D-lactic acid content determination kit and determination method

Abstract

The present invention discloses a D-lactic acid content determination kit and a determination method, and relates to the technical field of D-lactic acid content determination, the D-lactic acid content determination kit comprises a detection box body, the side of the detection box body is provided with an assembly strip for assembly, and the upper part of the detection box body is provided with a protection cover, a mixing barrel for mixing reagents is arranged on the outermost side of the detection box body on the end side, an auxiliary base is fixedly connected to the interior of the detection box body, a clamping plate is arranged on the upper side of the auxiliary base, and an adjusting mechanism is arranged in the auxiliary base. According to the D-lactic acid content determination kit and the determination method, pyruvic acid is generated from D-lactic acid under the action of D-lactic dehydrogenase, and NAD < + > is reduced to generate NADH; in order to smoothly carry out the reaction, an enzyme is additionally added to further decompose pyruvic acid, NADH is generated and reacts with a specific color developing agent to generate a colored substance with the maximum absorption peak at the position of 450 nm, and the content of D-lactic acid is calculated by detecting the increment of the substance at the position of 450 nm.

Description

Technical Field

[0001] The present invention relates to the technical field of D-lactic acid content determination, and specifically provides a kit and a method for determining D-lactic acid content. Background Art

[0002] D-lactic acid is an optical isomer of lactic acid. Its finished product is a colorless or light yellow viscous liquid with a slightly sour taste. It is easily soluble in water, ethanol, and ether, and insoluble in chloroform. The human body can only slowly metabolize D-lactic acid through specific enzymes (such as D-2-hydroxyacid dehydrogenase). Excessive intake may lead to metabolic acidosis. Therefore, the detection of D-lactic acid content is of great value in medical diagnosis (such as metabolic disorders, acidosis), industrial production (such as biodegradable materials), and scientific research (such as chiral synthesis).

[0003] The prior art (a Chinese patent with the publication number CN101324555A and the publication date December 17, 2008) is a D-lactic acid diagnostic / determination kit using an enzyme colorimetry technique with D-lactic acid specificity. The present invention also relates to the method principle for determining the D-lactic acid concentration, the composition and components of the reagent, and belongs to the technical field of medical / food inspection and determination. The main components of this kit include: buffer solution, coenzyme, D-lactic acid dehydrogenase, and stabilizer; by mixing the sample and the reagent in a certain volume ratio to cause a series of enzymatic reactions, and then placing the reactant under an ultraviolet / visible light analyzer to detect the degree / speed of the absorbance increase at the main wavelength of 340 nm, thereby calculating the concentration of D-lactic acid.

[0004] Although the existing D-lactic acid determination kit can measure it, when the kit body places the reagent tube, it cannot provide stable protection for the reagent tube. At the same time, different reagents require different storage temperatures. When the temperature inside the kit drops, the reagent may become ineffective, which has certain limitations.

[0005] Therefore, we propose a kit and a method for determining D-lactic acid content to solve the problems raised above. Summary of the Invention

[0006] The purpose of the present invention is to provide a kit and a method for determining D-lactic acid content to solve the problems in the above background art, that is, when the current market kit body places the reagent tube, it cannot provide stable protection for the reagent tube. At the same time, different reagents require different storage temperatures. When the temperature inside the kit drops, the reagent may become ineffective, which has certain limitations.

[0007] To achieve the above object, the present invention provides the following technical solutions: a kit and a determination method for determining the content of D-lactic acid, including a detection box body. An assembly strip for assembly is provided on the side of the detection box body, and a protective cover is provided above the detection box body. A mixing cylinder for mixing reagents is provided on the outermost side of the end side of the detection box body. An auxiliary base is fixedly connected inside the detection box body, and a clamping plate is provided on the upper side of the auxiliary base. An adjustment mechanism is provided inside the auxiliary base, and the adjustment mechanism realizes the moving clamping operation of the clamping plate through the gas exchange between the first airbag and the second airbag it includes. A limiting frame is fixedly connected to the inner wall of the detection box body, and a feedback mechanism is provided inside the limiting frame. The feedback mechanism feeds back the temperature inside the detection box body through the change in the position state of the feedback rod it includes.

