Flow phase mixing mechanism, liquid chromatograph using the mechanism and method

Abstract

The application discloses a flow phase mixing mechanism, a liquid mass spectrometer using the mechanism and a method, and is applied to the technical field of liquid mass spectrometers, and the technical scheme points of the application are as follows: the flow phase mixing mechanism comprises a mixing cylinder; a group of oppositely arranged Laval nozzles for inputting flow phase into the mixing cylinder are fixedly arranged at the top of the mixing cylinder; a first flow control valve for controlling the input rate of the flow phase and a temperature control assembly for controlling the temperature of the flow phase sprayed in the Laval nozzle are fixedly arranged on the Laval nozzle; a flow distribution assembly is fixedly arranged at the top of the mixing cylinder close to the Laval nozzle; and a cross flow mixing assembly and a turbulent flow mixing assembly are respectively fixedly arranged at the bottom of the flow distribution assembly along the vertical direction. The application has the technical effect that the mixing efficiency and mixing effect are good, and the mixing proportion of the flow phase can be accurately controlled.

Description

Technical Field

[0001] This invention relates to the field of liquid chromatography-mass spectrometry (LC-MS) technology, and particularly to a mobile phase mixing mechanism, an LC-MS apparatus using the mechanism, and a method thereof. Background Technology

[0002] Pharmaceutical analysis is mainly used in the pharmaceutical and chemical industries. Liquid chromatography-mass spectrometry (LC-MS) is required for pharmaceutical analysis. LC-MS is mainly used in drug metabolism and pharmacokinetics research, clinical pharmacology research, development and research of natural medicines (traditional Chinese medicine, etc.), newborn screening, identification of proteins and peptides, residue analysis, toxicology analysis, and environmental analysis in industries such as public security, environmental protection, food, tap water, and health and epidemic prevention.

[0003] Currently, Chinese utility model patent CN217404223U discloses a mobile phase mixing device for a liquid chromatography-mass spectrometry (LC-MS) instrument, which includes a tank body. The upper end of the tank body is fixedly connected to a tank cover by bolts. Feed pipes are installed on both the left and right sides of the upper end of the tank cover. The lower ends of the feed pipes penetrate the tank cover and extend into the tank body. The lower ends of the two sets of feed pipes are fixedly connected to a premixing box, and the feed pipes are connected to the premixing box.

[0004] Existing utility models improve mixing efficiency by mixing materials twice. However, on the one hand, mechanical agitation of the mobile phase by a rotating shaft alone is insufficient to achieve high-precision mixing between the mobile phases, especially in situations where the requirements for mobile phase mixing are more stringent, thus affecting the detection and analysis results of liquid chromatography-mass spectrometry (LC-MS). On the other hand, due to the different properties of the mobile phases, the mixing ratio between them needs to be controlled during mixing. Controlling the flow rate of the mobile phase flowing into the premixing tank solely through two solenoid valves is insufficient to achieve precise control of the mixing ratio, thus requiring improvement. Summary of the Invention

[0005] The primary objective of this invention is to provide a mobile phase mixing mechanism, which has the advantages of good mixing efficiency and mixing effect, and can precisely control the mixing ratio of the mobile phase.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a mobile phase mixing mechanism, including a mixing cylinder; a set of Laval nozzles, which are arranged opposite to each other and used to input the mobile phase into the mixing cylinder, are fixedly provided on the top of the mixing cylinder; a first flow control valve for controlling the input rate of the mobile phase and a temperature control component for controlling the temperature of the mobile phase injected into the Laval nozzle are fixedly provided on the Laval nozzle; a flow splitting component is fixedly provided on the top of the mixing cylinder near the top of the Laval nozzle; a cross-flow mixing component and a turbulent flow mixing component are respectively fixedly provided on the bottom of the mixing cylinder along the vertical direction; and a first discharge port is fixedly provided on the bottom of the turbulent flow mixing component.

