance are synchronously formed in the process that the elution solvents flow along the bottle wall, and long-chain perfluorinated compounds that are stubbornly adsorbed on the inner wall of the bottle can be instantaneously flushed and desorbed.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring water sample pretreatment technology, and in particular to a device and method for combining water sample container wall residue elution and solid phase extraction. Background Technology

[0002] Perfluorinated compounds (PFASs) are a class of persistent organic pollutants with strong chemical stability and bioaccumulation, and have been included in the priority control lists for environmental water bodies both domestically and internationally. For the detection of trace PFASs in environmental water samples such as surface water, wastewater, and groundwater, solid phase extraction (SPE) is currently the mainstream sample pretreatment technique, which can enrich and purify the target analytes, meeting the requirements for on-machine detection by instruments such as chromatography and mass spectrometry. In actual detection, it has been found that long-chain PFASs have strong interfacial adsorption characteristics and are easily adsorbed on the inner wall of the water sample container. If only the main body of the water sample is subjected to solid phase extraction, the target analytes will be lost due to adsorption on the bottle wall, resulting in low final detection results, unsatisfactory recovery rates, and an inability to accurately reflect the true concentration of PFASs in the water body.

[0003] To compensate for the loss of target substances due to adsorption on the bottle wall, the industry has developed a standard bottle wall elution process: after the water sample is loaded, methanol is added as an elution solvent to the empty water sample bottle, and the perfluorinated compounds adsorbed on the bottle wall are desorbed by shaking. The bottle wall cleaning solution is then passed into a solid phase extraction column for secondary enrichment, thereby improving the overall detection recovery rate.

[0004] Currently, this elution process is mainly completed step-by-step by manual labor in conjunction with independent benchtop equipment. The specific operation process is as follows: In the liquid addition step, the experimenter uses a pipette to add methanol elution solvent quantitatively to each large-capacity water sample bottle, with the solvent dripping directly to the bottom of the bottle; in the transfer step, the water sample bottles with added solvent are manually moved to the benchtop vortex shaker; in the shaking step, the vortex shaker is started, and the platform is driven by an eccentric motor to perform a circular vortex motion, causing the sample bottle to rotate and shake. The turbulence formed by the liquid inside the bottle washes the bottle wall, achieving the desorption of the adsorbed target analyte; in the subsequent transfer step, after the shaking reaches the set time, the sample bottle is manually removed, completing the transfer of the washing solution to the collection bottle.

[0005] In the aforementioned prior art, the liquid addition process and the vortex oscillation process are performed sequentially. After the methanol elution solvent is added, it is placed at the bottom of the bottle, and the flushing effect is not generated synchronously when the solvent comes into contact with the bottle wall. At the same time, the vortex time and oscillation intensity of different sample bottles depend on manual control, which makes it difficult to maintain consistency. In addition, the above process requires manual liquid addition, handling and loading / unloading operations for each bottle, which is labor-intensive and time-consuming when processing batches of samples. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of high manual operation in the prior art, the inability of manual vortexing to achieve the same vortexing time and force for each sample bottle, which affects the repeatability of target analyte recovery rate, and the low efficiency of batch sample processing.

[0007] A device for combined elution of water sample container wall residue and solid-phase extraction includes a stage, on which a vortex oscillator is fixedly mounted. The vibrating end of the vortex oscillator is connected to a connector, and a clamping plate is inserted into the connector. Multiple water sample containers are clamped on the clamping plate. A vertical plate is fixedly connected to the stage, and a first electric telescopic rod is connected to the vertical plate. The driving end of the first electric telescopic rod is connected to a lifting ring, and multiple methanol storage tanks are fixedly connected to the lifting ring. The lower end of each methanol storage tank is connected to an outlet pipe, which is located directly above the water sample containers. A metering pump is connected to the outlet pipe. Multiple solid-phase extraction columns are placed on the platform, and an operating table is also fixed on the platform. The operating table is used to place a clamping plate, on which an empty water sample container is placed.

[0008] To facilitate the connection of the clamping disc, preferably, a plug is fixedly connected to the bottom side of the clamping disc. The plug is used to insert into the connector. The connector has a slot corresponding to the plug, and a locking rubber pad is provided inside the slot.

[0009] To facilitate the movement of the clamping disc, preferably, a movable mechanical gripper is also included. A movable column is fixedly connected to the clamping disc, and a locking block is slidably connected above the movable column. The movable mechanical gripper is locked at the upper end of the movable column, and a slot corresponding to the locking block is opened on the movable mechanical gripper.

