A solid-phase extraction automated flow path system and its usage method

Abstract

The present invention discloses a solid-phase extraction automated flow path system and its usage method. The gas source device of this flow path system is connected to a nitrogen blowing needle; the solvent selection valve is provided with a liquid outlet and multiple liquid inlets, and each liquid inlet is connected to a solvent tank. The solvent selection flow path of the solvent selection valve selectively connects one of the multiple liquid inlets to the liquid outlet; the sampling module includes a six-way valve, an injection pump, a column insertion rod, a sampling needle cleaning tank, a plug, and a sampling needle. A fixed valve port is arranged in the center of the six-way valve, and six switching valve ports are arranged in a circumferential array on the outer circle. The fixed valve port is connected to the injection pump, and the six switching valve ports are sequentially connected to the column insertion rod, the gas source device, the sampling needle cleaning tank, the liquid outlet, the plug, and the sampling needle along the circumferential direction. A first flow path and a second flow path are arranged in the six-way valve. The first flow path switches the fixed valve port to connect to one switching valve port, and at the same time, the second flow path switches to connect to two adjacent switching valve ports. To achieve full-process automatic control of the liquid path and gas path during the solid-phase extraction and nitrogen blowing concentration processes.

Description

Technical Field

[0001] The present invention relates to the technical field of test equipment, and particularly relates to an automated flow path system for solid-phase extraction and a method for using the same. Background Art

[0002] Currently, it is usually necessary to use a solid-phase extraction instrument and a nitrogen blowing instrument in cooperation to complete the processes of solid-phase extraction and nitrogen blowing concentration. After the sample is extracted using the solid-phase extraction instrument, the sample is then transferred to the nitrogen blowing instrument for nitrogen blowing concentration, and the operation process is time-consuming and laborious.

[0003] If an integrated automatic control of the liquid path and gas path during the processes of solid-phase extraction and nitrogen blowing concentration can be achieved through a flow path and gas path switching device, the workload of the experimenter will be greatly reduced, and solid-phase extraction and nitrogen blowing concentration can be realized on one device. Summary of the Invention

[0004] The purpose of the present invention is to provide an automated flow path system for solid-phase extraction and a method for using the same, so as to realize the full-process automatic control of the liquid path and gas path during the processes of solid-phase extraction and nitrogen blowing concentration.

[0005] To achieve the above object, the solution of the present invention is: an automated flow path system for solid-phase extraction, including a gas source device, a solvent selection valve, and a sample injection module;

[0006] The gas source device is connected to a nitrogen blowing needle;

[0007] The solvent selection valve is provided with an outlet and a plurality of inlets, each inlet is connected to a solvent tank, and a solvent selection flow path is provided in the solvent selection valve, and the solvent selection flow path selectively connects one of the plurality of inlets to the outlet;

[0008] The sample injection module includes a six-way valve, an injection pump, a column insertion rod, a sample injection needle cleaning tank, a plug, and a sample injection needle. The column insertion rod is used to insert into an SPE column, and the sample injection needle is used to insert into a sample loading tube or a collection tube. A fixed valve port is provided in the center of the six-way valve, and six switching valve ports are arranged in a circumferential array on the outer circle. The fixed valve port is connected to the injection pump, and the six switching valve ports are sequentially connected to the column insertion rod, the gas source device, the sample injection needle cleaning tank, the outlet, the plug, and the sample injection needle along the circumferential direction. A first flow path and a second flow path are provided in the six-way valve. The first flow path switches the fixed valve port to connect to one of the switching valve ports, and at the same time, the second flow path switches to connect to two adjacent switching valve ports.

[0009] Further, the six switching valve ports sequentially conduct the column insertion rod, the gas source device, the sampling needle cleaning tank, the liquid outlet, the plug, and the sampling needle in the counterclockwise direction along the circumference. The two switching valve ports conducted by the second flow path are adjacent to the switching valve port conducted by the first flow path, and the two switching valve ports conducted by the second flow path are located in the counterclockwise direction of the switching valve port conducted by the first flow path.

