Method and system for studying the temporal variation of liquid sample components

Abstract

The present invention provides a method and system for studying the temporal variation of liquid sample components, belonging to the field of food detection technology. The system includes a sample storage device and a sample pre-processing device, and the method includes the following steps: obtaining a sampling time interval △T, judging whether the sampling time interval △T is ≥ a preset sampling time length T0; if so, judging whether a cleaning operation instruction is completed, and if the cleaning operation instruction is not completed, executing the cleaning operation instruction; if so, executing the sampling operation instruction; judging whether the sampling operation instruction is completed, and if so, making the sampling time interval △T=0, and executing the cleaning operation instruction. On the one hand, the system realizes long-term stable sampling from the sample storage device, and the storage environment of the sample is traceable, thereby improving the reference and scientific nature of the research results. On the other hand, based on magnetic adsorption materials, efficient and rapid enrichment of target components is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of food detection, and in particular relates to a method and system for studying the temporal variation patterns of liquid sample components. Background Art

[0002] In the field of food testing science, it is often necessary to investigate the temporal changes in the content of a specific component or a group of specific components in liquid samples. For example, it is necessary to investigate the temporal migration of plasticizers in edible oil samples; to investigate the temporal transformation of flavor substances in wine samples; and to investigate the compositional changes of wolfberry polysaccharides in wolfberry puree or beverages.

[0003] In existing techniques, multiple samples from the same or different batches, stored at different times, are often selected to investigate the content or composition of a specific component. However, due to variations in material sources, storage environments, and containers, even if storage times are controllable, the resulting findings are subject to numerous other factors, resulting in limited reference value. Summary of the Invention

[0004] Based on this, the present invention provides a system for studying the temporal changes of liquid sample components, in order to solve the technical problem in the prior art that due to differences in material sources, storage environments and containers, there are too many other accidental change factors, and the final research results have low reference value.

[0005] The present invention also provides a method for studying the temporal variation of liquid sample components. Based on the above system, an automatic and scientific investigation of the temporal variation of liquid sample components is achieved.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] A system for studying temporal changes in components of a liquid sample, comprising:

[0008] A sample storage device for storing liquid samples to be investigated;

[0009] The sample storage device comprises a container body, the container body is provided with at least one sample sampling tube, and the sample sampling tube is provided with a sampling control valve;

[0010] A first cleaning agent feeding pipe is provided on the sample sampling pipe, and a first cleaning agent feeding control valve is provided on the first cleaning agent feeding pipe; and

[0011] A sample pre-treatment device, used for pre-treating the liquid sample from the sample collection tube;

[0012] The sample pre-treatment device includes an extraction cup, an auxiliary heating component and a solid-liquid separation component;

[0013] The extraction cup is provided with a sample feeding tube, and the sample feeding tube is connected to the sample extraction tube;

[0014] The extraction cup is further provided with a desorbent feed pipe for introducing a desorbent into the extraction cup and a second cleaning agent feed pipe for introducing a detergent into the extraction cup, the desorbent feed pipe being provided with a desorbent feed control valve, and the second cleaning agent feed pipe being provided with a second cleaning agent feed control valve; a drain pipe is provided at the bottom of the extraction cup, and a drain control valve is provided on the drain pipe;

[0015] The auxiliary heating assembly includes a hot air feed pipe connected to the extraction cup, and the hot air feed pipe is provided with a hot air feed control valve and a hot air heater;

[0016] The solid-liquid separator includes at least one electromagnet, which is disposed in the extraction cup; and the electromagnet is electrically connected to a relay switch.

[0017] Preferably, the system for studying the temporal variation of liquid sample components further comprises:

[0018] A timing device for recording the interval between two adjacent samplings;

[0019] A microcontroller is electrically connected to the timing device, the sampling control valve, the first cleaning agent feed control valve, the desorbent feed control valve, the second cleaning agent feed control valve, the drain control valve, the hot air feed control valve, the hot air heater and the relay switch.