[0010] Furthermore, a lifting plate is provided on the moving column, and the lower end of the lifting plate is fixedly connected to the clamping plate through a return spring. Two clamping blocks are symmetrically arranged, and a return tension spring is connected between the two clamping blocks. A first tilting drive plate is fixedly connected to the lifting plate, and the side wall of the clamping block is provided with a first tilting surface corresponding to the first tilting drive plate. A second electric telescopic rod is fixedly connected to the upright plate. The second electric telescopic rod is located above the lifting plate. When the clamping plate is moved above the vortex oscillator and engaged with the connector by the moving mechanical gripper, the second electric telescopic rod moves downward. The drive end pushes the lifting plate downward. At this time, the first inclined drive plate disengages from the first inclined surface. Under the action of the reset spring, the two clamping blocks move towards each other, thereby disengaging from the slot of the moving mechanical gripper and completing the movement of the clamping plate and the water sample container.

[0011] To facilitate locking the lifting plate, a locking column is further connected to the moving column via a locking spring, and an inclined plate is fixedly connected to the lifting plate. The locking column has a slope surface corresponding to the inclined plate. When the moving mechanical gripper is clamped on the moving column, by pulling the locking column, the lifting plate moves up under the action of the return spring, pushing the clamping block into the slot, so that the moving mechanical gripper can clamp the moving column and the clamping plate.

[0012] To better clamp the sample container, the clamping plate is further provided with clamping holes in which clamping plates are connected by clamping springs.

[0013] Furthermore, a clamping rod is slidably connected to the clamping plate, and the clamping rod abuts against the clamping piece. A second inclined drive plate is fixedly connected to the lower end of the lifting plate. A second inclined surface corresponding to the second inclined drive plate is provided on the clamping rod. When the lifting plate moves down, the clamping rod is pushed against the clamping piece by the second inclined drive plate and the second inclined surface, so as to better fix the sample container.

[0014] Preferably, a fixed support is fixedly connected to the platform, the support is used to place the solid phase extraction column, and a collection bottle is placed under the support, the collection bottle being located below the solid phase extraction column.

[0015] A method for combining elution of water sample container wall residues with solid-phase extraction, the specific steps of which are as follows: S1, Solid-phase extraction column activation S2, Initial sample loading The original water sample in the water sample container is passed into the activated solid phase extraction column using a suction pump, so that the target substances in the water sample are adsorbed by the solid phase extraction column, and an empty water sample container is obtained. S3, Rinse to remove impurities Eluent is introduced into the solid phase extraction column to remove interfering impurities from the column. S4, Air-driven drying The solid phase extraction column was subjected to air-driven and blow-drying treatment to remove residual moisture and eluent from the solid phase extraction column. S5, Stepwise Gradient Elution First, methanol is introduced into the solid-phase extraction column for the first round of elution; Then ammonia and methanol are introduced again to complete the second round of gradient elution; S6, Final Air Thrust The solid-phase extraction column is then purged again to collect all the eluent, completing the entire pretreatment process. S7. Sample vial wall cleaning Place the empty water sample container obtained in S2 on the clamping plate, and use the moving mechanical gripper to move the column to transfer the clamping plate to the vibration end of the vortex oscillator and position it. The first electric telescopic rod drives the lifting ring to descend, so that the outlet of the liquid outlet tube extends into the mouth of the water sample container, and then the quantitative pump and the vortex shaker are started simultaneously. A metering pump dispenses methanol eluent from the methanol storage tank into each water sample container via the outlet pipe. At the same time, a vortex oscillator drives the clamping plate and the water sample container to perform eccentric circular oscillation, so that the methanol eluent forms dynamic turbulence and vortex disturbance as it flows along the inner wall of the water sample container, which washes away and desorbs the target substances adsorbed on the inner wall of the water sample container. After the metering pump stops adding liquid, the vortex oscillator continues to run for a preset time to obtain bottle wall cleaning solution; The first electric telescopic rod drives the lifting ring to rise to the avoidance position; S8, Cleaning fluid collection The clamping plate is transferred from the vibrating end of the vortex oscillator to the operating table by a moving mechanical gripper, and the bottle wall cleaning solution in the water sample container is introduced into the solid phase extraction column and collected into the collection bottle.

