Sample preparation device for measuring fluorine content in tea water or tea beverage

Abstract

The invention discloses a sample preparation device for determining the fluorine content in tea water or a tea beverage. The sample preparation device comprises a brewing assembly, a filtering assembly, a liquid receiving assembly and a controller, the brewing assembly comprises a first container, a second container, a heating device and a water adding pump, and a liquid outlet with a filter screen is formed in the bottom of the second container; the filtering assembly comprises an activated carbon filter, a three-way electromagnetic valve and a microfiltration membrane filter which are sequentially arranged below the second container, and an interface at the side part of the three-way electromagnetic valve is connected with a waste liquid pipe; the liquid receiving assembly comprises a rotary table, a rotary drive, a plurality of sample containers arranged around the top of the rotary table and a waste liquid container arranged in the center of the top of the rotary table; the controller is electrically connected with the heating device, the water adding pump, the three-way electromagnetic valve and the rotary drive. According to the invention, preparation and filtration of tea water samples can be automatically completed, and the problems of poor sample preparation repeatability, troublesome operation and high pollution risk existing in manual operation are solved.

Description

Technical Field

[0001] This invention relates to the field of sample preparation technology, and specifically to a sample preparation device for determining the fluoride content in tea or tea beverages. Background Technology

[0002] Fluorine is an essential trace element for the human body (the recommended daily intake is 0.5-1.0 mg), but excessive intake (daily average >4 mg) can lead to dental fluorosis and skeletal fluorosis. Tea contains fluoride, and measuring the fluoride content in tea is of great guiding significance for assessing the health risks of tea consumption.

[0003] Currently, the general procedure for determining the fluoride content of tea is as follows:

[0004] (1) Sample preparation: Based on the tea drinking habits of the population, the tea brewing methods are divided into two types: one is to brew tea leaves according to the time gradient, and the other is to add tea leaves once and add water multiple times to brew tea leaves. When obtaining tea water according to the first brewing method, tea leaves and ultrapure water can be added to beakers and brewed for different times to obtain tea water samples with different brewing times. When obtaining tea water according to the second brewing method, tea leaves can be added to beakers and ultrapure water can be added multiple times to brew tea water samples with multiple water additions.

[0005] (2) Sample purification: First, the tea sample is adsorbed and filtered by activated carbon, the initial filtrate is discarded, and then filtered by a 0.45μm microporous membrane.

[0006] (3) Determination of fluoride ion dissolution: 4.5 mmol / L sodium carbonate and 0.8 mmol / L sodium bicarbonate solution were used as eluents, separated by an AS23 ion chromatography column (4.0 mm × 250 mm), and detected by ion chromatography.

[0007] When determining the fluoride content of tea beverages, the sample processing and determination of tea beverages can be carried out according to the steps (2) and (3) above.

[0008] In existing technologies, the preparation and purification of tea samples require manual intervention, which has the following drawbacks:

[0009] (1) Poor sample preparation repeatability: The error of manually controlling the brewing time and water volume is large. Different operators or different batches of experiments by the same operator can easily lead to deviations in the amount of fluorine dissolved in the sample.

[0010] (2) The operation is troublesome: the sample preparation and purification need to be completed manually in steps, which is troublesome and requires human supervision throughout the process;

[0011] (3) High risk of contamination: During the manual transfer of samples, they are easily contaminated, which may affect the test results. Summary of the Invention

[0012] To address the shortcomings of existing technologies, this invention provides a sample preparation device for determining the fluoride content in tea or tea beverages, which automatically completes the preparation and filtration of tea samples, solving the problems of poor sample preparation repeatability, cumbersome operation, and high risk of contamination associated with manual operation.

[0013] This invention provides a sample preparation apparatus for determining the fluoride content in tea or tea beverages, comprising:

[0014] A brewing assembly, comprising a first container for storing ultrapure water, a second container for brewing tea, a heating device for heating the first container, and a water pump for pumping ultrapure water from the first container into the second container, wherein the bottom of the second container is provided with a drain outlet with a filter screen.

[0015] The filtration assembly includes an activated carbon filter, a three-way solenoid valve, and a microporous membrane filter arranged sequentially below the second container. The activated carbon filter has a first inlet and a first outlet at its upper and lower ends, respectively. The microporous membrane filter has a second inlet and a second outlet at its upper and lower ends, respectively. The first inlet is connected to the drain outlet, the first outlet is connected to the upper interface of the three-way solenoid valve, the second inlet is connected to the lower interface of the three-way solenoid valve, and a waste liquid pipe is connected to the interface on the side of the three-way solenoid valve.