[0008] Preferably, a docking rod is fixedly connected to the lower surface of the protective cover. A docking groove adapted to the docking rod is opened on the upper surface of the detection box body, and an auxiliary box is fixedly connected below the docking groove.

[0009] Preferably, the adjustment mechanism includes a movable groove opened inside the auxiliary base. A sliding block is nested and connected inside the movable groove. The upper surface of the sliding block is fixedly connected to the lower surface of the clamping plate. A second airbag is fixedly connected between the side of the sliding block and the side wall of the movable groove. The first airbag is fixedly connected inside the auxiliary box, and a communication hose is provided through between the second airbag and the first airbag.

[0010] Preferably, a rotating shaft is rotatably provided at the center of the clamping plate. A limiting plate is fixedly connected to the middle of the outer side of the rotating shaft. A torsion spring is fixedly connected between the upper end side of the limiting plate and the clamping plate. A traction rope is wound around the outer side of the rotating shaft, and the other end of the traction rope is fixedly connected to the upper surface of the auxiliary base.

[0011] Preferably, the sliding block forms a sliding structure with the movable groove through the second airbag. The limiting plate forms a rotating structure with the clamping plate through the rotating shaft, and rubber dots are provided on the inner side of the limiting plate.

[0012] Preferably, an auxiliary shaft is rotatably connected to the center of the movable groove. A turntable is fixedly connected to the outer side of the auxiliary shaft. A rotating rod is hinged to the side of the turntable. A pull rod is fixedly connected to the side of the sliding block, and the inner end of the pull rod is hinged to the other side of the rotating rod.

[0013] Preferably, a button is fixedly connected inside the movable slot, a connecting rod is fixedly connected to the side of the auxiliary shaft, a first magnet is fixedly connected to the outer end of the connecting rod, a limiting rod is nested inside the auxiliary base, a second magnet is fixedly connected to one end of the limiting rod close to the first magnet, and a pressing plate is fixedly connected to one end of the second magnet close to the button. A second spring is fixedly connected between the inner side of the pressing plate and the movable slot. A temperature control tube electrically connected to the button is arranged on the upper surface of the auxiliary base.

[0014] Preferably, the feedback mechanism includes a heat conducting plate, the heat conducting plate is nested on the side of the limiting frame, a shape memory alloy is nested inside the limiting frame, and the side of the shape memory alloy is fixedly connected to the inner end of the heat conducting plate. A contact plate corresponding to the position of the limiting frame is nested on the front side of the detection box body, the contact plate is fixedly connected to the inner end of the feedback rod, and the feedback rod is nested on the detection box body.

[0015] A determination method of a D-lactic acid content determination kit, applied to a D-lactic acid content determination kit as shown in claim 1, includes the following steps: S1: After placing the reagent inside the reagent tube, place the reagent tube inside the corresponding detection box body. At this time, close the protective cover and the detection box body. The second airbag will expand and push the sliding block. Moving the sliding block will drive the clamping plates on both sides to slide towards each other, and initially clamp the reagent tube. At the same time, the rotating shaft rotates under the traction of the traction rope, and drives the limiting plate to rotate inwards synchronously, so as to further resist the reagent tube, prevent the reagent tube from shifting and shaking, and avoid damage to the reagent tube; S2: During the movement of the sliding block, the rotating rod hinged to it is pushed synchronously through the pull rod. At this time, the turntable drives the rotating shaft to rotate synchronously. The rotating rotating shaft can drive the first magnet to rotate through the connecting rod. At this time, the first magnet does not adsorb the second magnet. The pressing plate can slide towards the button under the driving of the elastic force of the second spring, so as to press the button, start the temperature control tube, and perform temperature control processing. When the temperature control of the temperature control tube fails, the shape memory alloy will sense the temperature change and thus bend and deform. The bent shape memory alloy can resist the contact plate and drive the feedback rod to move outwards. The user can observe the position state of the feedback rod to know whether the inside of the detection box body has lost temperature and check the reagent state; S3: D-lactic acid generates pyruvate under the action of D-lactic acid dehydrogenase, and reduces NAD+ to generate NADH; in order to make this reaction proceed smoothly, another enzyme is added to further decompose pyruvate, generating NADH that reacts with a specific chromogenic agent to produce a colored substance with a maximum absorption peak at 450 nm. By detecting the increase in the amount of this substance at 450 nm, the D-lactic acid content is calculated.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: After the protective cover and the detection box body are closed, the first airbag is squeezed by the docking rod arranged below the protective cover. At this time, the gas inside the first airbag is transmitted to the inside of the second airbag through the connecting hose, so as to realize the gas exchange between the first airbag and the second airbag. When the second airbag expands, it will drive the clamping plate to move towards each other through the sliding block, so as to assist in clamping and limiting the reagent tube.