[0010] A method for using an automated flow path system for solid-phase extraction. The SPE column includes a first SPE column. The method specifically includes the following steps:

[0011] S1. Activation of the SPE column: Switch the solvent selection valve to make the liquid outlet conduct the solvent tank corresponding to the activation process. Switch the six-way valve to make the first flow path conduct the syringe pump and the liquid outlet on the solvent selection valve. Extract the solvent in the corresponding solvent tank through the syringe pump. Then switch the six-way valve again to make the first flow path conduct the syringe pump and the column insertion rod. Insert the column insertion rod into the first SPE column and push the solvent in the syringe pump through the column insertion rod to pass through the first SPE column.

[0012] S2. Sample loading and column passing: Insert the sampling needle into the sampling tube. Switch the six-way valve to make the first flow path conduct the syringe pump and the sampling needle. Extract the sample liquid in the sampling tube through the syringe pump. Switch the six-way valve again to make the first flow path conduct the syringe pump and the column insertion rod. Push the sample liquid in the syringe pump through the column insertion rod to the first SPE column.

[0013] S3. Rinsing: Repeat step S1 and make the liquid outlet 5 of the solvent selection valve 2 conduct the solvent tank 7 corresponding to the rinsing process.

[0014] S4. Elution: Repeat step S1 and make the liquid outlet 5 of the solvent selection valve 2 conduct the solvent tank 7 corresponding to the elution process. And when pushing the solvent in the syringe pump through the column insertion rod to the first SPE column, make the collection tube receive the extraction liquid discharged after passing through the first SPE column.

[0015] Further, after step S3 is completed, switch the six-way valve to make the second flow path conduct the gas source device and the column insertion rod, and blow air into the SPE column through the column insertion rod to dry the SPE column.

[0016] Further, in step S4, after pushing the solvent in the syringe pump through the column insertion rod to the first SPE column, switch the six-way valve to make the second flow path conduct the gas source device and the column insertion rod, and blow air into the SPE column through the column insertion rod to accelerate elution.

[0017] Further, the multiple solvent tanks include a water storage tank. After step S4 is completed, the solvent selection valve is switched so that the solvent selection flow path conducts the liquid outlet to the water storage tank. The six-way valve is switched so that the first flow path conducts the injection pump to the liquid outlet on the solvent selection valve, causing the injection pump to suck in water and air. The sampling needle is inserted into the collection tube, and the six-way valve is switched so that the first flow path conducts the injection pump to the sampling needle. Then, the water and air in the injection pump are discharged through the sampling needle to the collection tube, and the extraction solution is mixed with water.

[0018] Further, after mixing the extraction solution with water, the injection pump sucks in the extraction solution mixed with water through the sampling needle, inserts the sampling needle into the loading tube, and the injection pump discharges the extraction solution mixed with water into the loading tube.

[0019] Further, the SPE column further includes a second SPE column. After the injection pump discharges the extraction solution mixed with water into the loading tube, the first SPE column is replaced with the second SPE column, and steps S1 - S4 are repeated to finally obtain a secondary extraction solution.

[0020] Further, after repeating steps S1 - S4, the nitrogen blowing needle is inserted into the collection tube, and nitrogen is blown into the collection tube to concentrate the secondary extraction solution.

[0021] Further, after repeating steps S1 - S4, the sampling needle is inserted into the sampling needle cleaning tank, and the six-way valve is switched so that the second flow path conducts the gas source device to the sampling needle cleaning tank to blow nitrogen into the sampling needle cleaning tank to clean the sampling needle.

[0022] After adopting the above solution, the beneficial effects of the present invention are as follows:

[0023] By selectively conducting one of the multiple liquid inlets of the solvent selection valve to the liquid outlet, it is realized that the liquid outlet conducts the solvents required in each step of solid-phase extraction to supply the solvents.