[0016] The liquid receiving assembly includes a turntable located below the second liquid outlet and the waste liquid pipe, a rotary drive for driving the turntable to rotate, multiple sample containers placed around the top of the turntable, and a waste liquid container placed at the center of the top of the turntable. Driving the turntable to rotate allows each sample container placed on the turntable to move sequentially to below the second liquid outlet, and the waste liquid container is located below the outlet end of the waste liquid pipe.

[0017] The controller is electrically connected to the heating device, the water pump, the three-way solenoid valve, and the rotary drive, respectively.

[0018] Furthermore, it also includes a body, with the brewing assembly installed on the upper part of the body, the filter assembly installed in the middle part of the body, and the liquid receiving assembly installed on the lower part of the body.

[0019] Furthermore, the top of the machine body is provided with a first receiving groove, a second receiving groove, and a connecting groove connecting the first receiving groove and the second receiving groove, and the heating device is an electric heating platform provided at the bottom of the first receiving groove;

[0020] A connecting frame is provided between the first container and the second container. The water pump is fixed inside the connecting frame. The water inlet of the water pump is connected to the lower part of the first container through a pipe, and the water outlet of the water pump is connected to the upper part of the second container through a pipe.

[0021] The first container is housed in the first receiving slot and placed on the electric heating platform, the second container is housed in the second receiving slot, and the connecting bracket is housed in the connecting slot;

[0022] A plug tube is fixed to the bottom of the second receiving tank. The upper end of the plug tube is inserted into the drain port, and the lower end of the plug tube extends out from the bottom of the second receiving tank and connects to the first inlet port.

[0023] Furthermore, the top of the fuselage is provided with a top cover.

[0024] Furthermore, a flow meter is installed on the pipe at the inlet or outlet of the water pump, and the flow meter is electrically connected to the controller.

[0025] Furthermore, the bottom of the connecting groove is provided with a conductive male plug, the lower end of which is electrically connected to the controller. The bottom of the connecting frame is provided with a conductive female plug, the upper end of which is electrically connected to the water pump and the flow meter. The upper end of the conductive male plug is inserted into the lower end of the conductive female plug.

[0026] Furthermore, the side of the machine body is provided with a first filter tank and a second filter tank located sequentially below the second container. The top of the first filter tank is provided with a first channel communicating with the drain port. A second channel is provided between the first filter tank and the second filter tank. A third channel is provided at the bottom of the second filter tank. The three-way solenoid valve is installed on the second channel.

[0027] The activated carbon filter includes a first filter support inserted into the first filter tank and an activated carbon filter element installed on the first filter support. The first liquid inlet and the first liquid outlet are located on the upper and lower sides of the activated carbon filter element, respectively, and are respectively provided on the upper and lower surfaces of the first filter support. The first liquid inlet is connected to the first channel, and the first liquid outlet is connected to the second channel. The upper surface of the first filter support is provided with a first sealing ring surrounding the first liquid inlet and sealingly engaging with the top wall of the first filter tank. The lower surface of the first filter support is provided with a second sealing ring surrounding the first liquid outlet and sealingly engaging with the bottom wall of the first filter tank.

[0028] The microporous membrane filter includes a second filter support inserted into the second filter tank and a microporous membrane filter element installed on the second filter support. The second inlet and the second outlet are located on the upper and lower sides of the microporous membrane filter element, respectively, and are respectively disposed on the upper and lower surfaces of the second filter support. The second inlet is connected to the second channel, and the second outlet is connected to the third channel. The upper surface of the second filter support is provided with a third sealing ring that surrounds the second inlet and seals with the top wall of the second filter tank. The lower surface of the second filter support is provided with a fourth sealing ring that surrounds the second outlet and seals with the bottom wall of the second filter tank.

[0029] Furthermore, the first filter support is provided with a first filter element mounting hole, the lower end of the first filter element mounting hole forms a first annular step, and the upper end of the first filter element mounting hole is detachably connected to a first pressure ring. The activated carbon filter element is placed in the first filter element mounting hole and confined between the first annular step and the first pressure ring.