[0020] Preferably, an elastic airbag is provided in the container body, and the elastic airbag divides the interior of the container body into an air storage chamber and a liquid storage chamber, and the volume of the liquid storage chamber decreases as the volume of the air storage chamber increases; an air supply pipe is provided on the air storage chamber, and an airbag air intake control valve is provided on the air supply pipe.

[0021] Preferably, a liquid level sensor is provided on the liquid storage chamber, and the airbag air intake control valve and the liquid level sensor are electrically connected to the microcontroller.

[0022] Preferably, a constant temperature component for maintaining a stable temperature inside the container body is provided on the outside of the container body, and the constant temperature component is provided with a temperature output control component, and the temperature output control component is electrically connected to the microcontroller.

[0023] Preferably, a purge gas feed pipe is provided on the first cleaning agent feed pipe and the second cleaning agent feed pipe respectively, a purge gas feed control valve is provided on the purge gas feed pipe, and the purge gas feed control valve is electrically connected to the microcontroller.

[0024] Preferably, the system for studying the temporal variation of liquid sample components further comprises:

[0025] A sample detection device, wherein the sample detection device includes at least one of a gas chromatograph and a mass spectrometer.

[0026] A method for studying the temporal variation of components of a liquid sample, based on the system for studying the temporal variation of components of a liquid sample as described above, comprises the following steps:

[0027] S01 obtains the sampling time interval △T, determines whether the sampling time interval △T is ≥ the preset sampling time T0;

[0028] S02. If yes, it is determined whether the cleaning operation instruction is completed. If the cleaning operation instruction is not completed, execute the cleaning operation instruction;

[0029] S03. If yes, execute the sampling operation instruction;

[0030] S04 determines whether the sampling operation instruction is completed, and if so, the sampling time interval △ T = 0, and execute the cleaning operation instruction;

[0031] The sampling operation instruction includes:

[0032] Open the sampling control valve to collect a preset volume of sample into the extraction cup;

[0033] Close the sampling control valve, open the hot air feed control valve and the hot air heater, and introduce hot gas with a temperature of ≥ 60° C. into the extraction cup for bubbling adsorption for 2 min-20 min;

[0034] Close the hot air feed control valve and the hot air heater, open the relay switch, open the drain control valve, and separate the magnetic adsorption material and the sample;

[0035] Close the relay switch, close the drain control valve, open the desorbent feed control valve, and introduce desorbent into the extraction cup;

[0036] Close the desorbent feed valve, open the hot air feed control valve, and introduce gas into the extraction cup for bubbling desorption for 2 min to 20 min;

[0037] Close the hot air feed control valve, open the relay switch, open the drain control valve, and separate the magnetic adsorption material and the desorption liquid;

[0038] Close the relay switch, close the drain control valve, open the nitrogen blow control valve, blow dry the desorption liquid with nitrogen, and obtain a sample to be tested;

[0039] Close the nitrogen blow control valve, transfer the sample to be tested to the sample testing device for testing, and the sampling operation instruction ends;

[0040] The cleaning operation instructions include:

[0041] Close the sampling control valve, open the first cleaning agent feed control valve, and pass the cleaning agent into the sample sampling tube for 3 minutes to 10 minutes to clean the sample sampling tube;

[0042] Opening the second cleaning agent feed control valve to introduce a predetermined volume of cleaning agent into the extraction cup;

[0043] Open the hot air feed control valve, introduce gas into the extraction cup, and perform bubbling cleaning for 2 minutes to 20 minutes;

[0044] Close the hot air feed control valve, open the relay switch, open the drain control valve, and separate the magnetic adsorption material and the cleaning liquid;

[0045] Repeat the above steps 2-5 times, and the sampling operation instruction ends.

[0046] Preferably, the sampling operation instruction further includes:

[0047] The air bag air intake control valve is opened to introduce gas into the air storage chamber so that the liquid level in the liquid storage chamber remains stable.

[0048] Preferably, the cleaning operation instruction further includes:

[0049] Open the purge gas feed control valve to purge the sample sampling tube and the extraction cup.