[0024] By switching the six-way valve, the injection pump is respectively conducted to the liquid outlet or the sampling needle or the column insertion rod through the first flow path, and respectively realizes sucking the solvent into the injection pump through the liquid outlet, sucking the sample solution into the injection pump through the sampling needle, and discharging the solvent or sample solution in the injection pump to the SPE column through the column insertion rod for column passing. Then, by switching the solvent selection valve and the six-way valve, the entire process of solid-phase extraction can be automatically completed.

[0025] By switching the six-way valve, the gas source device is also conducted to the column insertion rod or the sampling needle cleaning tank through the second flow path. During the solid-phase extraction process, blowing air into the SPE column through the column insertion rod plays a role in accelerating the column passing rate of the solvent or sample solution and drying the SPE column, and blowing air into the sampling needle cleaning tank makes the cleaning liquid in the sampling needle cleaning tank flow, playing a role in cleaning the sampling needle. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is a schematic diagram of the sampling module when the six-way valve of the present invention is in valve position 1;

[0028] Figure 3 is a schematic diagram of the sampling module when the six-way valve of the present invention is in valve position 2;

[0029] Figure 4 is a schematic diagram of the sampling module when the six-way valve of the present invention is in valve position 3;

[0030] Figure 5 is a schematic diagram of the sampling module when the six-way valve of the present invention is in valve position 4.

[0031] Label description: 1 - gas source device, 2 - solvent selection valve, 28 - water bath tank, 4 - nitrogen blowing needle, 5 - liquid outlet, 6 - liquid inlet, 7 - solvent tank, 8 - solvent selection flow path, 9 - six-way valve, 10 - syringe pump, 11 - column insertion rod, 12 - sampling needle cleaning tank, 13 - plug, 14 - sampling needle, 15 - SPE column, 16 - loading tube, 17 - collection tube, 18 - fixed valve port, 19 - switching valve port, 20 - first flow path, 21 - second flow path, 22 - first switching valve port, 23 - second switching valve port, 24 - third switching valve port, 25 - fourth switching valve port, 26 - fifth switching valve port, 27 - sixth switching valve port. Detailed implementation manners

[0032] The following will make a detailed description of the present invention in conjunction with the accompanying drawings and specific embodiments.

[0033] The present invention provides an automated flow path system for solid-phase extraction, as Figures 1-5 shown, including a gas source device 1, a solvent selection valve 2, and a sampling module;

[0034] The gas source device 1 is connected to a nitrogen blowing needle 4. The gas source device 1 is any existing device capable of supplying nitrogen. The nitrogen blowing needle 4 is used to insert into the collection tube 17. The gas source device 1 blows nitrogen into the collection tube 17 through the nitrogen blowing needle 4 to accelerate the air flow in the collection tube 17, and further accelerate the evaporation of the extraction solution in the collection tube 17, so as to realize the concentration of the extraction solution;

[0035] The solvent selection valve 2 is provided with a liquid outlet 5 and a plurality of liquid inlets 6. Each liquid inlet 6 is connected to a solvent tank 7. The number of the solvent tanks 7 and the types of solvents stored therein are set according to actual needs. In this embodiment, for extracting tetracycline drugs in food, the solvent tanks 7 include a methanol tank, a water storage tank, an EDTA·2Na buffer solution tank, and an oxalic acid-acetonitrile tank. A solvent selection flow path 8 is arranged in the solvent selection valve 2. The solvent selection flow path 8 selectively connects one of the plurality of liquid inlets 6 to the liquid outlet 5. Specifically, the liquid outlet 5 is located at the center of the solvent selection valve 2, and the plurality of liquid inlets 6 are arranged in a surrounding array outside the liquid outlet 5. One end of the solvent selection flow path 8 is connected to the liquid outlet 5 and rotates around the liquid outlet 5 for switching. During the rotation, the other end selectively connects to each liquid inlet 6, thereby realizing selectively connecting one of the plurality of solvent tanks 7 to the liquid outlet 5, and discharging the solvent in the solvent tank 7 through the liquid outlet 5;