[0016] Application of a combined method of elution of water sample container wall residues and solid phase extraction in the pretreatment of water samples for the detection of perfluorinated compounds.

[0017] Compared with existing technologies, it has the following beneficial effects: 1. The methanol storage tank, outlet pipe, and vortex oscillator operate synchronously. While adding methanol as the elution solvent to the water sample container, the vortex oscillator drives the clamping plate and the water sample container to perform eccentric circular oscillations simultaneously. This causes dynamic turbulence and vortex disturbances to be generated simultaneously as the elution solvent flows along the bottle wall, which can immediately flush away stubborn long-chain perfluorinated compounds adsorbed on the inner wall of the sample bottle. By controlling the vortex time and power, the elution process is the same for each sample bottle, ensuring an overall improvement in the recovery rate of long-chain perfluorinated compounds.

[0018] 2. Multiple water sample containers can be clamped and fixed simultaneously by the clamping plate, and the metering pump enables multi-channel synchronous metering of liquid, so that the bottle wall elution operation of multiple sets of samples can be completed in a single batch. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the combined device; Figure 2 yes Figure 1 Schematic diagram of the structure at point A; Figure 3 yes Figure 1 Schematic diagram of the structure at point B; Figure 4 This is a cross-sectional structural diagram of the combined device; Figure 5 yes Figure 4 Schematic diagram of the structure at point C; Figure 6 yes Figure 5 Schematic diagram of the structure at point D; Figure 7 yes Figure 5 A schematic diagram of the structure at point E in the middle.

[0020] In the diagram: 1. Stage; 2. Vortex oscillator; 3. Operating table; 4. Fixed bracket; 5. Clamping plate; 6. Vertical plate; 7. First electric telescopic rod; 8. Second electric telescopic rod; 9. Water sample container; 10. Moving column; 11. Moving mechanical gripper; 12. Lifting plate; 13. Lifting ring; 14. Methanol storage tank; 15. Discharge pipe; 16. Metering pump; 17. Clamping block; 18. Locking column; 19. Support rod; 20. Clamping spring; 1. Clamping plate; 22. Return spring; 201. Connector; 202. Insert block; 401. Solid phase extraction column; 402. Collection bottle; 501. Clamping hole; 1101. Slot; 1701. First inclined surface; 1702. First inclined drive plate; 1703. Return tension spring; 1801. Sloping surface; 1802. Inclined clamping plate; 1803. Locking tension spring; 1901. Second inclined surface; 1902. Second inclined drive plate. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Example 1: Refer to Figure 1-3 A device for combined elution of water sample container wall residue and solid phase extraction includes a stage 1, a vortex oscillator 2 fixedly mounted on the stage 1, a connector 201 connected to the vibrating end of the vortex oscillator 2, a clamping plate 5 inserted into the connector 201, a plurality of water sample containers 9 clamped on the clamping plate 5, a vertical plate 6 fixedly connected to the stage 1, a first electric telescopic rod 7 connected to the vertical plate 6, a lifting ring 13 connected to the driving end of the first electric telescopic rod 7, a plurality of methanol storage tanks 14 fixedly connected to the lifting ring 13, an outlet pipe 15 connected to the lower end of the methanol storage tanks 14, the outlet pipe 15 being located above the water sample containers 9, and a metering pump 16 connected to the outlet pipe 15. A fixed support 4 is fixedly provided on the stage 1, and multiple solid phase extraction columns 401 are placed on the fixed support 4. An operating table 3 is also fixedly provided on the stage 1. The operating table 3 is used to place the clamping plate 5. The empty bottle of the water sample container 9 is placed on the clamping plate 5 on the operating table.

[0023] Reference Figure 1 A fixed support 4 is fixedly connected to the stage 1. The support 4 is used to place the solid phase extraction column 401. A collection bottle 402 is placed under the support 4. The collection bottle 402 is placed directly below the solid phase extraction column 401 and is used to collect the eluent.

[0024] In specific implementation, the number of solid phase extraction columns 401 can be designed to be 6, but is not limited to 6. In this embodiment, the number of solid phase extraction columns 401 is 6, and the water sample container 9 that can be gripped in the clamping disk 5 can also grip 6 at a time, which is consistent with the number of solid phase extraction columns 401; thus realizing continuous operation and processing 6 samples per batch.

[0025] It should also be noted that in order to improve work efficiency, six vortex oscillators 2 can be set on the stage 1 to perform multiple batch operations simultaneously.