[0050] Compared with the prior art, the present invention has at least the following advantages:

[0051] The present invention provides a system for studying the temporal changes of liquid sample components. A sample storage device and a sample pre-treatment device are provided. The sample to be tested is stored in the storage device. As the investigation time continues, the sample is extracted from the sample storage device at a predetermined time point and simultaneously sent to the sample pre-treatment device. In the sample pre-treatment device, a magnetic adsorption material is used to enrich the target component in the sample before detection. On the one hand, the system realizes long-term stable sampling from the sample storage device. During the sampling process, the disturbance to the sample system is reduced, and the storage environment of the sample is traceable, thereby improving the reference and scientific nature of the investigation results. On the other hand, a sample pre-treatment device is provided, which is based on a magnetic adsorption material, especially based on a magnetic layered double hydroxide-metal organic framework Fe3O4@ZnAl-LDH / ZIF-8, to realize efficient and rapid enrichment of the target component.

[0052] The present invention also provides a method for studying the temporal variation of liquid sample components. Based on the above system, the automation of sampling and sample pre-treatment is achieved, the workload of the research work is reduced, and the accuracy of the research results is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the equipment flow of a system for studying the temporal variation of liquid sample components in one embodiment.

[0054] Figure 2 1 is a process flow chart of a method for studying the temporal variation of liquid sample components in one embodiment.

[0055] In the figure: a system 10 for studying the temporal variation of liquid sample components, a sample storage device 100, a container body 110, a sample collection tube 111, a first cleaning agent feed tube 112, a purge gas feed tube 113, an elastic airbag 120, an air storage chamber 130, an air supply tube 131, a liquid storage chamber 140, a thermostatic assembly 150, a sampling control valve 101, a first cleaning agent feed control valve 102, an airbag air inlet control valve 103, a liquid level sensor 104, and a purge gas feed control valve 115. 05. Sample pretreatment device 200, extraction cup 210, sample feed pipe 211, desorbent feed pipe 212, second cleaning agent feed pipe 213, drain pipe 214, auxiliary heating component 220, hot air feed pipe 221, hot air heater 222, solid-liquid separation element 230, desorbent feed control valve 201, second cleaning agent feed control valve 202, drain control valve 203, hot air feed control valve 204, relay switch 205, timing device 300, microcontroller 400. DETAILED DESCRIPTION

[0056] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The following will further describe the technical solution of the present invention in conjunction with the drawings of the embodiments of the present invention, and the present invention is not limited to the following specific embodiments.

[0057] It should be understood that the same or similar numbers in the drawings of the embodiments correspond to the same or similar parts. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom" and the like indicating an orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0058] In one embodiment, a system 10 for studying temporal changes in liquid sample components is used to investigate temporal changes in the composition and content of components in liquid samples. For example, this can be used to investigate temporal migration of plasticizers in edible oil samples, temporal transformation of flavor compounds in wine samples, and temporal changes in the composition of wolfberry polysaccharides in wolfberry puree or beverages.

[0059] The system 10 for studying the temporal variation of liquid sample components includes a sample storage device 100 and a sample pre-processing device 200. The sample storage device 100 is used to store the liquid sample to be studied, and the sample pre-processing device 200 is used to pre-process the liquid sample from the sample collection tube.

[0060] The sample storage device 100 includes a container body 110, which is provided with at least one sample collection tube 111, and a sampling control valve 101 is provided on the sample collection tube 111. A first cleaning agent feed tube 112 is provided on the sample collection tube 111, and a first cleaning agent feed control valve 102 is provided on the first cleaning agent feed tube 112.

[0061] The sample pretreatment device 200 includes an extraction cup 210, an auxiliary heating assembly 220, and a solid-liquid separator 230. The extraction cup 210 is provided with a sample feed pipe 211, which is connected to the sample extraction pipe 111. The extraction cup 210 is also provided with a desorbent feed pipe 212 for introducing a desorbent into the extraction cup 210, and a second cleaning agent feed pipe 213 for introducing a detergent into the extraction cup 210. The desorbent feed pipe 212 is provided with a desorbent feed control valve 201, and the second cleaning agent feed pipe 213 is provided with a second cleaning agent feed control valve 202. A drain pipe 214 is provided at the bottom of the extraction cup 210, and a drain control valve 203 is provided on the drain pipe 214.