[0007] The invention is further configured such that: the Laval nozzle is fixedly provided with a storage cavity for storing the mobile phase at the starting end along the flow direction of the mobile phase; the Laval nozzle is provided with an input pipe, a narrow throat pipe and an injection pipe communicating with the storage cavity along the flow direction of the mobile phase; a pressure pump is connected to the storage cavity to increase the pressure of the mobile phase stored in the storage cavity; the mobile phase input port of the storage cavity is provided with a second flow control valve for controlling the mobile phase in the storage cavity; and the first flow control valve is fixedly provided on the input pipe.

[0008] The present invention is further configured such that: the temperature control component includes a first temperature control plate, a second temperature control plate, and a third temperature control plate respectively attached to the input pipe, the narrow throat pipe, and the injection pipe for adjusting the injection temperature of the mobile phase; and a plurality of temperature sensors are fixedly attached to the input pipe, the narrow throat pipe, and the injection pipe.

[0009] The present invention is further configured such that the centerlines of the injection pipes of the two Laval nozzles coincide and the nozzle openings are spaced apart, with the spacing not exceeding 1 / 2 of the diameter of the mixing cylinder and not less than 1 / 4 of the diameter of the mixing cylinder.

[0010] The present invention is further configured such that: the flow splitting component includes a flow splitting cylinder symmetrically and fixedly connected in parallel within the mixing cylinder, and a flow splitting cylinder fixedly connected to the bottom of the flow splitting cylinder for discharging the initially mixed mobile phase into a second discharge port within the cross-flow mixing component, wherein the diameter of the flow splitting cylinder gradually decreases along the vertical direction.

[0011] The present invention is further configured such that: the cross-flow mixing assembly includes a first cross-mixing tube and a second cross-mixing tube arranged in a cross-direction arrangement, the first cross-mixing tube and the second cross-mixing tube are interconnected and each has a third drain port at its bottom, a first arc-shaped guide plate extending into the second cross-mixing tube is tangentially fixed on the first cross-mixing tube, a second arc-shaped guide plate extending into the first cross-mixing tube is tangentially fixed on the second cross-mixing tube, a first mixing shaft is rotatably connected to the center of both the first cross-mixing tube and the second cross-mixing tube, a plurality of first mixing plates are uniformly arranged along the circumferential direction on the first mixing shaft, a second mixing shaft is rotatably connected between the first arc-shaped guide plate and the second arc-shaped guide plate, a plurality of second mixing plates are uniformly fixed on the second mixing shaft, and a driving component for driving the first mixing tube and the first mixing shaft in the second cross-mixing tube to rotate synchronously in the same direction is fixedly connected to the mixing cylinder.

[0012] The present invention is further configured such that: the driving assembly includes a first bevel gear coaxially fixedly connected to the first mixing shaft, a driving motor is fixedly provided at the bottom of the mixing cylinder, and a second bevel gear that cooperates with the first bevel gear is fixedly provided on the rotating shaft of the driving motor.

[0013] The present invention is further configured such that: the turbulent mixing assembly includes a turbulent mixing tube disposed within the mixing cylinder, the turbulent mixing tube being connected to the third drain outlet and the first drain outlet being disposed at the bottom of the turbulent mixing tube; two first mixing shafts respectively penetrate the turbulent mixing tube and the first cross mixing tube, as well as the turbulent mixing tube and the second cross mixing tube; a plurality of mixing rods are uniformly fixed along the circumferential direction on the portion of the first mixing shaft located in the turbulent mixing tube; and the mixing tubes on the two first mixing shafts are arranged at intervals and cross each other at different heights.

[0014] The second objective of this invention is to provide a liquid chromatography-mass spectrometry (LC-MS) instrument with advantages such as good mixing efficiency and mixing effect, and the ability to precisely control the mixing ratio of the mobile phase.

[0015] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a liquid chromatography-mass spectrometry (LC-MS) instrument, which applies the mobile phase mixing mechanism described in any of the above technical solutions.

[0016] The third objective of this invention is to provide a mobile phase mixing method, which has the advantages of good mixing efficiency and mixing effect, and can accurately control the mixing ratio of the mobile phase.

[0017] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a mobile phase mixing method, comprising a mobile phase mixing mechanism according to any of the above-mentioned technical solutions; including:

[0018] Step 1: A certain amount of pressurized mobile phase is sprayed out of the Laval nozzle in a mist or spray form at a set speed and mixed to complete the initial mixing. During the spraying process, the temperature control component controls the temperature of the mobile phase in real time to keep it within the set range and measures the temperature of the mobile phase inside the Laval nozzle.