[0036] The sample injection module includes a six-way valve 9, an injection pump 10, a column insertion rod 11, a sample injection needle cleaning tank 12, a plug 13, and a sample injection needle 14. The column insertion rod 11 is used to insert into an SPE column 15. The SPE column 15 includes a first SPE column and a second SPE column. The sample injection needle 14 is used to insert into a sample loading tube 16 or a collection tube 17. The injection pump 10, the column insertion rod 11, the sample injection needle 14, and the SPE column 15 are all prior arts and will not be specifically described in this embodiment. The sample injection needle cleaning tank 12 is used to hold the cleaning liquid and supply the sample injection needle 14 to insert. The plug 13 is a device for sealing. A fixed valve port 18 is arranged at the center of the six-way valve 9, and six switching valve ports 19 are arranged in a circumferential array on the outer circle. The fixed valve port 18 is connected to the injection pump 10. The six switching valve ports 19 are sequentially connected to the column insertion rod 11, the gas source device 1, the sample injection needle cleaning tank 12, the liquid outlet 5, the plug 13, and the sample injection needle 14 in the counterclockwise direction along the circumference. A first flow path 20 and a second flow path 21 are arranged in the six-way valve 9. The first flow path 20 and the second flow path 21 rotate around the axis of the fixed valve port. During the rotation, the first flow path 20 switches the fixed valve port 18 to connect to one of the switching valve ports 19, and at the same time, the second flow path 21 switches to connect to two adjacent switching valve ports 19. Specifically, in this embodiment, the two switching valve ports 19 connected by the second flow path 21 are adjacent to the switching valve port 19 connected by the first flow path 20, and the two switching valve ports 19 connected by the second flow path 21 are located in the counterclockwise direction of the switching valve port 19 connected by the first flow path 20.

[0037] Specifically, the six switching valve ports 19 include a first switching valve port 22, a second switching valve port 23, a third switching valve port 24, a fourth switching valve port 25, a fifth switching valve port 26, and a sixth switching valve port 27 arranged in sequence in the counterclockwise direction. The first switching valve port 22 conducts the column plug 11, the second switching valve port 23 conducts the gas source device 1, the third switching valve port 24 conducts the sample injection needle cleaning tank 12, the fourth switching valve port 25 conducts the liquid outlet 5, the fifth switching valve port 26 installs the plug 13, and the sixth switching valve port 27 conducts the sample injection needle 14;

[0038] In this embodiment, four valve positions of the six-way valve 9 are used (each time the first flow path 20 conducts with each switching valve port 19 is a valve position):

[0039] Valve position 1: Refer specifically to Figure 2 As shown, the first flow path 20 conducts the fixed valve port 18 to the fourth switching valve port 25, and the second flow path 21 conducts the fifth switching valve port 26 and the sixth switching valve port 27;

[0040] Valve position 2: Refer specifically to Figure 3 As shown, the first flow path 20 conducts the fixed valve port 18 to the third switching valve port 24, and the second flow path 21 conducts the fourth switching valve port 25 and the fifth switching valve port 26;

[0041] Valve position 3: Refer specifically to Figure 4 As shown, the first flow path 20 conducts the fixed valve port 18 to the first switching valve port 22, and the second flow path 21 conducts the second switching valve port 23 and the third switching valve port 24;

[0042] Valve position 4: Refer specifically to Figure 5 As shown, the first flow path 20 conducts the fixed valve port 18 to the sixth switching valve port 27, and the second flow path 21 conducts the first switching valve port 22 and the second switching valve port 23.