[0062] The auxiliary heating assembly 220 includes a hot air feed pipe 221 connected to the extraction cup 210 . The hot air feed pipe 221 is provided with a hot air feed control valve 204 and a hot air heater 222 .

[0063] The solid-liquid separator 230 includes at least one electromagnet, which is disposed in the extraction cup 210 and is electrically connected to a relay switch 205 .

[0064] In the above embodiment, when investigating the temporal changes in the composition or content of a liquid sample, a magnetic adsorbent material capable of electromagnetic separation is first added to the extraction cup 210. Preferably, the magnetic adsorbent material can be a magnetic layered double hydroxide-metal organic framework (Fe3O4@ZnAl-LDH / ZIF-8). The liquid sample is first stored in the container body 110. Depending on the research needs, the sampling control valve 101 is opened periodically or irregularly to withdraw a predetermined amount of sample into the extraction cup 210. The hot air feed control valve 204 and the hot air heater 222 are opened to bubble hot gas at a temperature ≥ 60°C into the extraction cup 210. Bubbling is continued for 2-20 minutes to ensure that specific components in the sample are fully adsorbed on the magnetic adsorbent material. After bubbling is completed, the relay switch 205 is opened, energizing the electromagnet, causing the magnetic adsorbent material to be attracted by the electromagnet. The liquid discharge control valve 203 is opened to discharge the waste liquid from the extraction cup 210. After draining is complete, the drain control valve 203 is closed, and the relay switch 205 is closed. The desorbent feed control valve 201 is opened, and desorbent is introduced into the extraction cup 210. The hot air feed control valve 204 is opened to initiate bubbling to elute the specific components adsorbed on the magnetic adsorption material. After elution is complete, the relay switch 205 is opened to energize the electromagnet, which attracts the magnetic adsorption material. The drain control valve 203 is then opened to drain the desorbed liquid. After repeating the desorption process 2-3 times, the desorbed liquid is collected and, after further processing, analyzed for component composition and content using a gas chromatograph and / or mass spectrometer.

[0065] After the desorption liquid is removed, the second cleaning agent feed control valve 202 is opened to introduce cleaning agent into the extraction cup 210 to clean the extraction cup 210, the magnetic adsorption material, and related piping and accessories before use. Generally, the magnetic adsorption material is reusable and can be replaced as needed.

[0066] Preferably, to achieve automatic sampling, improve the controllability of sampling time, and further improve research accuracy, the system 10 for studying the temporal variation of liquid sample components further includes a timing device 300 and a microcontroller 400. The timing device 300 can be a timing module integrated into the microcontroller 400, which is used to record the interval between two adjacent samplings.

[0067] The microcontroller 400 is electrically connected to the timing device 300 , the sampling control valve 101 , the first cleaning agent feed control valve 102 , the desorbent feed control valve 201 , the second cleaning agent feed control valve 202 , the drain control valve 203 , the hot air feed control valve 204 , the hot air heater 212 , and the relay switch 205 .

[0068] The sampling and pre-processing steps are automatically performed according to the execution program pre-written into the microcontroller 400. Specifically, a method for studying the temporal variation of liquid sample components is provided. Based on the system 10 for studying the temporal variation of liquid sample components, the method includes the following steps:

[0069] S01. Obtain a sampling time interval ΔT and determine whether the sampling time interval ΔT is greater than or equal to a preset sampling time duration T0.

[0070] That is, a preset sampling time T0 is set. The preset sampling time T0 is set according to the actual survey needs. For example, if the actual survey requires the collection of samples every 15 days or 30 days, the preset sampling time T0 is recorded as 15 or 30. The timing device 300 records the time interval between two adjacent samplings, compares the time interval with the preset sampling time T0, and when the sampling time interval △T is greater than or equal to the preset sampling time T0, the sampling time is available and sampling is required. It should be noted that after each sampling, the sampling time interval is reset to 0 and begins to accumulate again.

[0071] S02. If yes, determine whether the cleaning operation instruction is completed; if the cleaning operation instruction is not completed, execute the cleaning operation instruction.