[0017] During the movement of the clamping plate, the rotating shaft can be pulled through the traction of the traction rope, so that the rotating shaft drives the limiting plate to rotate inward. The outward-expanded limiting plate further abuts against the reagent tube, and the friction with the reagent tube is increased by the rubber points arranged on the side, so that the reagent tube can be placed more stably inside the detection box body.

[0018] During the movement of the sliding block, the turntable can be driven to rotate through the mutual cooperation of the pull rod and the rotating rod. At this time, under the drive of the turntable, the rotating shaft can synchronously cause the first magnetic block and the second magnetic block to be misaligned, so that the pressing plate presses the button, and at this time the temperature control tube starts to operate, so that the temperature inside the detection box body can be adjusted according to the needs of different reagents.

[0019] A feedback rod is arranged on the box body of the detection box body. When the temperature inside the detection box body is in a constant state, the position of the feedback rod will not change. When the temperature control tube cannot operate normally and the detection box body loses temperature, the feedback rod will move outwards, so as to feedback the temperature condition inside the detection box body.

[0020] The temperature inside the detection box body can be transmitted to the shape memory alloy through the heat conduction plate. When the temperature changes, the shape memory alloy will deform, so as to squeeze the contact plate and make the feedback rod move outwards. At this time, the user can observe the position distance of the feedback rod to judge whether the detection box body is damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional structure diagram of the present invention; Figure 2 is a three-dimensional sectional structure diagram of the detection box body of the present invention; Figure 3 is a three-dimensional sectional structure diagram of the auxiliary box of the present invention; Figure 4 is a three-dimensional structure diagram of the connecting hose of the present invention; Figure 5 is a three-dimensional structure diagram of the clamping plate of the present invention; Figure 6 is a three-dimensional sectional structure diagram of the clamping plate of the present invention; Figure 7 is a three-dimensional sectional structure diagram of the auxiliary base of the present invention; Figure 8 Schematic three-dimensional structure diagram of the pressing plate of the present invention; Figure 9 Schematic three-dimensional structure diagram of the limiting frame of the present invention; Figure 10 Schematic three-dimensional sectional structure diagram of the limiting frame of the present invention.

[0022] In the figure: 1, detection box body; 2, protective cover; 3, assembly strip; 4, mixing cylinder; 5, docking groove; 6, auxiliary box; 7, first airbag; 8, second airbag; 9, connecting hose; 10, docking rod; 11, auxiliary base; 12, moving groove; 13, auxiliary shaft; 14, rotating shaft; 15, limiting plate; 16, clamping plate; 17, sliding block; 18, towing rope; 19, button; 20, first magnet; 21, second magnet; 22, connecting rod; 23, rotating rod; 24, limiting rod; 25, torsion spring; 26, temperature control pipe; 27, turntable; 28, pressing plate; 29, second spring; 30, limiting frame; 31, heat conducting plate; 32, shape memory alloy; 33, feedback rod; 34, resisting plate; 35, pull rod. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment 1: As Figures 1-4For the technical solution shown, the present invention provides the following technical solution: a kit and a determination method for determining the content of D-lactic acid, discloses an adjustment mechanism, through which the reagent tube can be clamped and limited to prevent the reagent tube from shifting and shaking: an assembly strip 3 for assembly is provided on the side of the detection box body 1, and a protective cover 2 is provided above the detection box body 1, and a mixing cylinder 4 for mixing the reagent is provided on the outermost side of the detection box body 1 at the end side. An auxiliary base 11 is fixedly connected inside the detection box body 1, and a clamping plate 16 is provided on the upper side of the auxiliary base 11. An adjustment mechanism is provided inside the auxiliary base 11, and the adjustment mechanism realizes the moving clamping operation of the clamping plate 16 through the gas exchange between the first airbag 7 and the second airbag 8 it includes. A docking rod 10 is fixedly connected to the lower surface of the protective cover 2, and a docking groove 5 adapted to the docking rod 10 is opened on the upper surface of the detection box body 1, and an auxiliary box 6 is fixedly connected below the docking groove 5. The adjustment mechanism includes a movable groove 12 opened inside the auxiliary base 11, and a sliding block 17 is nested inside the movable groove 12. The upper surface of the sliding block 17 is fixedly connected to the lower surface of the clamping plate 16, and a second airbag 8 is fixedly connected between the side of the sliding block 17 and the side wall of the movable groove 12. The first airbag 7 is fixedly connected inside the auxiliary box 6, and a communication hose 9 is provided through between the second airbag 8 and the first airbag 7. A rotating shaft 14 is rotatably provided at the center of the clamping plate 16, and a limiting plate 15 is fixedly connected to the middle part of the outer side of the rotating shaft 14. A torsion spring 25 is fixedly connected between the upper end side of the limiting plate 15 and the clamping plate 16. A traction rope 18 is wound around the outer side of the rotating shaft 14, and the other end of the traction rope 18 is fixedly connected to the upper surface of the auxiliary base 11. The sliding block 17 forms a sliding structure with the movable groove 12 through the second airbag 8, the limiting plate 15 forms a rotating structure with the clamping plate 16 through the rotating shaft 14, and rubber points are provided inside the limiting plate 15.