[0043] A method for using a solid-phase extraction automated flow path system, which specifically includes the following steps:

[0044] S1. Activate the SPE column. Switch the solvent selection valve 2 to make the liquid outlet 5 communicate with the solvent tank 7 corresponding to the activation process. Switch the six-way valve 9 to valve position 1 to make the first flow path 20 communicate the injection pump 10 with the liquid outlet 5 on the solvent selection valve 2. Draw the solvent in the corresponding solvent tank 7 through the injection pump 10. Then switch the six-way valve 9 to valve position 3 again to make the first flow path 20 communicate the injection pump 10 with the column insert rod 11. Insert the column insert rod 11 into the first SPE column and push the solvent in the injection pump 10 through the column insert rod 11 to pass through the first SPE column. Specifically, in this embodiment, each time the SPE column is activated, step S1 needs to be repeated 3 times. Each time it is repeated, switch the solvent selection valve 2 to make the liquid outlet 5 communicate with the methanol tank, the water storage tank, and the EDTA·2Na buffer solution tank respectively, that is, use methanol, water, and EDTA·2Na buffer solution to pass through the SPE column once respectively. The number of repetitions is specifically set according to the number of solvent types to be passed through the column, so as to realize switching multiple solvents to pass through the SPE column respectively and achieve the purpose of activating the SPE column;

[0045] S2. Sample loading and column passing. Insert the sampling needle 14 into the sampling tube 16 which contains the sample solution. Switch the six-way valve 9 to valve position 4 to make the first flow path 20 communicate the injection pump 10 with the sampling needle 14. Draw the sample solution in the sampling tube 16 through the injection pump 10. Switch the six-way valve 9 to valve position 3 again to make the first flow path 20 communicate the injection pump 10 with the column insert rod 11. Push the sample solution in the injection pump 10 through the column insert rod 11 to the first SPE column to make the sample solution pass through the first SPE column;

[0046] S3. Elution. Repeat step S1 and make the liquid outlet 5 of the solvent selection valve 2 communicate with the solvent tank 7 corresponding to the elution process. Specifically, in this embodiment, make the liquid outlet 5 communicate with the water storage tank and the methanol tank respectively, and make the injection pump 10 draw water and methanol to pass through the column once respectively to complete the elution process. After step S3 is completed, switch the six-way valve 9 to valve position 4 to make the second flow path 21 communicate the gas source device 1 with the column insert rod 11, and blow air into the SPE column through the column insert rod 11 to dry the SPE column 15;

[0047] S4. Elution. Repeat step S1 and make the liquid outlet 5 of the solvent selection valve 2 communicate with the solvent tank 7 corresponding to the elution process. Specifically, in this embodiment, also use water and methanol to pass through the column once respectively. And when pushing the solvent in the injection pump 10 through the column insert rod 11 to the first SPE column, make the collection tube 17 receive the extract discharged after passing through the first SPE column. Thus, a single solid-phase extraction process of the sample solution is completed;

[0048] Preferably, in step S4, after the solvent in the injection pump 10 is pushed out through the column insertion rod 11 to the first SPE column, switch the six-way valve 9 to valve position 4, so that the second flow path 21 conducts the gas source device 1 and the column insertion rod 11, and blow air into the SPE column 15 through the column insertion rod 11 to accelerate elution.

[0049] In this embodiment, since the sample solution needs to pass through the first SPE column and the second SPE column respectively for two passes of solid-phase extraction, the number of solid-phase extraction passes is determined according to actual needs, and the corresponding SPE column can be added. Specifically, first, dilute the extract in the collection tube 17 and transfer it to the sample loading tube 16. That is, after step S4 is completed, switch the solvent selection valve 2 so that the solvent selection flow path 8 conducts the liquid outlet 5 to the water storage tank, switch the six-way valve 9 to valve position 1, so that the first flow path 20 conducts the injection pump 10 and the liquid outlet 5 on the solvent selection valve 2, so that the injection pump 10 inhales water and air, insert the sampling needle 14 into the collection tube 17, switch the six-way valve 9 to valve position 4, so that the first flow path 20 conducts the injection pump 10 and the sampling needle 14, and then discharge the water and air in the injection pump 10 through the sampling needle 14 to the collection tube 17 to mix the extract and water, and complete the dilution of the extract. In this process, air accelerates the mixing of water and the extract. After mixing the extract and water, make the injection pump 10 inhale the extract mixed with water through the sampling needle 14, insert the sampling needle 14 into the sample loading tube 16, and the injection pump 10 discharges the extract mixed with water into the sample loading tube 16.