[0030] The second filter support is provided with a second filter element mounting hole, the lower end of the second filter element mounting hole forms a second annular step, and the upper end of the second filter element mounting hole is detachably connected to a second pressure ring. The microporous filter membrane filter element is placed in the second filter element mounting hole and confined between the second annular step and the first pressure ring.

[0031] Furthermore, the lower part of the machine body is provided with a liquid receiving chamber, and the bottom of the machine body is provided with support legs;

[0032] The turntable is rotatably mounted on the upper side of the bottom plate of the liquid receiving chamber. The rotation drive includes a motor, which is fixed to the lower side of the bottom plate of the liquid receiving chamber. The output end of the motor passes through the bottom plate of the liquid receiving chamber and is coaxially and fixedly connected to the turntable.

[0033] The liquid receiving chamber is provided with a pick-up and drop-off window on the front side.

[0034] Furthermore, multiple sample container positioning slots are distributed around the top of the turntable, and a waste liquid container positioning slot is provided at the center of the top of the turntable.

[0035] The beneficial effects of this invention are reflected in:

[0036] The tea brewing and filtration process is as follows: A set amount of tea leaves is placed into the second container, and a water pump is used to draw a set amount of boiling water from the first container and add it to the second container. The tea leaves in the second container are then brewed. After the set brewing time, the upper and side interfaces of the three-way solenoid valve are connected. The tea water in the second container passes through an activated carbon filter and then enters the three-way solenoid valve. It is then discharged through a waste liquid pipe into a waste liquid container in the center of the turntable, thus discarding the initial filtrate. After discarding part of the initial filtrate, the upper and lower interfaces of the three-way solenoid valve are connected. The tea water filtered by the activated carbon filter enters a microporous membrane filter and, after further filtration, enters the sample container on the turntable.

[0037] When brewing tea according to a time gradient, tea leaves and boiling water need to be added to the second container multiple times, and the brewing time should be controlled to be different each time to obtain tea with different brewing time. When collecting tea after each brewing, the turntable can be driven to rotate each sample container to be rotated below the second liquid outlet in sequence, so that tea samples with different brewing time can be collected through each sample container.

[0038] When brewing tea with multiple additions of water after the first brewing and filtration, the water pump can be controlled to automatically add water to the second container for repeated brewing. When collecting the tea water after each brewing, the turntable can be driven to rotate each sample container to the bottom of the second outlet in sequence, so that the tea water samples from multiple brewings can be collected through each sample container.

[0039] This application can automatically prepare and filter tea samples by brewing tea in a time gradient manner or by adding water multiple times after adding tea leaves once. The process is controllable, which helps to standardize sample preparation. The entire process requires very little human intervention and is easy to operate. At the same time, it reduces the risk of sample exposure and contamination. Therefore, it solves the problems of poor sample preparation repeatability, complicated operation, and high risk of contamination that exist in manual operation. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0041] Figure 1 This is a perspective view of the overall structure of an embodiment of the present invention;

[0042] Figure 2 This is an isometric sectional view of the overall structure of an embodiment of the present invention;

[0043] Figure 3A perspective view of the brewing assembly, activated carbon filter, and microporous membrane filter taken out in an embodiment of the present invention;

[0044] Figure 4 An isometric sectional view of the brewing assembly, activated carbon filter, and microporous membrane filter in an embodiment of the present invention;

[0045] Figure 5 This is a perspective view of the brewing component according to an embodiment of the present invention;

[0046] Figure 6 This is an isometric sectional view of the brewing component according to an embodiment of the present invention;

[0047] Figure 7 This is a perspective view of the activated carbon filter and the microporous membrane filter according to an embodiment of the present invention;

[0048] Figure 8 This is an isometric sectional view of the activated carbon filter and the microporous membrane filter according to an embodiment of the present invention.