[0025] After placing the reagent inside the reagent tube, place the reagent tube inside the corresponding detection box body 1. At this time, align the docking rod 10 provided at the lower end of the protective cover 2 with the docking groove 5, so as to close the protective cover 2 and the detection box body 1. At this time, the docking rod 10 docks into the auxiliary box 6, thereby squeezing the first airbag 7. When the first airbag 7 is squeezed, the gas inside it will be transmitted to the inside of the second airbag 8 through the communication hose 9, so that the second airbag 8 expands and pushes the sliding block 17, so that the sliding block 17 drives the clamping plates 16 on both sides to slide towards each other and initially clamp the reagent tube. When the clamping plate 16 is moving, the fixed traction rope 18 at the end will traction the rotating shaft 14 at this time, so that the rotating shaft 14 rotates. The rotating rotating shaft 14 can drive the limiting plate 15 to rotate inwards synchronously, so as to further resist the reagent tube and prevent the reagent tube from shifting and shaking, and avoid damage to the reagent tube.

[0026] Example 2: As Figures 3-7 shown in the technical solution, the present invention provides the following technical solution: a kit and a determination method for measuring the D-lactic acid content, which discloses a temperature control tube 26. Through the driving action of an adjustment mechanism, the temperature control tube 26 can be synchronously started to perform temperature control processing on the inside of the detection box body 1: a auxiliary shaft 13 is rotatably connected to the center of the movable groove 12, a turntable 27 is fixedly connected to the outside of the auxiliary shaft 13, and a rotating rod 23 is hinged to the side of the turntable 27. A pull rod 35 is fixedly connected to the side of the sliding block 17, and the inner end of the pull rod 35 is hinged to the other side of the rotating rod 23. A button 19 is fixedly connected to the inside of the movable groove 12, a connecting rod 22 is fixedly connected to the side of the auxiliary shaft 13, and a first magnetic block 20 is fixedly connected to the outer end of the connecting rod 22. A limiting rod 24 is nested in the inside of the auxiliary base 11, and a second magnetic block 21 is fixedly connected to one end of the limiting rod 24 close to the first magnetic block 20. A pressing plate 28 is fixedly connected to one end of the second magnetic block 21 close to the button 19. A second spring 29 is fixedly connected between the inner side of the pressing plate 28 and the movable groove 12. A temperature control tube 26 electrically connected to the button 19 is arranged on the upper surface of the auxiliary base 11.