[0019] Step 2: After initial mixing, the mobile phase is evenly distributed into two groups by the splitting component and simultaneously enters the cross-flow mixing component. The two groups of mobile phases are mixed separately in the cross-flow mixing component, while the mobile phases cross to form a cross flow to achieve further mixing.

[0020] Step 3: After further mixing, the mobile phase enters the turbulent mixing component for further mixing. The mobile phase is stirred in the turbulent mixing component and forms a turbulent flow with constantly changing flow direction to complete the final mixing of the mobile phase. The final mixed mobile phase is discharged from the first drain port.

[0021] In summary, the present invention has the following beneficial effects:

[0022] 1. Two sets of opposing Laval nozzles are installed at the top of the mixing cylinder, and a storage chamber for storing the mobile phase and a pressurizing pump for increasing the pressure of the mobile phase in the storage chamber are installed on the Laval nozzles. After pressurization, the mobile phase is sprayed out from the Laval nozzles in a mist or spray form and mixed. The mobile phase is changed from a whole-body mixture to a mist or spray mixture, which greatly increases the uniformity of the mixing. The first flow control valve and the second flow control valve can accurately control the content of the mobile phase in the storage chamber and the discharge rate of the mobile phase, thereby achieving precise control of the mixing ratio of the mobile phase. A temperature control component is installed on the Laval nozzle. Since the flow rate and temperature of the fluid change when passing through the narrow throat, which affects the temperature of the mobile phase, the temperature control component can ensure that the temperature of the mobile phase discharged through the Laval nozzle is maintained within the set range, avoiding excessive temperature changes that affect the properties of the mobile phase and improving the mixing effect.

[0023] 2. A cross-flow mixing component and a turbulent mixing component are configured. The cross-flow mixing component consists of a first cross-flow mixing pipe and a second cross-flow mixing pipe that are interconnected, and a first arc-shaped guide plate and a second arc-shaped guide plate. When the drive component drives the two first mixing shafts to rotate synchronously in the same direction, the mobile phase, after initial mixing, is mechanically stirred in the first and second cross-flow mixing pipes and rotates in the same direction. Part of the mobile phase will enter the second cross-flow mixing pipe from the first cross-flow mixing pipe through the first arc-shaped guide plate, and so on. A portion of the mobile phase enters the first cross mixing tube from the second cross mixing tube through the second arc-shaped guide plate. The two portions of the mobile phase cross at the middle position and drive the second mixing shaft to rotate. The orderly mixing of the mobile phase improves the mixing effect. Meanwhile, the turbulent mixing component drives the mixing rods that are set at intervals to rotate through two synchronously rotating first mixing shafts in the same direction, thereby generating turbulence at the intersection. The mixing efficiency of the mobile phase is improved by eliminating the need for mixing. The combination of ordered and disordered mixing of the mobile phase ensures better mixing efficiency and mixing effect. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of the overall structure of this embodiment;

[0025] Figure 2 yes Figure 1 Enlarged schematic diagram of part A;

[0026] Figure 3 yes Figure 1 Enlarged diagram of part B;

[0027] Figure 4 yes Figure 1A cross-sectional view of the structure along the CC direction;

[0028] Figure 5 yes Figure 1 A structural cross-sectional view along the DD direction.

[0029] Reference numerals: 1. Mixing cylinder; 2. Laval nozzle; 21. First flow control valve; 22. Storage chamber; 23. Inlet pipe; 24. Narrow throat pipe; 25. Injection pipe; 26. Pressurization pump; 27. Second flow control valve; 3. Temperature control assembly; 31. First temperature control plate; 32. Second temperature control plate; 33. Third temperature control plate; 34. Temperature sensor; 4. Flow splitting assembly; 41. Flow splitting cylinder; 42. Second drain port; 5. Cross-flow mixing assembly; 51. The... 52. A cross-mixing tube; 53. A second cross-mixing tube; 54. A third drain outlet; 55. A first arc-shaped guide plate; 56. A second arc-shaped guide plate; 57. A first mixing shaft; 58. A first mixing plate; 59. A drive assembly; 50. A first bevel gear; 51. A drive motor; 52. A second bevel gear; 53. A second mixing shaft; 54. A second mixing plate; 55. A turbulent mixing assembly; 66. A turbulent mixing tube; 67. A first drain outlet; 68. A mixing rod. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Example 1:

[0032] refer to Figures 1 to 5A mobile phase mixing mechanism includes a fixedly installed mixing cylinder 1. A set of opposing Laval nozzles 2 are fixedly installed on the top of the mixing cylinder 1 for inputting the mobile phase into the mixing cylinder 1. A storage chamber 22 for storing the mobile phase is fixedly installed at the starting end of the Laval nozzle 2 along the flow direction of the mobile phase. Along the flow direction of the mobile phase, the Laval nozzle 2 has an input pipe 23, a narrow throat pipe 24, and an injection pipe 25 communicating with the storage chamber 22. A pressure pump 26 is connected to the storage chamber 22 to increase the pressure of the mobile phase stored in the storage chamber 22. A second flow control valve 27 for controlling the mobile phase in the storage chamber 22 is installed at the mobile phase inlet of the storage chamber 22. Simultaneously, a first flow control valve 21 for controlling the input rate of the mobile phase and a temperature control assembly 3 for controlling the temperature of the mobile phase injected into the Laval nozzle 2 are fixedly installed on the Laval nozzle 2. The first flow control valve 21 is fixedly installed on the input pipe 23, and the second flow control valve 27... The content of the mobile phase stored in the storage chamber 22 can be precisely controlled. The second flow control valve 27 can precisely control the discharge rate of the mobile phase, thereby achieving precise control of the mixing ratio of the mobile phase. After being pressurized, the mobile phase is sprayed out from the Laval nozzle 2 in the form of mist or spray and mixed. The mobile phase changes from overall mixing to mist or spray mixing, which greatly increases the uniformity of mixing. The mixing cylinder 1 is fixedly provided with a flow divider 4 near the top of the Laval nozzle 2. The flow divider 4 can evenly divide the mobile phase after preliminary mixing into two parts. The mixing cylinder 1 is fixedly provided with a cross-flow mixing component 5 and a turbulent mixing component 6 at the bottom of the flow divider 4 along the vertical direction. The mobile phase after passing through the flow divider 4 enters the cross-flow mixing component 5 and the turbulent mixing component 6 in turn for mixing. The bottom of the turbulent mixing component 6 is fixedly provided with a first drain port 62. The mobile phase after mixing is discharged from the mixing cylinder 1 through the first drain port 62.

[0033] refer to Figure 1 and Figure 2Specifically, the temperature control component 3 includes a first temperature control plate 31, a second temperature control plate 32, and a third temperature control plate 33, which are respectively attached to the input pipe 23, the narrow throat pipe 24, and the injection pipe 25 to adjust the injection temperature of the mobile phase. The first temperature control plate 31, the second temperature control plate 32, and the third temperature control plate 33 can adjust the temperature of the input pipe 23, the narrow throat pipe 24, and the injection pipe 25 according to the properties of the mobile phase, so that the temperature of the mobile phase after flowing through can reach the set temperature requirement. Since the flow rate and temperature of the fluid will change when passing through the narrow throat pipe 24, thus affecting the temperature of the mobile phase, the temperature control component 3 can ensure that the temperature of the mobile phase discharged through the Laval nozzle 2 can be kept within the set range, avoiding excessive temperature changes that affect the properties of the mobile phase and improving the mixing effect. Several temperature sensors 34 are attached and fixed on the input pipe 23, the narrow throat pipe 24, and the injection pipe 25. The temperature sensors 34 can measure in real time whether different positions on the Laval nozzle 2 have reached the set temperature to determine whether mixing can be carried out, and can monitor the temperature of the mobile phase. In this embodiment, the centerlines of the injection pipes 25 of the Laval nozzle 2 coincide and the nozzles of the injection pipes 25 are spaced apart. The spacing distance is not higher than 1 / 2 of the diameter of the mixing cylinder 1 and not lower than 1 / 4 of the diameter of the mixing cylinder 1, preferably 1 / 3. The spacing distance can be adjusted according to the properties of the mobile phase and the injection pressure, while ensuring that the mobile phase intersection position of the two Laval nozzles 2 coincides with the central axis of the mixing cylinder 1.