[0072] When the sampling interval ΔT meets the preset sampling duration T0, before entering the sampling operation, it is first determined whether the cleaning operation instruction is completed. If, under certain conditions, the cleaning operation instruction is not completed, the cleaning operation instruction is first executed to clean the extraction cup 210 and related pipelines and accessories.

[0073] S03. If yes, execute the sampling operation instruction.

[0074] When the sampling time interval ΔT meets the preset sampling time requirement T0 and the cleaning operation instruction has been executed, the sampling condition is met, and the microcontroller 400 executes the sampling operation instruction to collect the sample to be tested and pre-process the sample.

[0075] S04. Determine whether the sampling operation instruction is completed. If so, set the sampling time interval ΔT to 0 and execute the cleaning operation instruction.

[0076] After the sampling operation is completed, that is, the sampling operation instruction is completed, the timing is first restarted, and then the cleaning operation instruction is executed to clean the extraction cup and related pipelines, equipment, etc. to prepare for the next sampling operation.

[0077] Specifically, the sampling operation instruction includes the following steps:

[0078] T01. Open the sampling control valve 101 and collect a preset volume of sample into the extraction cup 210.

[0079] When sampling conditions are met, the sampling control valve 101 is opened. Under the action of pressure or power, a preset volume of sample is collected from the container body 110 and delivered to the extraction cup 210 through the sample feed tube 211. It should be noted that before sampling, it is necessary to confirm that a magnetic adsorption material is added to the extraction cup 210. Preferably, the magnetic adsorption material can be a magnetic layered double hydroxide-metal organic framework Fe3O4@ZnAl-LDH / ZIF-8.

[0080] T02. Close the sampling control valve 101, open the hot air feed control valve 204 and the hot air heater 222, and introduce hot gas with a temperature of ≥ 60°C into the extraction cup 210 for bubbling adsorption for 2-20 minutes.

[0081] Close the sampling control valve 101 and the sampling is completed. In the extraction cup 210, the sample pretreatment process is carried out. It should be noted that when detecting the change pattern of plasticizers in edible oil over time, when the magnetic adsorption material is a magnetic layered double hydroxide-metal organic framework Fe3O4@ZnAl-LDH / ZIF-8, it is particularly necessary to blow hot gas with a temperature of ≥60°C into the extraction cup 210, otherwise, the enrichment effect of the magnetic adsorption material on the plasticizer will be reduced and the detection result will be inaccurate. Preferably, the hot gas is at least one of nitrogen, air, carbon dioxide, argon and oxygen at 60°C-90°C.

[0082] For example, Fe3O4@ZnAl-LDH / ZIF-8 was added to the extraction cup 210 and heated nitrogen gas at 75°C was blown into the cup 210. This enabled Fe3O4@ZnAl-LDH / ZIF-8 to pretreat edible oil samples, improving the efficiency and accuracy of plasticizer detection. Experiments showed that, using DBP, DEHP, and DIBP as spiked samples, the average recovery rate was 85.6%-103.2% at a spike level of 0.1 mg / kg. Furthermore, using Fe3O4@ZnAl-LDH / ZIF-8 to pretreat edible oil samples shortened the sample pretreatment time and improved the sample pretreatment efficiency. In comparison, when nitrogen gas at room temperature was bubbled into the extraction cup 210 , with DBP, DEHP, and DIBP as spiked samples, at a spike level of 0.1 mg / kg, the average recoveries were 32.1%-45.3%, 27.5%-38.7%, and 30.3%-51.6%.

[0083] T03. Close the hot air feed control valve 204 and the hot air heater 222, open the relay switch 205, open the drain control valve 203, and separate the magnetic adsorption material and the sample.

[0084] After adsorption is completed, the hot air feed control valve 204 and the hot air heater 222 are closed to stop bubbling. The relay switch 205 is turned on to energize the electromagnet and activate its electromagnetic properties. The magnetic adsorption material is adsorbed by the electromagnet. At this time, the drain control valve 203 is opened to drain the residual liquid.