[0050] After the injection pump 10 discharges the extract mixed with water into the sample loading tube 16, replace the first SPE column with the second SPE column, and repeat steps S1-S4. When repeating steps S1-S4, in each step, the solvent tank 7 conducted by the solvent selection valve 2 can be different from that in the first time of performing steps S1-S4. In this embodiment, when repeating step S4, an oxalic acid-acetonitrile solution is used for elution to finally obtain a secondary extract.

[0051] After repeating steps S1-S4, insert the nitrogen blowing needle 4 into the collection tube 17 and blow nitrogen into the collection tube 17 to concentrate the secondary extract, thereby completing nitrogen blowing concentration. In this embodiment, to improve the concentration efficiency, the collection tube 17 is inserted in a water bath box 28, and the collection tube 17 is heated by water bath through the water bath box 28.

[0052] After repeating steps S1-S4, insert the sampling needle 14 into the sampling needle cleaning groove 12, switch the six-way valve 9, so that the second flow path 21 conducts the gas source device 1 and the sampling needle cleaning groove 12 to blow nitrogen into the sampling needle cleaning groove 12 to clean the sampling needle 14 and realize the cleaning of the sampling needle.

[0053] The above are only the preferred embodiments of the present invention, and do not limit the design of this case. All equivalent changes made according to the key design of this case fall within the protection scope of this case.

Claims

1. An automated flow path system for solid phase extraction, characterized in that: it includes a gas source device (1), a solvent selection valve (2), and a sampling module; the gas source device (1) is connected to a nitrogen blowing needle (4); the solvent selection valve (2) is provided with a liquid outlet (5) and a plurality of liquid inlets (6), each liquid inlet (6) is connected to a solvent tank (7), a solvent selection flow path (8) is arranged in the solvent selection valve (2), and the solvent selection flow path (8) selectively connects one of the plurality of liquid inlets (6) to the liquid outlet (5); the sampling module includes a six-way valve (9), an injection pump (10), a column insertion rod (11), a sampling needle cleaning tank (12), a plug (13), and a sampling needle (14), the column insertion rod (11) is used to insert into an SPE column (15), the sampling needle (14) is used to insert into a sample loading tube (16) or a collection tube (17), a fixed valve port (18) is arranged in the center of the six-way valve (9), and six switching valve ports (19) are arranged in a circumferential array on the outer circle, and the fixed valve port (18) is connected to the injection pump (10); the six switching valve ports (19) are sequentially connected to the column insertion rod (11), the gas source device (1), the sampling needle cleaning tank (12), the liquid outlet (5), the plug (13), and the sampling needle (14) in a counterclockwise direction along the circumference. A first flow path (20) and a second flow path (21) are arranged in the six-way valve (9). The first flow path (20) and the second flow path (21) rotate around the axis of the fixed valve port. During the rotation process, the first flow path (20) switches the fixed valve port (18) to connect to one of the switching valve ports (19), and at the same time, the second flow path (21) switches to connect to two adjacent switching valve ports (19). The two switching valve ports (19) connected by the second flow path (21) are adjacent to the switching valve port (19) connected by the first flow path (20), and the two switching valve ports (19) connected by the second flow path (21) are located in the counterclockwise direction of the switching valve port (19) connected by the first flow path (20).