[0027] During the movement of the sliding block 17, the pull rod 35 can be synchronously driven to move, so as to synchronously push the rotating rod 23 hinged thereto through the pull rod 35. At this time, the rotating rod 23 can drive the turntable 27 to rotate. When the turntable 27 rotates, the rotating shaft 14 can be synchronously driven to rotate. The rotating rotating shaft 14 can drive the first magnetic block 20 to rotate through the connecting rod 22. At this time, the first magnetic block 20 does not adsorb the second magnetic block 21. At this time, the second magnetic block 21 does not attract the limiting rod 24. The pressing plate 28 can slide towards the side of the button 19 under the driving of the elastic force of the second spring 29, so as to press the button 19, starting the temperature control tube 26 to perform temperature control processing.

[0028] Example 3: As Figure 3 、 Figure 9 and Figure 10For the technical solution shown, the present invention provides the following technical solution: a kit for determining the D-lactic acid content and a determination method, which discloses a feedback mechanism. Through the feedback mechanism, the temperature state inside the detection box body 1 can be fed back: a limiting frame 30 is fixedly connected to the inner wall of the detection box body 1, and a feedback mechanism is arranged inside the limiting frame 30. The feedback mechanism realizes the feedback of the temperature inside the detection box body 1 through the change in the position state of the feedback rod 33 it includes. The feedback mechanism includes a heat conduction plate 31, the heat conduction plate 31 is nested on the side of the limiting frame 30, a shape memory alloy 32 is nested inside the limiting frame 30, and the side of the shape memory alloy 32 is fixedly connected to the inner end of the heat conduction plate 31. A contact plate 34 corresponding to the position of the limiting frame 30 is nested on the front side of the detection box body 1, and the contact plate 34 is fixedly connected to the inner end of the feedback rod 33, and the feedback rod 33 is nested on the detection box body 1.

[0029] When the temperature control of the temperature control tube 26 fails, the heat conduction plate 31 transfers the temperature inside the detection box body 1 to the shape memory alloy 32. The shape memory alloy 32 will sense the temperature change and thus bend and deform. The bent shape memory alloy 32 can contact the contact plate 34 and make the contact plate 34 drive the feedback rod 33 to move outwards. The user can observe the position state of the feedback rod 33 to know whether the inside of the detection box body 1 has lost temperature and check the reagent state.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A kit for determining the content of D-lactic acid, comprising a detection box body (1), an assembly strip (3) for assembly is arranged on the side of the detection box body (1), a protective cover (2) is arranged above the detection box body (1), and a mixing cylinder (4) for mixing reagents is arranged on the outermost side of the end-side detection box body (1), characterized in that, An auxiliary base (11) is fixedly connected inside the detection box body (1), and a clamping plate (16) is arranged on the upper side of the auxiliary base (11). An adjusting mechanism is arranged inside the auxiliary base (11), and the adjusting mechanism realizes the moving clamping operation of the clamping plate (16) through the gas exchange between the first airbag (7) and the second airbag (8) it includes. A limiting frame (30) is fixedly connected to the inner wall of the detection box body (1), and a feedback mechanism is arranged inside the limiting frame (30). The feedback mechanism realizes the feedback of the temperature inside the detection box body (1) through the change in the position state of the feedback rod (33) it includes.

2. The D-lactic acid content determination kit according to claim 1, wherein: A docking rod (10) is fixedly connected to the lower surface of the protective cover (2). A docking groove (5) adapted to the docking rod (10) is formed on the upper surface of the detection box body (1), and an auxiliary box (6) is fixedly connected below the docking groove (5).

3. The D-lactic acid content determination kit according to claim 2, characterized in that: The adjusting mechanism includes a moving groove (12) formed inside the auxiliary base (11). A sliding block (17) is nested and connected inside the moving groove (12). The upper surface of the sliding block (17) is fixedly connected to the lower surface of the clamping plate (16). A second airbag (8) is fixedly connected between the side of the sliding block (17) and the side wall of the moving groove (12). The first airbag (7) is fixedly connected inside the auxiliary box (6), and a communicating hose (9) is arranged through between the second airbag (8) and the first airbag (7).

4. The D-lactic acid content determination kit according to claim 3, characterized in that: A rotating shaft (14) is rotatably arranged at the center of the clamping plate (16). A limiting plate (15) is fixedly connected to the middle part on the outer side of the rotating shaft (14). A torsion spring (25) is fixedly connected between the upper end side of the limiting plate (15) and the clamping plate (16). A traction rope (18) is wound around the outer side of the rotating shaft (14), and the other end of the traction rope (18) is fixedly connected to the upper surface of the auxiliary base (11).