[0085] T04. Close the relay switch 205 , close the drain control valve 203 , open the desorbent feed control valve 201 , and introduce desorbent into the extraction cup 210 .

[0086] After the residual liquid is drained, the drain control valve 203 and relay switch 205 are closed, and a desorbent is introduced into the extraction cup 210 to elute the magnetic adsorbent material. The desorbent is selected from at least one of acetonitrile, ethanol, methanol, ethyl acetate, n-hexane, and acetone. Preferably, the desorbent is acetonitrile, n-hexane, or a mixed solution of n-hexane and acetone. For example, the desorbent is a solution of acetone and n-hexane in a volume ratio of 1:3.

[0087] T05. Close the desorbent feed valve 201, open the hot air feed control valve 204, and introduce gas into the extraction cup for bubbling desorption for 2 min-20 min.

[0088] T06. Close the hot air feed control valve 204, open the relay switch 205, and open the drain control valve 203 to separate the magnetic adsorption material and the desorption liquid.

[0089] It should be noted that, according to process requirements, the desorption process of the magnetic adsorption material of T04-T06 can be repeated 2-3 times to ensure sufficient desorption and improve detection accuracy.

[0090] T07. Close the relay switch 205 and the liquid discharge control valve 203. The sample to be tested is transferred to the sample testing device for testing, and the sampling operation instruction is completed.

[0091] Specifically, the cleaning operation instructions include:

[0092] R01. Close sampling control valve 101, open first cleaning agent feed control valve 102, and flow cleaning agent into sample collection tube 111 for 3-10 minutes to clean sample collection tube 111. Preferably, the cleaning agent is selected from at least one of ethanol, methanol, and hot water.

[0093] R02. Open the second cleaning agent feed control valve 202 and introduce a predetermined volume of cleaning agent into the extraction cup 210.

[0094] R03. Open the hot air feed control valve 204 and introduce gas into the extraction cup 210 for bubbling and cleaning for 2 min-20 min.

[0095] R04. Close the hot air feed control valve 204, open the relay switch 205, open the drain control valve 203, and separate the magnetic adsorption material and the cleaning liquid.

[0096] To ensure thorough cleaning, the above steps may be repeated 2-5 times, and the sampling operation instruction is terminated.

[0097] In a preferred embodiment, in order to facilitate sampling from different positions at any time and avoid disturbing the gas phase space of the sample during the sampling process, an elastic airbag 120 is provided in the container body 110, and the elastic airbag 120 divides the interior of the container body 110 into an air storage chamber 130 and a liquid storage chamber 140. The volume of the liquid storage chamber 140 decreases as the volume of the air storage chamber 130 increases; an air supply pipe 131 is provided on the air storage chamber 130, and an airbag air intake control valve 103 is provided on the air supply pipe 131.

[0098] The sample to be investigated is stored in the liquid storage chamber 140, and a certain pressure is maintained within the gas storage chamber 130, thereby maintaining a certain liquid level in the sample in the liquid storage chamber 140. During sampling, gas is introduced into the gas storage chamber 130, causing the volume of the gas storage chamber 130 to increase and the volume of the liquid storage chamber 140 to decrease, thereby maintaining a balanced liquid level in the sample in the liquid storage chamber 140. This facilitates sampling from the upper layer of the liquid sample. Furthermore, during and after sampling, the volume of the gas storage chamber 130 can be adjusted slightly to maintain a balanced gas pressure within the liquid storage chamber 140, thereby preventing the addition of new gas to the container body and disrupting the sample storage environment. This effectively prevents the formation of a vacuum within the container body 110 as sampling proceeds, which could cause deformation of the container body 110.

[0099] In a specific embodiment, the air storage chamber 130 and the liquid storage chamber 140 are respectively located on both sides of the container body 110. For example, the air storage chamber 130 and the liquid storage chamber 140 are respectively located on the left and right sides of the container body 110. Preferably, the two ends of the elastic airbag 120 are respectively fixed to the upper end surface and the bottom surface of the container body 110, and the elastic airbag 120 bulges from one side of the air storage chamber 130 to the side of the liquid storage chamber 140, forming a hemispherical contact surface. When gas is introduced into the air storage chamber 130, the elastic airbag 120 undergoes elastic deformation under the action of gas pressure, thereby increasing the volume of the air storage chamber 130 and decreasing the volume of the liquid storage chamber 140. In some cases, the elastic airbag 120 can also be designed as a plate-like structure that can be sealed and connected to the side of the container body 110 and can slide along the inside of the container body.