2. A method for using the automated flow path system for solid phase extraction according to claim 1, characterized in that: the SPE column (15) includes a first SPE column, and the method specifically includes the following steps: S1. Activation of the SPE column: Switch the solvent selection valve (2) to make the liquid outlet (5) communicate with the solvent tank (7) corresponding to the activation process. Switch the six-way valve (9) to make the first flow path (20) connect the injection pump (10) to the liquid outlet (5) on the solvent selection valve (2). Extract the solvent in the corresponding solvent tank (7) through the injection pump (10). Then switch the six-way valve (9) again to make the first flow path (20) connect the injection pump (10) to the column insertion rod (11). Insert the column insertion rod (11) into the first SPE column, and push the solvent in the injection pump (10) through the column insertion rod (11) to pass through the first SPE column. S2. Sample loading and column passing: Insert the injection needle (14) into the sample loading tube (16), switch the six-way valve (9) to connect the first flow path (20) between the syringe pump (10) and the injection needle (14). Extract the sample solution in the sample loading tube (16) through the syringe pump (10). Then switch the six-way valve (9) again to connect the first flow path (20) between the syringe pump (10) and the column insertion rod (11), and push the sample solution in the syringe pump (10) through the column insertion rod (11) into the first SPE column. S3. Elution: Repeat step S1 and connect the outlet (5) of the solvent selection valve (2) to the solvent tank (7) corresponding to the elution process. S4. Elution: Repeat step S1 and connect the outlet (5) of the solvent selection valve (2) to the solvent tank (7) corresponding to the elution process. When pushing the solvent in the syringe pump (10) through the column insertion rod (11) into the first SPE column, use the collection tube (17) to receive the extract discharged after passing through the first SPE column.

3. The method for using an automated flow path system for solid-phase extraction according to claim 2, wherein: After step S3 is completed, switch the six-way valve (9) to connect the second flow path (21) between the gas source device (1) and the column insertion rod (11), and blow air into the SPE column through the column insertion rod (11) to dry the SPE column (15).

4. The method for using an automated flow path system for solid-phase extraction according to claim 2, wherein: In step S4, after pushing the solvent in the syringe pump (10) through the column insertion rod (11) into the first SPE column, switch the six-way valve (9) to connect the second flow path (21) between the gas source device (1) and the column insertion rod (11), and blow air into the SPE column (15) through the column insertion rod (11) to accelerate elution.

5. The method for using an automated flow path system for solid-phase extraction according to claim 2, wherein: The multiple solvent tanks (7) include a water storage tank. After step S4 is completed, switch the solvent selection valve (2) to connect the solvent selection flow path (8) between the outlet (5) and the water storage tank. Switch the six-way valve (9) to connect the first flow path (20) between the syringe pump (10) and the outlet (5) on the solvent selection valve (2), so that the syringe pump (10) inhales water and air. Insert the injection needle (14) into the collection tube (17), switch the six-way valve (9) to connect the first flow path (20) between the syringe pump (10) and the injection needle (14), and then discharge the water and air in the syringe pump (10) through the injection needle (14) into the collection tube (17) to mix the extract with water.

6. The method for using an automated flow path system for solid-phase extraction according to claim 5, wherein: After mixing the extract with water, make the syringe pump (10) inhale the extract mixed with water through the injection needle (14), insert the injection needle (14) into the sample loading tube (16), and the syringe pump (10) discharges the extract mixed with water into the sample loading tube (16).

7. The method for using an automated flow path system for solid phase extraction according to claim 6, characterized in that: the SPE column (15) further includes a second SPE column. After the injection pump (10) discharges the extraction liquid mixed with water into the sample loading tube (16), the first SPE column is replaced with the second SPE column, and steps S1 - S4 are repeated to finally obtain a secondary extraction liquid.

8. The method for using an automated flow path system for solid phase extraction according to claim 7, characterized in that: after repeating steps S1 - S4, the nitrogen blowing needle (4) is inserted into the collection tube (17), and nitrogen is blown into the collection tube (17) to concentrate the secondary extraction liquid.

9. The method for using an automated flow path system for solid phase extraction according to claim 7, characterized in that: after repeating steps S1 - S4, the injection needle (14) is inserted into the injection needle cleaning tank (12), and the six - way valve (9) is switched so that the second flow path (21) connects the gas source device (1) and the injection needle cleaning tank (12) to conduct, and nitrogen is blown into the injection needle cleaning tank (12) to clean the injection needle (14).

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