[0034] refer to Figure 1 and Figure 2 Specifically, the flow divider assembly 4 includes flow divider cylinders 41 that are symmetrically and fixedly connected in parallel within the mixing cylinder 1, and a second drain port 42 fixedly connected to the bottom of the flow divider cylinders 41 for discharging the initially mixed mobile phase into the cross-flow mixing assembly 5. The diameter of the flow divider cylinders 41 gradually decreases along the vertical direction. The initially mixed mobile phase automatically falls into the two flow divider cylinders 41, so that the content of the mobile phase in each flow divider cylinder 41 remains basically equal, ensuring the effect of subsequent cross-mixing.

[0035] refer to Figure 1 and Figure 4Specifically, the cross-flow mixing assembly 5 includes a first cross-flow mixing tube 51 and a second cross-flow mixing tube 52 arranged in a cross-flow configuration. The first cross-flow mixing tube 51 and the second cross-flow mixing tube 52 are interconnected and each has a third drain port 53 at its bottom. Each of the first drain port 62, the second drain port 42, and the third drain port 53 is equipped with a switch valve to control the drain flow. A first arc-shaped guide plate 54 extending into the second cross-flow mixing tube 52 is tangentially fixed to the first cross-flow mixing tube 51. A second arc-shaped guide plate 55 extending into the first cross-mixing pipe 51 is tangentially fixed on the second cross-mixing pipe 52. A first mixing shaft 56 is rotatably connected to the center of both the first cross-mixing pipe 51 and the second cross-mixing pipe 52. A plurality of first mixing plates 57 are evenly arranged along the circumferential direction on the first mixing shaft 56, with 4-6 first mixing plates 57 arranged. A second mixing plate 55 is rotatably connected between the first arc-shaped guide plate 54 and the second arc-shaped guide plate 55. A uniform shaft 59 is provided, and several second mixing plates 510 are uniformly fixed on the second mixing shaft 59. Similarly, 4-6 second mixing plates 510 are provided on the first mixing plate 57. A drive assembly 58 is fixedly connected to the mixing cylinder 1 to drive the first mixing shaft 56 in the first cross mixing tube 51 and the second cross mixing tube 52 to rotate synchronously in the same direction. When the drive assembly 58 drives the two first mixing shafts 56 to rotate synchronously in the same direction, the mobile phase after preliminary mixing is mechanically stirred in the first cross mixing tube 51 and the second cross mixing tube 52 and rotates in the same direction. Part of the mobile phase will enter the second cross mixing tube 52 from the first cross mixing tube 51 through the first arc-shaped guide plate 54. Similarly, part of the mobile phase will enter the first cross mixing tube 51 from the second cross mixing tube 52 through the second arc-shaped guide plate 55. The two parts of the mobile phase cross at the middle position and drive the second mixing shaft 59 to rotate. The mobile phase mixing effect is improved by orderly mixing of the mobile phase.

[0036] refer to Figure 1 and Figure 3 Specifically, the drive assembly 58 includes a first bevel gear 581 coaxially fixedly connected to two first mixing shafts 56, a drive motor 582 fixedly mounted at the bottom of the mixing cylinder 1, and a second bevel gear 583 cooperating with the first bevel gear 581 fixedly mounted on the rotating shaft of the drive motor 582. There are two of each of the first bevel gear 581 and the second bevel gear 583. The two second bevel gears 583 are connected by a connecting shaft to achieve synchronous and co-rotation of the two second bevel gears 583, thereby driving the two first bevel gears 581 to rotate synchronously and co-rotate, and indirectly driving the two first mixing shafts 56 to rotate synchronously and co-rotate.