[0026] Reference Figure 4 and Figure 5 A plug 202 is fixedly connected to the bottom side of the clamping disc 5. The plug 202 is used to insert into the connector 201. The connector 201 has a slot corresponding to the plug 202, and the slot has a locking rubber pad inside. The clamping disc 5 is engaged with the slot of the connector 201 through the plug 202 at the bottom, which can be quickly disassembled and replaced. The locking rubber pad inside the slot can fill the assembly gap between the plug 202 and the slot, which increases the friction of the contact surface and ensures that the clamping disc 5 will not loosen or shift during vortex oscillation. It can also buffer some of the vibration and impact.

[0027] The vortex oscillator 2 is fixedly installed on the platform 1; the clamping plate 5 is connected to the vibrating end of the vortex oscillator 2 through the connector 201. The clamping plate 5 can clamp multiple water sample containers 9 at the same time to realize batch vortex elution of multiple samples; the upright plate 6 is vertically fixed on one side of the platform 1, and the first electric telescopic rod 7 is installed on the upper part of the upright plate 6 in the vertical direction. Its driving end drives the lifting ring 13 to realize vertical lifting and lowering movement, thereby driving the methanol storage tank 14 and the outlet pipe 15 to lift and lower synchronously: when adding liquid, the lifting ring 13 descends, so that the outlet pipe 15 is close to but does not contact the mouth of the water sample container 9, ensuring accurate solvent addition.

[0028] During vortex oscillation, the lifting ring 13 rises to avoid obstruction. The metering pump 16 is installed on the outlet pipe 15 and can control the volume and flow rate of methanol elution solvent, thereby achieving automated metering.

[0029] Solid phase extraction column 401 is arranged on stage 1 to complete the adsorption and enrichment of target substances in water sample; operating table 3 serves as an auxiliary station for loading and unloading water sample container 9 and temporarily placing clamping plate 5 to realize loading, vortex elution and secondary collection.

[0030] The entire device integrates the vortex elution unit and the solid phase extraction unit on the same platform 1, eliminating the step of sample transfer across workstations and realizing the combined operation of bottle wall elution and solid phase extraction.

[0031] Example 2: Refer to Figure 5 and Figure 6 A device for eluting water sample container wall residue and combining solid phase extraction is basically the same as that in Example 1, except that it also includes a movable mechanical gripper 11, a movable column 10 is fixedly connected to the clamping plate 5, a locking block 17 is slidably connected above the movable column 10, the movable mechanical gripper 11 is locked at the upper end of the movable column 10, and a locking groove 1101 corresponding to the locking block 17 is opened on the movable mechanical gripper 11.

[0032] When the clamping plate 5 is transferred to another station, the mobile mechanical gripper 11 moves down and fits onto the upper end of the mobile column 10. The locking block 17 on the mobile column 10 slides outward and locks into the slot 1101 of the mobile mechanical gripper 11, thus achieving a locking connection between the mobile mechanical gripper 11 and the clamping plate 5. The mobile mechanical gripper 11 can drive the clamping plate 5 to transfer between the vortex oscillator 2, the operating table 3, and the solid phase extraction station, thereby improving the automation level of the process and reducing the intensity of manual labor.

[0033] Reference Figure 6 A lifting plate 12 is installed on the moving column 10. The lower end of the lifting plate 12 is fixedly connected to the clamping plate 5 through a return spring 22. Two symmetrically arranged locking blocks 17 are connected between the two locking blocks 17. A first tilting drive plate 1702 is fixedly connected on the lifting plate 12. The side wall of the locking block 17 is provided with a first tilting surface 1701 corresponding to the first tilting drive plate 1702. A second electric telescopic rod 8 is fixedly connected to the upright plate 6. The second electric telescopic rod 8 is located above the lifting plate 12. When the clamping plate 5 is moved above the vortex oscillator 2 and engaged in the connector 201 by the moving mechanical gripper 11, the second electric telescopic rod 8 moves downward. The drive end pushes the lifting plate 12 downward. At this time, the first inclined drive plate 1702 disengages from the first inclined surface 1701. Under the action of the reset spring 1703, the two clamping blocks 17 move towards each other, thereby disengaging from the slot 1101 of the moving mechanical gripper 11 and completing the movement of the clamping plate 5 and the water sample container 9.