5. The D-lactic acid content determination kit according to claim 4, characterized in that: The sliding block (17) forms a sliding structure with the moving groove (12) through the second airbag (8). The limiting plate (15) forms a rotating structure with the clamping plate (16) through the rotating shaft (14), and rubber points are arranged on the inner side of the limiting plate (15).

6. The kit for determining the D-lactic acid content according to claim 3, characterized in that: An auxiliary shaft (13) is rotatably connected to the center of the moving groove (12). A turntable (27) is fixedly connected to the outer side of the auxiliary shaft (13). A rotating rod (23) is hinged to the side of the turntable (27). A pull rod (35) is fixedly connected to the side of the sliding block (17), and the inner end of the pull rod (35) is hinged to the other side of the rotating rod (23).

7. A kit for determining the content of D-lactic acid according to claim 6, characterized in that: A button (19) is fixedly connected inside the movable slot (12). A connecting rod (22) is fixedly connected to the side of the auxiliary shaft (13), and a first magnetic block (20) is fixedly connected to the outer end of the connecting rod (22). A limiting rod (24) is nested inside the auxiliary base (11), and a second magnetic block (21) is fixedly connected to one end of the limiting rod (24) close to the first magnetic block (20). A pressing plate (28) is fixedly connected to one end of the second magnetic block (21) close to the button (19). A second spring (29) is fixedly connected between the inner side of the pressing plate (28) and the movable slot (12). A temperature control tube (26) electrically connected to the button (19) is arranged on the upper surface of the auxiliary base (11).

8. The D-lactic acid content determination kit according to claim 1, wherein: The feedback mechanism includes a heat conducting plate (31). The heat conducting plate (31) is nested on the side of the limiting frame (30). A shape memory alloy (32) is nested inside the limiting frame (30). The side of the shape memory alloy (32) is fixedly connected to the inner end of the heat conducting plate (31). A contact plate (34) corresponding to the position of the limiting frame (30) is nested on the front side of the detection box body (1). The contact plate (34) is fixedly connected to the inner end of the feedback rod (33). The feedback rod (33) is nested on the detection box body (1).

9. A determination method of a D-lactic acid content determination kit, applied to a D-lactic acid content determination kit as shown in claim 1, characterized in that: It includes the following steps: S1: After placing the reagent inside the reagent tube, place the reagent tube inside the corresponding detection box body (1). At this time, close the protective cover (2) and the detection box body (1). The second airbag (8) will expand and push the sliding block (17). Moving the sliding block (17) will drive the clamping plates (16) on both sides to slide towards each other, and initially clamp the reagent tube. At the same time, the rotating shaft (14) rotates under the traction of the traction rope (18), and drives the limiting plate (15) to rotate inwards synchronously, so as to further resist the reagent tube, prevent the reagent tube from shifting and shaking, and avoid damage to the reagent tube; S2: During the movement of the sliding block (17), the rotating rod (23) hinged to it is pushed synchronously through the pull rod (35). At this time, the turntable (27) drives the rotating shaft (14) to rotate synchronously. The rotating rotating shaft (14) can drive the first magnetic block (20) to rotate through the connecting rod (22). At this time, the first magnetic block (20) does not adsorb the second magnetic block (21). The pressing plate (28) can slide towards one side of the button (19) under the driving of the elastic force of the second spring (29), so as to press the button (19), enabling the temperature control tube (26) to start and perform temperature control processing. When the temperature control of the temperature control tube (26) fails, the shape memory alloy (32) will sense the temperature change and thus bend and deform. The bent shape memory alloy (32) can resist the contact plate (34) and drive the feedback rod (33) to move outwards. The user can observe the position state of the feedback rod (33) to know whether the inside of the detection box body (1) has lost temperature and check the reagent state; S3: D-lactic acid is converted into pyruvate under the action of D-lactic acid dehydrogenase, and NAD+ is reduced to generate NADH; in order to make this reaction proceed smoothly, another enzyme is added to further decompose pyruvate, and the generated NADH reacts with a specific chromogenic agent to produce a colored substance with a maximum absorption peak at 450 nm. By detecting the increase in the amount of this substance at 450 nm, the content of D-lactic acid can be calculated accordingly.

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