[0100] Preferably, a liquid level sensor 104 is provided on the liquid storage chamber 140 , and the airbag air intake control valve 103 and the liquid level sensor 104 are electrically connected to the microcontroller 400 .

[0101] Based on this, the method for studying the temporal variation of liquid sample components further includes the following steps: opening the airbag air inlet control valve 103 and introducing gas into the air storage chamber 130 to maintain a stable liquid level in the liquid storage chamber 140 .

[0102] In some preferred embodiments, a constant temperature component 150 for maintaining a stable temperature inside the container body is provided on the outside of the container body 110 . The constant temperature component 150 is provided with a temperature output control component, and the temperature output control component is electrically connected to the microcontroller 400 .

[0103] The constant temperature assembly 150 can be an electric heating wire disposed outside the container body 110 or a heating chamber disposed outside the container body 110 capable of receiving a flow of, for example, hot water, hot air, or hot oil. When the sample to be investigated needs to be stored at a constant temperature, the constant temperature assembly 150 operates to regulate the sample temperature, thereby further improving the scientific nature and comparability of the investigation results.

[0104] Preferably, a purge gas feed pipe 113 is provided on the first cleaning agent feed pipe 112 and the second cleaning agent feed pipe 213 respectively, and a purge gas feed control valve 105 is provided on the purge gas feed pipe 113. The purge gas feed control valve 105 is electrically connected to the microcontroller.

[0105] At this time, the cleaning operation instruction further includes: opening the purge gas feed control valve 105 to purge the sample sampling tube 111 and the extraction cup 210 .

[0106] In some embodiments, the system 10 for studying the temporal variation of liquid sample components further comprises: a sample detection device, wherein the sample detection device comprises at least one of a gas chromatograph and a mass spectrometer.

[0107] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A system for studying the temporal variation of liquid sample components, characterized in that: include: A sample storage device for storing liquid samples to be investigated; The sample storage device includes a container body, the container body is provided with at least one sample collection tube, and the sample collection tube is provided with a sampling control valve; an elastic airbag is provided in the container body, and the elastic airbag divides the interior of the container body into an air storage chamber and a liquid storage chamber, and the volume of the liquid storage chamber decreases as the volume of the air storage chamber increases; an air supply tube is provided in the air storage chamber, and the air supply tube is provided with an airbag air intake control valve; A first cleaning agent feeding pipe is provided on the sample sampling pipe, and a first cleaning agent feeding control valve is provided on the first cleaning agent feeding pipe; and A sample pre-treatment device, used for pre-treating the liquid sample from the sample collection tube; The sample pre-treatment device includes an extraction cup, an auxiliary heating component and a solid-liquid separation component; The extraction cup is provided with a sample feeding tube, and the sample feeding tube is connected to the sample extraction tube; The extraction cup is also provided with a desorbent feed pipe for introducing a desorbent into the extraction cup and a second detergent feed pipe for introducing a detergent into the extraction cup. A desorbent feed control valve is provided on the desorbent feed pipe, and a second detergent feed control valve is provided on the second detergent feed pipe. A drain pipe is provided at the bottom of the extraction cup, and a drain control valve is provided on the drain pipe. A magnetic layered double hydroxide-metal organic framework Fe3O4@ZnAl-LDH / ZIF-8 is also provided in the extraction cup. The auxiliary heating assembly includes a hot air feed pipe connected to the extraction cup, and the hot air feed pipe is provided with a hot air feed control valve and a hot air heater; the hot air feed pipe is used to pass hot gas with a temperature of ≥60°C into the extraction cup; The solid-liquid separator includes at least one electromagnet, which is disposed in the extraction cup; the electromagnet is electrically connected to a relay switch; The liquid sample component is the plasticizer in edible oil.