[0049] In the attached diagram, 100 is the brewing assembly; 110 is the first container; 120 is the second container; 121 is the drain port; 122 is the filter screen; 130 is the heating device; 140 is the water pump; 150 is the connecting frame; 151 is the conductive female connector; 160 is the flow meter; 200 is the filter assembly; 210 is the activated carbon filter; 211 is the first inlet; 212 is the first outlet; 213 is the first filter support; 2131 is the first filter element mounting hole; 2132 is the first annular step; 2133 is the first pressure ring; 214 is the activated carbon filter element; 215 is the first sealing ring; 216 is the second sealing ring; 220 is the three-way solenoid valve; 230 is the microporous membrane filter; 231 is the second inlet; 232 is the second outlet; 233 is the second filter support; and 2331 is the second filter element. Mounting hole; 2332-Second annular step; 2333-Second pressure ring; 234-Microporous filter membrane element; 235-Third sealing ring; 236-Fourth sealing ring; 240-Waste liquid pipe; 300-Liquid receiving assembly; 310-Turntable; 311-Sample container positioning groove; 312-Waste liquid container positioning groove; 320-Rotation drive; 330-Sample container; 340-Waste liquid container; 400-Body; 410-First receiving groove; 420-Second receiving groove; 421-Plug tube; 430-Connecting groove; 431-Conductive male plug; 440-Top cover; 450-First filter tank; 460-Second filter tank; 470-First channel; 480-Second channel; 490-Third channel; 4110-Liquid receiving chamber; 4120-Support leg; 4130-Placement window. Detailed Implementation

[0050] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0051] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0052] like Figures 1-8 As shown, this embodiment of the invention provides a sample preparation device for determining the fluoride content in tea or tea beverages, including a brewing component 100, a filtering component 200, a liquid receiving component 300, a controller, and a body 400.

[0053] The brewing component 100 is installed on the upper part of the body 400, the filter component 200 is installed in the middle part of the body 400, and the liquid receiving component 300 is installed on the lower part of the body 400.

[0054] Reference Figure 5 and Figure 6 The brewing assembly 100 includes a first container 110 for storing ultrapure water, a second container 120 for brewing tea, a heating device 130 for heating the first container 110, and a water pump 140 for pumping ultrapure water from the first container 110 into the second container 120. The bottom of the second container 120 is provided with a drain port 121 with a filter screen 122.

[0055] Reference Figure 2 The filter assembly 200 includes an activated carbon filter 210, a three-way solenoid valve 220, and a microporous membrane filter 230 arranged sequentially below the second container 120. The activated carbon filter 210 has a first inlet 211 and a first outlet 212 at its upper and lower ends, respectively. The microporous membrane filter 230 has a second inlet 231 and a second outlet 232 at its upper and lower ends, respectively. The first inlet 211 is connected to the drain port 121, the first outlet 212 is connected to the interface at the upper end of the three-way solenoid valve 220, the second inlet 231 is connected to the interface at the lower end of the three-way solenoid valve 220, and a waste liquid pipe 240 is connected to the interface on the side of the three-way solenoid valve 220.

[0056] Continue to refer to Figure 2 The liquid receiving assembly 300 includes a turntable 310 located below the second liquid outlet 232 and the waste liquid pipe 240, a rotary drive 320 for driving the turntable 310 to rotate, a plurality of sample containers 330 located around the top of the turntable 310, and a waste liquid container 340 located at the center of the top of the turntable 310. Driving the turntable 310 to rotate allows each sample container 330 located on the turntable 310 to move sequentially below the second liquid outlet 232, and the waste liquid container 340 is located below the outlet end of the waste liquid pipe 240.

[0057] The controller is electrically connected to the heating device 130, the water pump 140, the three-way solenoid valve 220 and the rotary drive 320 respectively. The controller adopts a PLC controller and automates the preparation and filtration process of tea samples through a computer program.

[0058] The tea brewing and filtration process is as follows: A set amount of tea leaves is placed into the second container 120, and the water pump 140 is controlled to draw a set amount of boiling water from the first container 110 and add it to the second container 120. The tea leaves in the second container 120 are then brewed. After the set brewing time, the upper and side interfaces of the three-way solenoid valve 220 are connected. The tea water in the second container 120 passes through the activated carbon filter 210 and then enters the three-way solenoid valve 220. It is then discharged through the waste liquid pipe 240 into the waste liquid container 340 in the middle of the turntable 310, thus discarding the initial filtrate. After discarding part of the initial filtrate, the upper and lower interfaces of the three-way solenoid valve 220 are connected. The tea water filtered by the activated carbon filter 210 enters the microporous membrane filter 230 and, after filtration by the microporous membrane filter 230, enters the sample container 330 on the turntable 310.