[0034] Automatic unlocking and separation of the clamping disc 5 and the mobile mechanical gripper 11 are achieved: Under normal conditions, the reset spring 22 pushes the lifting plate 12 upward, so that the first inclined drive plate 1702 abuts against the first inclined surface 1701 of the locking block 17, and the two locking blocks 17 are pushed away from each other and extended through the inclined surface transmission, maintaining the locking state.

[0035] After the clamping plate 5 is moved to the connector 201 of the vortex oscillator 2 by the moving mechanical gripper 11, the drive end of the second electric telescopic rod 8 extends downward, presses the lifting plate 12 to move downward against the elastic force of the reset spring 22, and the first tilting drive plate 1702 moves down and separates from the first tilting surface 1701. The two locking blocks 17 retract towards each other under the pulling force of the reset spring 1703 and disengage from the locking slot 1101 of the moving mechanical gripper 11, thus completing the automatic unlocking.

[0036] Reference Figure 6 A locking column 18 is connected to the moving column 10 via a locking spring 1803. An inclined plate 1802 is fixedly connected to the lifting plate 12. The locking column 18 has a slope surface 1801 corresponding to the inclined plate 1802. When the moving mechanical gripper 11 is clamped on the moving column 10, by pulling the locking column 18, the lifting plate 12 moves upward under the action of the return spring 22, pushing the clamping block 17 into the slot 1101, so that the moving mechanical gripper 11 clamps the moving column 10 and the clamping plate 5. Automatic locking between the mobile mechanical gripper 11 and the clamping plate 5 is achieved: when the mobile mechanical gripper 11 is sleeved on the upper end of the moving column 10, the locking column 18 is pulled outward, and the inclined surface 1801 of the locking column 18 slides along the inclined plate 1802, releasing the position limit of the lifting plate 12; at this time, the return spring 22 rebounds and pushes the lifting plate 12 to move upward, and pushes the locking block 17 outward through the first inclined drive plate 1702 and locks it into the slot 1101, completing the automatic locking; the locking tension spring 1803 can pull the locking column 18 to reset when the locking column 18 is not subjected to external force, and cooperates with the inclined plate 1802 to lock the position of the lifting plate 12.

[0037] In practical implementation, to further reduce manpower, a robotic arm can be installed on the platform 1. The moving end of the robotic arm is connected to the mobile mechanical gripper 11 to realize the displacement of the clamping plate 5. The multi-axis robotic arm drives the mobile mechanical gripper 11 to automatically complete the entire process of gripping, transferring and placing the clamping plate 5, thereby improving the automation level of batch sample processing.

[0038] Reference Figure 5 The clamping plate 5 has a clamping hole 501 in which a clamping piece 21 is connected by a clamping spring 20. When the water sample container 9 is placed in the clamping hole 501, the elastic force of the clamping spring 20 pushes the clamping piece 21 against the outer wall of the water sample container 9, thereby achieving elastic clamping and fixing of the water sample container 9.

[0039] Reference Figure 5 and Figure 7 A clamping rod 19 is slidably connected to the clamping plate 5, and the clamping rod 19 abuts against the clamping piece 21. A second tilting drive plate 1902 is fixedly connected to the lower end of the lifting plate 12. A second tilting surface 1901 corresponding to the second tilting drive plate 1902 is opened on the clamping rod 19. When the lifting plate 12 moves down, the clamping rod 19 is pushed against the clamping piece 21 by the second tilting drive plate 1902 and the second tilting surface 1901 to better fix the sample container 9.

[0040] Before the vortex operation, the water sample container 9 is further secured: When the lifting plate 12 is pushed down by the second electric telescopic rod 8, the second inclined drive plate 1702 moves down accordingly. Through the inclined surface transmission of the second inclined surface 1901, the clamping rod 19 slides radially toward the center of the clamping hole 501, further pushing the clamping plate 21, increasing the clamping force of the clamping plate 21 on the water sample container 9, and preventing the water sample container 9 from slipping, shaking or even falling out during the high-speed vortex operation.