[0037] refer to Figure 1 and Figure 5Specifically, the turbulent mixing component 6 includes a turbulent mixing tube 61 disposed inside the mixing cylinder 1. The turbulent mixing tube 61 is connected to the third drain port 53, and the first drain port 62 is disposed at the bottom of the turbulent mixing tube 61. Two first mixing shafts 56 pass through the turbulent mixing tube 61 and the first cross mixing tube 51, as well as the turbulent mixing tube 61 and the second cross mixing tube 52, respectively. A plurality of mixing rods 63 are uniformly fixed along the circumferential direction on the part of the first mixing shaft 56 located in the turbulent mixing tube 61. The mixing tubes on the two first mixing shafts 56 are arranged at intervals and cross each other and are located at different heights. Since the mixing rods 63 on the two first mixing shafts 56 partially overlap, the first mixing shafts 56 drive the spaced and cross-arranged mixing rods 63 to rotate, thereby generating turbulence at the intersection. The mixing efficiency of the mobile phase is improved by eliminating the need for mixing of the mobile phase. The combination of ordered and disordered mixing of the mobile phase ensures better mixing efficiency and mixing effect.

[0038] Example 2:

[0039] The liquid chromatography-mass spectrometry (LC-MS) instrument uses the mobile phase mixing mechanism shown in Example 1.

[0040] Example 3:

[0041] The mobile phase mixing method, using the mobile phase mixing mechanism of Example 1, includes:

[0042] Step 1: A certain amount of pressurized mobile phase is sprayed out of the Laval nozzle 2 at a set speed in the form of mist or spray and mixed to complete the initial mixing. During the spraying process, the temperature control component 3 controls the temperature of the mobile phase in real time to keep it within the set range and measures the temperature of the mobile phase inside the Laval nozzle 2.

[0043] Step 2: After initial mixing, the mobile phase is evenly distributed into two groups by the flow splitter 4 and simultaneously enters the cross-flow mixing component 5. The two groups of mobile phases are mixed separately in the cross-flow mixing component 5, while the mobile phases cross to form a cross flow to achieve further mixing.

[0044] Step 3: After further mixing, the mobile phase enters the turbulent mixing component 6 for further mixing. The mobile phase is stirred in the turbulent mixing component 6 and forms a turbulent flow with constantly changing flow direction to complete the final mixing of the mobile phase. The final mixed mobile phase is discharged from the first drain port 62.

[0045] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make inventive modifications to this embodiment as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A mobile phase mixing mechanism, comprising a mixing cylinder (1); characterized in that, The top of the mixing cylinder (1) is fixedly provided with a set of opposing Laval nozzles (2) for inputting the mobile phase into the mixing cylinder (1). The Laval nozzle (2) is fixedly provided with a first flow control valve (21) for controlling the input rate of the mobile phase and a temperature control component (3) for controlling the temperature of the mobile phase injected into the Laval nozzle (2). The top of the mixing cylinder (1) near the top of the Laval nozzle (2) is fixedly provided with a flow splitting component (4). The bottom of the mixing cylinder (1) along the vertical direction is respectively fixedly provided with a cross-flow mixing component (5) and a turbulent mixing component (6). The bottom of the turbulent mixing component (6) is fixedly provided with a first drain port (62). The flow divider assembly (4) includes a flow divider (41) symmetrically and fixedly connected in parallel within the mixing cylinder (1) and a second drain port (42) fixedly connected to the bottom of the flow divider (41) for discharging the initially mixed mobile phase into the cross-flow mixing assembly (5). The diameter of the flow divider (41) gradually decreases along the vertical direction. The cross-flow mixing assembly (5) includes a first cross-flow mixing tube (51) and a second cross-flow mixing tube (52) arranged in a cross-flow configuration. The first cross-flow mixing tube (51) and the second cross-flow mixing tube (52) are interconnected and each has a third drain port (53) at its bottom. A first arc-shaped guide plate (54) extending into the second cross-flow mixing tube (52) is tangentially fixed on the first cross-flow mixing tube (51), and a second arc-shaped guide plate (55) extending into the first cross-flow mixing tube (51) is tangentially fixed on the second cross-flow mixing tube (52). The first cross-flow mixing tube (51) and the second cross-flow mixing tube (52) are connected in a cross-flow configuration. A first mixing shaft (56) is rotatably connected to the center of each mixing tube (52). A plurality of first mixing plates (57) are uniformly arranged on the first mixing shaft (56) along the circumferential direction. A second mixing shaft (59) is rotatably connected between the first arc-shaped guide plate (54) and the second arc-shaped guide plate (55). A plurality of second mixing plates (510) are uniformly fixed on the second mixing shaft (59). A driving assembly (58) is fixedly connected to the mixing cylinder (1) for driving the first mixing shaft (56) in the first cross mixing tube (51) and the second cross mixing tube (52) to rotate synchronously in the same direction. The drive assembly (58) includes a first bevel gear (581) coaxially fixedly connected to the first mixing shaft (56), a drive motor (582) fixedly provided at the bottom of the mixing cylinder (1), and a second bevel gear (583) cooperating with the first bevel gear (581) fixedly provided on the rotating shaft of the drive motor (582). The turbulent mixing assembly (6) includes a turbulent mixing tube (61) disposed in the mixing cylinder (1). The turbulent mixing tube (61) is connected to the third drain port (53), and the first drain port (62) is disposed at the bottom of the turbulent mixing tube (61). Two first mixing shafts (56) pass through the turbulent mixing tube (61) and the first cross mixing tube (51), as well as the turbulent mixing tube (61) and the second cross mixing tube (52), respectively. A plurality of mixing rods (63) are uniformly fixed along the circumferential direction on the part of the first mixing shaft (56) located in the turbulent mixing tube (61). The mixing rods (63) on the two first mixing shafts (56) are arranged at intervals and cross each other and are located at different heights.