[0059] When brewing tea according to a time gradient, tea leaves and boiling water need to be added to the second container 120 multiple times, and the brewing time is controlled to be different each time, so that tea water with different brewing time can be obtained. When collecting tea water after each brewing, the turntable 310 can be driven to rotate to rotate each sample container 330 to the bottom of the second liquid outlet 232 in sequence, so that tea water samples with different brewing time can be collected through each sample container 330.

[0060] When brewing tea with multiple additions of water after the first brewing and filtration, the water pump 140 can be controlled to automatically add water to the second container 120 multiple times for repeated brewing. When collecting tea water after each brewing, the turntable 310 can be driven to rotate each sample container 330 to the bottom of the second liquid outlet 232 in sequence, so that the tea water samples brewed with multiple additions of water can be collected through each sample container 330.

[0061] This application can automatically prepare and filter tea samples by brewing tea in a time gradient manner or by adding water multiple times after adding tea leaves once. The process is controllable, which helps to standardize sample preparation. The entire process requires very little human intervention and is easy to operate. At the same time, it reduces the risk of sample exposure and contamination. Therefore, it solves the problems of poor sample preparation repeatability, complicated operation, and high risk of contamination that exist in manual operation.

[0062] Understandably, this device can also be used to prepare tea beverage samples. During preparation, the tea beverage can be directly added to the second container 120. The upper and side interfaces of the three-way solenoid valve 220 are connected. The tea beverage in the second container 120 passes through the activated carbon filter 210 and then enters the three-way solenoid valve 220. It is then discharged into the waste liquid container 340 in the middle of the turntable 310 through the waste liquid pipe 240, thereby discarding the initial filtrate. After discarding part of the initial filtrate, the upper and lower interfaces of the three-way solenoid valve 220 are connected. The tea beverage filtered by the activated carbon filter 210 enters the microporous membrane filter 230 and, after being filtered by the microporous membrane filter 230, enters the sample container 330 on the turntable 310, thus obtaining the tea beverage sample.

[0063] In some embodiments, refer to Figures 1-6 The top of the body 400 is provided with a first receiving groove 410, a second receiving groove 420 and a connecting groove 430 connecting the first receiving groove 410 and the second receiving groove 420. The heating device 130 is an electric heating platform provided at the bottom of the first receiving groove 410.

[0064] A connecting frame 150 is provided between the first container 110 and the second container 120. A water pump 140 is fixed inside the connecting frame 150. The water inlet of the water pump 140 is connected to the lower part of the first container 110 through a pipe, and the water outlet of the water pump 140 is connected to the upper part of the second container 120 through a pipe.

[0065] The first container 110 is housed in the first receiving groove 410 and placed on the electric heating table, the second container 120 is housed in the second receiving groove 420, and the connecting frame 150 is housed in the connecting groove 430.

[0066] The bottom of the second receiving tank 420 is fixed with a plug tube 421. The upper end of the plug tube 421 is inserted into the drain port 121. The lower end of the plug tube 421 extends out from the bottom of the second receiving tank 420 and is connected to the first inlet port 211.

[0067] In this embodiment, the first container 110 and the second container 120 are connected as a single unit via a connecting bracket 150. This structure is detachable from the main body 400. When inserted into the receiving slot inside the main body 400, the first container 110 is placed on the electric heating platform, which can then heat the first container 110. The drain port 121 at the bottom of the second container 120 connects to the plug tube 421, enabling automatic addition of water, brewing, and draining of tea leaves. Simultaneously, the integrated structure consisting of the first container 110, the second container 120, and the connecting bracket 150 can be pulled out of the main body 400 for easy removal and cleaning. Furthermore, a handle can be provided at the upper end of the connecting bracket 150 to facilitate the removal of this structure from the main body 400.

[0068] In some embodiments, refer to Figure 1 The top of the machine body 400 is provided with a top cover 440. During the tea preparation process, the top cover 440 can be closed to prevent foreign matter from entering the first container 110 and the second container 120. When it is necessary to add water to the first container 110 or tea leaves to the second container 120, the top cover 440 can be opened.

[0069] In some embodiments, refer to Figure 6 A flow meter 160 is installed on the pipe at the inlet or outlet of the water pump 140. The flow meter 160 is electrically connected to the controller, so that the flow meter 160 can detect the amount of water added to the second container 120, thereby improving the accuracy of water addition control. Of course, in other embodiments, the amount of water added to the second container 120 can also be controlled by the operating time of the water pump 140.