2. The system for studying the temporal variation of liquid sample components according to claim 1, wherein: Also includes: A timing device for recording the interval between two adjacent samplings; A microcontroller is electrically connected to the timing device, the sampling control valve, the first cleaning agent feed control valve, the desorbent feed control valve, the second cleaning agent feed control valve, the drain control valve, the hot air feed control valve, the hot air heater and the relay switch.

3. The system for studying the temporal variation of liquid sample components according to claim 2, wherein: A liquid level sensor is provided on the liquid storage chamber, and the air bag air intake control valve and the liquid level sensor are electrically connected to the microcontroller.

4. The system for studying the temporal variation of liquid sample components according to claim 2, wherein: A constant temperature component for maintaining a stable temperature inside the container body is provided on the outside of the container body. The constant temperature component is provided with a temperature output control component, and the temperature output control component is electrically connected to the microcontroller.

5. The system for studying the temporal variation of liquid sample components according to claim 2, wherein: A purge gas feed pipe is provided on the first cleaning agent feed pipe and the second cleaning agent feed pipe respectively. A purge gas feed control valve is provided on the purge gas feed pipe. The purge gas feed control valve is electrically connected to the microcontroller.

6. The system for studying the temporal variation of liquid sample components according to any one of claims 2 to 5, wherein: Also includes: A sample detection device, wherein the sample detection device includes at least one of a gas chromatograph and a mass spectrometer.

7. A method for studying the temporal variation of liquid sample components, based on the system for studying the temporal variation of liquid sample components according to claim 6, characterized in that: The following steps are involved: S01 obtains the sampling time interval △T, determines whether the sampling time interval △T is ≥ the preset sampling time T0; S02. If yes, it is determined whether the cleaning operation instruction is completed. If the cleaning operation instruction is not completed, execute the cleaning operation instruction; S03. If yes, execute the sampling operation instruction; S04 determines whether the sampling operation instruction is completed, and if so, the sampling time interval △ T = 0, and execute the cleaning operation instruction; The sampling operation instruction includes: Open the sampling control valve to collect a preset volume of sample into the extraction cup; Close the sampling control valve, open the hot air feed control valve and the hot air heater, and introduce hot gas with a temperature of ≥ 60° C. into the extraction cup for bubbling adsorption for 2 min-20 min; Close the hot air feed control valve and the hot air heater, open the relay switch, open the drain control valve, and separate the magnetic filler and the sample; Close the relay switch, close the drain control valve, open the desorbent feed control valve, and introduce desorbent into the extraction cup; Close the desorbent feed control valve, open the hot air feed control valve, and introduce gas into the extraction cup for bubbling desorption for 2 minutes to 20 minutes; Close the hot air feed control valve, open the relay switch, open the drain control valve, and separate the magnetic filler and the desorption liquid; Close the relay switch, close the drain control valve, transfer the sample to be tested to the sample testing device for testing, and the sampling operation instruction ends; The cleaning operation instructions include: Close the sampling control valve, open the first cleaning agent feed control valve, and pass the cleaning agent into the sample sampling tube for 3 minutes to 10 minutes to clean the sample sampling tube; Opening the second cleaning agent feed control valve to introduce a predetermined volume of cleaning agent into the extraction cup; Open the hot air feed control valve, introduce gas into the extraction cup, and perform bubbling cleaning for 2 minutes to 20 minutes; Close the hot air feed control valve, open the relay switch, open the drain control valve, and separate the magnetic filler and the cleaning liquid; Repeat the above cleaning steps 2-5 times, and the cleaning operation instruction ends; The liquid sample component is the plasticizer in edible oil.

8. The method for studying the temporal variation of liquid sample components according to claim 7, wherein: The sampling operation instruction also includes: The air bag air intake control valve is opened to introduce gas into the air storage chamber so that the liquid level in the liquid storage chamber remains stable.

9. The method for studying the temporal variation of liquid sample components according to claim 7, wherein: The cleaning operation instructions also include: Open the purge gas feed control valve to purge the sample sampling tube and the extraction cup.

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