2. The mobile phase mixing mechanism according to claim 1, characterized in that, The Laval nozzle (2) is fixedly provided with a storage chamber (22) for storing the mobile phase at the starting end along the flow direction of the mobile phase. Along the flow direction of the mobile phase, the Laval nozzle (2) is provided with an input pipe (23), a narrow throat pipe (24), and an injection pipe (25) connected to the storage chamber (22). The storage chamber (22) is externally connected to a pressure pump (26) to increase the pressure of the mobile phase stored in the storage chamber (22). The mobile phase input port of the storage chamber (22) is provided with a second flow control valve (27) for controlling the mobile phase in the storage chamber (22). The first flow control valve (21) is fixedly installed on the input pipe (23).

3. The mobile phase mixing mechanism according to claim 2, characterized in that, The temperature control assembly (3) includes a first temperature control plate (31), a second temperature control plate (32), and a third temperature control plate (33) respectively attached to the input pipe (23), the narrow throat pipe (24), and the injection pipe (25) for adjusting the injection temperature of the mobile phase. Several temperature sensors (34) are attached and fixedly disposed on the input pipe (23), the narrow throat pipe (24), and the injection pipe (25).

4. The mobile phase mixing mechanism according to claim 2, characterized in that, The centerlines of the injection pipes (25) of the two Laval nozzles (2) coincide and the nozzles of the injection pipes (25) are spaced apart, with the spacing not higher than 1 / 2 and not lower than 1 / 4 of the diameter of the mixing cylinder (1).

5. A liquid chromatography-mass spectrometry (LC-MS) instrument, employing the mobile phase mixing mechanism described in any one of claims 1-4.

6. A method for homogenizing a mobile phase, employing the mobile phase homogenizing mechanism described in any one of claims 1-4; characterized in that, include: Step 1: A certain amount of pressurized mobile phase is sprayed out of the Laval nozzle (2) at a set speed in the form of mist or spray and mixed to complete the initial mixing. During the spraying process, the temperature control component (3) controls the temperature of the mobile phase in real time to keep it within the set range and measures the temperature of the mobile phase in the Laval nozzle (2). Step 2: After initial mixing, the mobile phase is evenly distributed into two groups by the splitting component (4) and simultaneously enters the cross-flow mixing component (5). The two groups of mobile phases are mixed separately in the cross-flow mixing component (5) while the mobile phases cross to form a cross-flow to achieve further mixing. Step 3: After further mixing, the mobile phase enters the turbulent mixing component (6) for mixing. The mobile phase is stirred in the turbulent mixing component (6) and forms a turbulent flow with constantly changing flow direction to complete the final mixing of the mobile phase. The mobile phase after final mixing is discharged from the first drain port (62).

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