[0070] In some embodiments, refer to Figure 2 , Figure 4 and Figure 6 The bottom of the connecting groove 430 is provided with a conductive male plug 431, the lower end of which is electrically connected to the controller. The bottom of the connecting frame 150 is provided with a conductive female plug 151, the upper end of which is electrically connected to the water pump 140 and the flow meter 160. The upper end of the conductive male plug 431 and the lower end of the conductive female plug 151 are inserted into each other. When the integrated structure consisting of the first container 110, the second container 120 and the connecting frame 150 is installed into the body 400, the conductive female plug 151 at the bottom of the connecting frame 150 mates with the conductive male plug 431 at the bottom of the connecting groove 430. This allows the water pump 140 and the flow meter 160 inside the connecting frame 150 to be connected to the controller, enabling power supply and signal transmission to the water pump 140 and the flow meter 160. When the integrated structure is pulled out of the body 400, the conductive female plug 151 and the conductive male plug 431 automatically separate without affecting disassembly.

[0071] In some embodiments, refer to Figure 2 , Figure 4 and Figure 8 The side of the machine body 400 is provided with a first filter tank 450 and a second filter tank 460 located below the second container 120. The top of the first filter tank 450 is provided with a first channel 470 communicating with the drain port 121. A second channel 480 is provided between the first filter tank 450 and the second filter tank 460. A third channel 490 is provided at the bottom of the second filter tank 460. A three-way solenoid valve 220 is installed on the second channel 480.

[0072] The activated carbon filter 210 includes a first filter support 213 inserted into a first filter tank 450 and an activated carbon filter element 214 mounted on the first filter support 213. A first inlet 211 and a first outlet 212 are located on the upper and lower sides of the activated carbon filter element 214, respectively, and are respectively disposed on the upper and lower surfaces of the first filter support 213. The first inlet 211 is connected to the first channel 470, and the first outlet 212 is connected to the second channel 480. The upper surface of the first filter support 213 is provided with a first sealing ring 215 surrounding the first inlet 211 and sealingly engaging with the top wall of the first filter tank 450. The lower surface of the first filter support 213 is provided with a second sealing ring 216 surrounding the first outlet 212 and sealingly engaging with the bottom wall of the first filter tank 450.

[0073] When disassembling the activated carbon filter 210, simply pull it out of the first filter tank 450. When installing the activated carbon filter 210, simply insert it into the first filter tank 450. After the activated carbon filter 210 is inserted, its upper first inlet 211 aligns with the first channel 470 at the top of the first filter tank 450, and its lower first outlet 212 aligns with the second channel 480 at the bottom of the first filter tank 450. Simultaneously, the first inlet 211 is sealed by a first sealing ring 215, and the first outlet 212 is sealed by a second sealing ring 216, ensuring that the discharged tea water can enter the activated carbon filter element 214. This design facilitates the replacement of the activated carbon filter 210. To facilitate insertion and removal of the activated carbon filter 210, a handle is provided at the outer end of the first filter bracket 213.

[0074] The microporous membrane filter 230 includes a second filter support 233 inserted into a second filter tank 460 and a microporous membrane filter element 234 mounted on the second filter support 233. A second inlet 231 and a second outlet 232 are located on the upper and lower sides of the microporous membrane filter element 234, respectively, and are respectively disposed on the upper and lower surfaces of the second filter support 233. The second inlet 231 is connected to the second channel 480, and the second outlet 232 is connected to the third channel 490. The upper surface of the second filter support 233 is provided with a third sealing ring 235 surrounding the second inlet 231 and sealingly engaging with the top wall of the second filter tank 460. The lower surface of the second filter support 233 is provided with a fourth sealing ring 236 surrounding the second outlet 232 and sealingly engaging with the bottom wall of the second filter tank 460.

[0075] When disassembling the microporous membrane filter 230, simply pull it out of the second filter chamber 460. When installing the microporous membrane filter 230, simply insert it into the second filter chamber 460. After insertion, the second inlet 231 at the top of the microporous membrane filter 230 aligns with the second channel 480 at the top of the second filter chamber 460, and the second outlet 232 at the bottom aligns with the third channel 490 at the bottom of the second filter chamber 460. Simultaneously, the second inlet 231 is sealed by a third sealing ring 235, and the second outlet 232 is sealed by a fourth sealing ring 236, ensuring that the discharged tea can enter the microporous membrane filter element 234. This design facilitates the replacement of the microporous membrane filter 230. To facilitate insertion and removal of the microporous membrane filter 230, a handle is provided at the outer end of the second filter bracket 233.