[0041] A method for combining elution of water sample container wall residues with solid-phase extraction, the specific steps of which are as follows: S1, Solid phase extraction column 401 activation 5 mL of 0.5% ammonia-methanol solution, 7 mL of methanol, and 10 mL of pure water were sequentially introduced at a flow rate of 3 mL / min to activate the solid-phase extraction column 401, ensuring that the adsorption sites of the packing material were fully wetted and adsorption performance was guaranteed. S2, Initial sample loading Using a suction pump, the original water sample in the water sample container 9 is passed into the activated solid phase extraction column 401 at a flow rate of 10 mL / min. The perfluorinated compounds in the water sample are adsorbed by the solid phase extraction column 401. After the sample loading is completed, an empty water sample container 9 is obtained. S3, Rinse to remove impurities 10 mL of 0.025 mol / L ammonium acetate was introduced into the solid phase extraction column 401 at a flow rate of 3 mL / min to wash the solid phase extraction column 401 and remove interfering impurities; S4, Air-driven drying The solid phase extraction column 401 is subjected to air-driven and blow-drying treatment to remove residual moisture and eluent inside the solid phase extraction column 401. S5, Stepwise Gradient Elution First, 5 mL of methanol was introduced into the solid phase extraction column 401 at a flow rate of 1 mL / min for the first round of elution. Then, another 8 mL of 0.5% ammonia-methanol solution was introduced at a flow rate of 1 mL / min to complete the second round of gradient elution. S6, Final Air Thrust The solid-phase extraction column 401 was then purged again to collect all the eluent, completing the entire pretreatment process.

[0042] S7. Sample vial wall cleaning The empty water sample container 9 after loading is placed on the clamping plate 5, and the clamping plate 5 is clamped on the vortex oscillator 2 by the moving mechanical gripper 11 and the moving column 10. The clamping plate 5 is connected to the connector 201 at the vibrating end of the vortex oscillator 2. Methanol eluent is added to the multiple empty water sample containers 9 on the clamping plate 5 through multiple methanol storage tanks 14 and outlet pipes 15. The metering pump 16 adds the methanol eluent in a metered manner. At the same time, the vortex oscillator 2 drives the multiple empty water sample containers 9 to continuously vortex. The methanol eluent is added to the bottle wall of the water sample container 9. With the help of dynamic turbulent scouring and vortex disturbance, the perfluorinated compounds adsorbed on the inner wall of the bottle are desorbed to obtain the bottle wall cleaning solution. S8, Cleaning fluid collection The water sample container 9 and clamping plate 5, which have been cleaned in step S7 and have bottle wall cleaning solution, are moved to the operating table 3 by the moving mechanical gripper 11. Then, the bottle wall cleaning solution in the water sample container 9 is extracted by the suction pump and introduced into the solid phase extraction column 401. The solution is then introduced into the solid phase extraction column 401 again at a flow rate of 10 mL / min. The cleaning solution is collected in the collection bottle 402. Application of a combined method of elution of water sample container wall residues and solid phase extraction in the pretreatment of water samples for the detection of perfluorinated compounds.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for combined elution of water sample container wall residue and solid-phase extraction, comprising a stage (1), wherein a vortex oscillator (2) is fixedly mounted on the stage (1), and a connector (201) is connected to the vibrating end of the vortex oscillator (2), characterized in that, A clamping plate (5) is inserted into the connector (201), and multiple water sample containers (9) are clamped on the clamping plate (5). A vertical plate (6) is fixedly connected to the platform (1), and a first electric telescopic rod (7) is connected to the vertical plate (6). A lifting ring (13) is connected to the driving end of the first electric telescopic rod (7). Multiple methanol storage tanks (14) are fixedly connected to the lifting ring (13). An outlet pipe (15) is connected to the lower end of the methanol storage tank (14). The outlet pipe (15) is located above the water sample container (9), and the outlet of the outlet pipe (15) can extend into the bottle mouth of the water sample container (9). A metering pump (16) is connected to the outlet pipe (15). The stage (1) is fixedly connected to the fixed support (4), and multiple solid phase extraction columns (401) are placed on the fixed support (4). The stage (1) is also fixedly provided with an operating table (3), which is used to place a clamping plate (5). The empty bottle of the water sample container (9) is placed on the clamping plate (5) on the operating plate.

2. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 1, characterized in that, The clamping plate (5) is fixedly connected to the bottom side of the insert (202), the insert (202) is used to insert into the connector (201), and the connector (201) has a slot corresponding to the insert (202).

3. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 1, characterized in that, It also includes a mobile mechanical gripper (11), on which a mobile column (10) is fixedly connected, and a locking block (17) is slidably connected above the mobile column (10). The mobile mechanical gripper (11) is locked at the upper end of the mobile column (10), and a slot (1101) corresponding to the locking block (17) is opened on the mobile mechanical gripper (11).

4. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 3, characterized in that, A lifting plate (12) is installed on the movable column (10). The lower end of the lifting plate (12) is fixedly connected to the clamping plate (5) by a return spring (22). There are two symmetrically arranged clamping blocks (17). A return tension spring (1703) is connected between the two clamping blocks (17). A first tilting drive plate (1702) is fixedly connected on the lifting plate (12). The side wall of the clamping block (17) is provided with a first tilting surface (1701) corresponding to the first tilting drive plate (1702). A second electric telescopic rod (8) is fixedly connected to the upright plate (6), and the second electric telescopic rod (8) is located above the lifting plate (12).

5. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 4, characterized in that, The movable column (10) is connected to a locking column (18) by a locking spring (1803), and the lifting plate (12) is fixedly connected to an inclined plate (1802). The locking column (18) has a slope surface (1801) corresponding to the inclined plate (1802).

6. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 4, characterized in that, The clamping plate (5) has a clamping hole (501), and a clamping piece (21) is connected to the clamping hole (501) by a clamping spring (20).

7. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 6, characterized in that, A clamping rod (19) is slidably connected to the clamping plate (5). The clamping rod (19) abuts against the clamping piece (21). A second inclined drive plate (1902) is fixedly connected to the lower end of the lifting plate (12). A second inclined surface (1901) corresponding to the second inclined drive plate (1902) is opened on the clamping rod (19).

8. The apparatus for combined elution of water sample container wall residue and solid-phase extraction according to claim 1, characterized in that, A fixed support (4) is fixedly connected to the stage (1). The fixed support (4) is used to place the solid phase extraction column (401). A collection bottle (402) is placed under the fixed support (4). The collection bottle (402) is located below the solid phase extraction column (401).

9. A method for combining elution of water sample container wall residue with solid-phase extraction, using the combined apparatus described in claim 1, characterized in that, The specific steps are as follows: S1, Activation of solid phase extraction column (401) S2, Initial sample loading The original water sample in the water sample container (9) is passed into the activated solid phase extraction column (401) by a suction pump so that the target substances in the water sample are adsorbed by the solid phase extraction column, and an empty water sample container (9) is obtained. S3, Rinse to remove impurities Eluent is introduced into the solid phase extraction column (401) to wash away interfering impurities on the solid phase extraction column (401); S4, Air-driven drying The solid phase extraction column (401) was subjected to air-driven and blow-drying treatment to remove residual water and eluent inside the solid phase extraction column (401); S5, Stepwise Gradient Elution First, methanol is introduced into the solid phase extraction column (401) for the first round of elution; Then ammonia and methanol are introduced again to complete the second round of gradient elution; S6, Final Air Thrust The solid phase extraction column (401) was then purged again to collect all the eluent, thus completing the entire pretreatment process. S7. Sample vial wall cleaning Place the empty water sample container (9) obtained in S2 on the clamping plate (5), and use the moving mechanical gripper (11) to clamp the moving column (10) to transfer the clamping plate (5) to the vibration end of the vortex oscillator (2) and position it. The first electric telescopic rod (7) drives the lifting ring (13) to descend, so that the outlet of the liquid outlet pipe (15) extends into the mouth of the water sample container (9), and then the quantitative pump (16) and the vortex oscillator (2) are started simultaneously. The metering pump (16) meterably adds the methanol eluent from the methanol storage tank (14) to each water sample container (9) through the outlet pipe (15). At the same time, the vortex oscillator (2) drives the clamping plate (5) and the water sample container (9) to perform eccentric circular oscillation, so that the methanol eluent forms dynamic turbulence and vortex disturbance as it flows along the inner wall of the water sample container (9), which washes away and desorbs the target adsorbed on the inner wall of the water sample container (9). After the metering pump (16) stops adding liquid, the vortex oscillator (2) continues to run for a preset time to obtain the bottle wall cleaning solution; The first electric telescopic pole (7) drives the lifting ring (13) to rise to the avoidance position; S8, Cleaning fluid collection The clamping plate (5) is transferred from the vibrating end of the vortex oscillator (2) to the operating table (3) by the moving mechanical gripper (11), and the bottle wall cleaning solution in the water sample container (9) is introduced into the solid phase extraction column (401) and collected into the collection bottle (402).

10. The application of the combined method of elution of water sample container wall residue and solid phase extraction as described in claim 9 in the pretreatment of water samples for the detection of perfluorinated compounds.

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