[0076] In some embodiments, refer to Figure 8 The first filter support 213 is provided with a first filter element mounting hole 2131. The lower end of the first filter element mounting hole 2131 forms a first annular step 2132. The upper end of the first filter element mounting hole 2131 is detachably connected to a first pressure ring 2133. The activated carbon filter element 214 is placed in the first filter element mounting hole 2131 and confined between the first annular step 2132 and the first pressure ring 2133. In this way, when replacing the activated carbon filter 210, only the activated carbon filter element 214 on the first filter support 213 needs to be replaced.

[0077] The second filter support 233 is provided with a second filter element mounting hole 2331. The lower end of the second filter element mounting hole 2331 forms a second annular step 2332. The upper end of the second filter element mounting hole 2331 is detachably connected to a second pressure ring 2333. The microporous filter membrane element 234 is placed in the second filter element mounting hole 2331 and confined between the second annular step 2332 and the first pressure ring 2133. In this way, when replacing the microporous filter membrane 230, only the microporous filter membrane element 234 on the second filter support 233 needs to be replaced.

[0078] In some embodiments, refer to Figure 2 and Figure 4 The lower part of the body 400 is provided with a liquid receiving chamber 4110, and the bottom of the body 400 is provided with a support leg 4120.

[0079] The turntable 310 is rotatably mounted on the upper side of the bottom plate of the liquid receiving chamber 4110. The rotation drive 320 includes a motor, which is fixed to the lower side of the bottom plate of the liquid receiving chamber 4110. The output end of the motor passes through the bottom plate of the liquid receiving chamber 4110 and is coaxially fixedly connected to the turntable 310. In this way, the turntable 310 can be rotated by the motor, so that each sample container 330 placed on the turntable 310 is aligned with the second liquid outlet 232 at the bottom of the microporous membrane filter 230 in sequence.

[0080] The front side of the liquid receiving chamber 4110 is provided with a pick-up and drop window 4130 to facilitate the pick-up and drop of the sample container 330 and the waste liquid container 340 through the pick-up and drop window 4130.

[0081] To facilitate the precise positioning and installation of the sample container 330 and the waste liquid container 340 on the turntable 310, multiple sample container positioning slots 311 are distributed around the top of the turntable 310, and a waste liquid container positioning slot 312 is provided at the center of the top of the turntable 310.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A sample preparation apparatus for determining the fluoride content in tea or tea beverages, characterized in that, include: A brewing assembly, comprising a first container for storing ultrapure water, a second container for brewing tea, a heating device for heating the first container, and a water pump for pumping ultrapure water from the first container into the second container, wherein the bottom of the second container is provided with a drain outlet with a filter screen. The filtration assembly includes an activated carbon filter, a three-way solenoid valve, and a microporous membrane filter arranged sequentially below the second container. The activated carbon filter has a first inlet and a first outlet at its upper and lower ends, respectively. The microporous membrane filter has a second inlet and a second outlet at its upper and lower ends, respectively. The first inlet is connected to the drain outlet, the first outlet is connected to the upper interface of the three-way solenoid valve, the second inlet is connected to the lower interface of the three-way solenoid valve, and a waste liquid pipe is connected to the interface on the side of the three-way solenoid valve. The liquid receiving assembly includes a turntable located below the second liquid outlet and the waste liquid pipe, a rotary drive for driving the turntable to rotate, multiple sample containers placed around the top of the turntable, and a waste liquid container placed at the center of the top of the turntable. Driving the turntable to rotate allows each sample container placed on the turntable to move sequentially to below the second liquid outlet, and the waste liquid container is located below the outlet end of the waste liquid pipe. The controller is electrically connected to the heating device, the water pump, the three-way solenoid valve, and the rotary drive, respectively.

2. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 1, characterized in that, It also includes a body, with the brewing assembly installed on the upper part of the body, the filter assembly installed in the middle part of the body, and the liquid receiving assembly installed on the lower part of the body.

3. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 2, characterized in that, The top of the machine body is provided with a first receiving groove, a second receiving groove, and a connecting groove connecting the first receiving groove and the second receiving groove. The heating device is an electric heating platform located at the bottom of the first receiving groove. A connecting frame is provided between the first container and the second container. The water pump is fixed inside the connecting frame. The water inlet of the water pump is connected to the lower part of the first container through a pipe, and the water outlet of the water pump is connected to the upper part of the second container through a pipe. The first container is housed in the first receiving slot and placed on the electric heating platform, the second container is housed in the second receiving slot, and the connecting bracket is housed in the connecting slot; A plug tube is fixed to the bottom of the second receiving tank. The upper end of the plug tube is inserted into the drain port, and the lower end of the plug tube extends out from the bottom of the second receiving tank and connects to the first inlet port.

4. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 3, characterized in that, The top of the fuselage is equipped with a top cover.

5. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 3, characterized in that, A flow meter is installed on the pipe at the inlet or outlet of the water pump, and the flow meter is electrically connected to the controller.

6. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 5, characterized in that, The bottom of the connecting groove is provided with a conductive male plug, the lower end of which is electrically connected to the controller. The bottom of the connecting frame is provided with a conductive female plug, the upper end of which is electrically connected to the water pump and the flow meter. The upper end of the conductive male plug and the lower end of the conductive female plug are inserted into each other.

7. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 2, characterized in that, The side of the machine body is provided with a first filter tank and a second filter tank located sequentially below the second container. The top of the first filter tank is provided with a first channel communicating with the drain port. A second channel is provided between the first filter tank and the second filter tank. A third channel is provided at the bottom of the second filter tank. The three-way solenoid valve is installed on the second channel. The activated carbon filter includes a first filter support inserted into the first filter tank and an activated carbon filter element installed on the first filter support. The first liquid inlet and the first liquid outlet are located on the upper and lower sides of the activated carbon filter element, respectively, and are respectively provided on the upper and lower surfaces of the first filter support. The first liquid inlet is connected to the first channel, and the first liquid outlet is connected to the second channel. The upper surface of the first filter support is provided with a first sealing ring surrounding the first liquid inlet and sealingly engaging with the top wall of the first filter tank. The lower surface of the first filter support is provided with a second sealing ring surrounding the first liquid outlet and sealingly engaging with the bottom wall of the first filter tank. The microporous membrane filter includes a second filter support inserted into the second filter tank and a microporous membrane filter element installed on the second filter support. The second inlet and the second outlet are located on the upper and lower sides of the microporous membrane filter element, respectively, and are respectively disposed on the upper and lower surfaces of the second filter support. The second inlet is connected to the second channel, and the second outlet is connected to the third channel. The upper surface of the second filter support is provided with a third sealing ring that surrounds the second inlet and seals with the top wall of the second filter tank. The lower surface of the second filter support is provided with a fourth sealing ring that surrounds the second outlet and seals with the bottom wall of the second filter tank.

8. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 7, characterized in that, The first filter support is provided with a first filter element mounting hole, the lower end of the first filter element mounting hole forms a first annular step, and the upper end of the first filter element mounting hole is detachably connected to a first pressure ring. The activated carbon filter element is placed in the first filter element mounting hole and confined between the first annular step and the first pressure ring. The second filter support is provided with a second filter element mounting hole, the lower end of the second filter element mounting hole forms a second annular step, and the upper end of the second filter element mounting hole is detachably connected to a second pressure ring. The microporous filter membrane filter element is placed in the second filter element mounting hole and confined between the second annular step and the first pressure ring.

9. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 2, characterized in that, The lower part of the machine body is provided with a liquid receiving chamber, and the bottom of the machine body is provided with support legs; The turntable is rotatably mounted on the upper side of the bottom plate of the liquid receiving chamber. The rotation drive includes a motor, which is fixed to the lower side of the bottom plate of the liquid receiving chamber. The output end of the motor passes through the bottom plate of the liquid receiving chamber and is coaxially and fixedly connected to the turntable. The liquid receiving chamber is provided with a pick-up and drop-off window on the front side.

10. The sample preparation apparatus for determining the fluoride content in tea or tea beverages according to claim 9, characterized in that, The top of the turntable is surrounded by multiple sample container positioning slots, and the center of the top of the turntable is provided with a waste liquid container positioning slot.

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