Flow cell with double axial tapered cavity and irregular cross section

Abstract

The present invention discloses a flow cell with a double-axial tapered cavity and a gradient irregular cross section. The key points of the technical solution include a main body and two light-transmitting sheets. An optical channel running through the main body is provided in the main body, and the two light-transmitting sheets respectively block the two ends of the optical channel; two liquid channels are also provided on the main body, and the two ends of each liquid channel are respectively connected to the optical channel and the outside of the main body; the channel openings at both ends of the optical channel are rectangular and circular respectively; the long side of the rectangular channel opening is greater than the diameter of the circular channel opening, and the short side of the rectangular channel opening is smaller than the diameter of the circular channel opening; the cross section of the optical channel gradually transitions from rectangular to circular. The present invention optimizes the shape of the optical channel based on the diffusion law of light, subtracts unnecessary pool volume without losing the optical path, and reduces peak expansion. Increasing the length of the optical channel in the present invention can improve the detection sensitivity of the flow cell while ensuring a high peak resolution.

Description

Technical Field

[0001] The present invention relates to the technical field of optical instrument analysis, and more particularly to a double-axial tapered cavity flow cell with a gradient irregular cross section. Background Art

[0002] Flow cells are commonly used in optical detection instruments to measure the optical properties of liquid samples flowing through them. Optical analytical instruments that measure the properties and concentration of substances in liquid samples in flow cells are commonly used in liquid chromatography, capillary electrochromatography, and capillary electrophoresis. Optical analytical instruments that measure the absorbance of ultraviolet (UV) and visible light (Vis) by liquid samples in flow cells are commonly used in chromatographic separation techniques.

[0003] Chinese patent CN107667284A discloses an optical flow cell for an optical measuring device, which includes an input light guide, an output light guide and a holder. The holder has a through hole for receiving a liquid sample flow, the through hole wall is vertical, and the input light guide and the output light guide are both mounted on the holder. Light (composite light or monochromatic light) used to analyze the liquid sample is introduced into the through hole by the input light guide, a portion of the light is absorbed by the liquid sample in the through hole, and the remaining light is led out of the through hole by the output light guide. In actual use, the light led out by the output light guide will be incident on a photosensitive element, which will convert it into an electrical signal. The electrical signal is then sent to an electronic system for amplification and processing to output the optical properties of the liquid sample. In this patent, the window of the light input through hole is the same size as the window of the light output through hole.

[0004] The volume inside the through hole of the above-mentioned patent is the cell volume of the flow cell, and the cell volume is the main factor affecting the detection sensitivity and peak resolution. When the input light guide and the output light guide remain unchanged, the larger the aperture of the through hole, the larger the cell volume, the larger the optical path will be, and the photosensitive element will obtain a larger light intensity, and the detection sensitivity will be relatively high. The smaller the aperture of the through hole, the smaller the optical path, but because the cell volume is smaller at this time, the diffusion of light in the through hole is smaller, and the peak resolution will be higher. In other words, from the perspective of improving detection sensitivity, the through hole aperture should be as large as possible to increase the optical path, but this will cause the cell volume to expand and cause peak expansion; from the perspective of peak resolution, the through hole aperture should be as small as possible to reduce the cell volume and reduce peak expansion, but this will cause the optical path to be reduced. Improving detection sensitivity and improving peak resolution are actually two contradictory requirements.

[0005] The present invention aims to improve the structure of the flow cell to obtain a higher light intensity with a smaller cell volume, thereby improving the detection sensitivity of the flow cell while ensuring a higher peak resolution. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention provides a flow cell with a biaxially tapered cavity and a gradient profile. This cell optimizes the shape of the optical channel based on the laws of light diffusion, eliminating unnecessary cell volume and reducing peak spread without sacrificing optical path length. Increasing the length of the optical channel improves the flow cell's detection sensitivity while maintaining high peak resolution.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a flow cell with a double-axial tapered cavity and a gradient irregular cross-section, comprising a main body and two light-transmitting sheets, wherein an optical channel running through the main body is provided in the main body, and the two light-transmitting sheets respectively block the two ends of the optical channel; two liquid channels are also provided on the main body, and the two ends of each liquid channel are respectively connected to the optical channel and the outside of the main body; the channel openings at the two ends of the optical channel are rectangular and circular, respectively, and the line connecting the center of the rectangular channel opening and the center of the circular channel opening is perpendicular to the plane where the rectangular channel opening and the plane where the circular channel opening are located; the long side of the rectangular channel opening is greater than the diameter of the circular channel opening, and the short side of the rectangular channel opening is smaller than the diameter of the circular channel opening; the cross-section of the optical channel gradually transitions from rectangular to circular.

[0008] By adopting the above technical solution, the shape of the optical channel is optimized according to the law of light diffusion, eliminating unnecessary cell volume and reducing peak spread without sacrificing optical path length. Increasing the length of the optical channel in the present invention can improve the detection sensitivity of the flow cell while maintaining high peak resolution.

[0009] The present invention is further configured such that: the areas of all cross sections of the optical channel are equal.

[0010] By adopting the above technical solution, the liquid sample flows in a laminar state within the optical channel, effectively preventing disturbances in the optical channel that could affect the detection results. The present invention can be used not only when the optical channel is filled with stagnant liquid sample, but also when the optical channel is filled with flowing liquid sample.

[0011] The present invention is further configured such that: the optical channel is processed by wire-cutting.

[0012] By adopting the above technical solution, the processing accuracy of the optical channel can be improved.

[0013] The present invention is further configured such that: the rectangular channel opening is a monochromatic light inlet, and the circular channel opening is a monochromatic light outlet.

[0014] By adopting the above technical solution, in the optical path of the spectroscopic monochromator, the rectangular channel port serves as the entrance for monochromatic light, which is equivalent to the shape of the slit light spot after the diffraction grating is split. Compared with the circular light inlet of the same area on the conventional flow cell, the monochromatic light introduction area is larger.

[0015] The present invention is further configured such that: the circular channel opening is a composite light inlet, and the rectangular channel opening is a composite light outlet.

[0016] By adopting the above technical solution, in the optical path of the polychromator, the rectangular channel port is used as the composite light outlet, and the shape of the composite light spot is trimmed, which is more conducive to imaging at the slit of the optical path outlet after the polychromator, disperses the incident light spot of the diffraction grating of the element, and improves the optical path performance.

[0017] The present invention is further configured to include two pressing members, both of which are detachably connected to the main body, and two light-transmitting sheets are respectively clamped between the two pressing members and the main body; and each pressing member is provided with a light-transmitting through hole.

[0018] By adopting the above technical solution, the light-transmitting sheet is detachably connected to the main body through the pressing piece.

[0019] The present invention is further configured as follows: two mounting grooves are provided on the main body, the two mounting grooves are respectively connected to the two channel openings of the optical channel, and the two light-transmitting sheets are respectively located in the two mounting grooves; the two pressing parts are respectively threadedly connected to the groove walls of the two mounting grooves and press against the two light-transmitting sheets.

[0020] By adopting the above technical solution, the pressing piece is threadedly connected to the main body, which facilitates the detachable connection between the pressing piece and the main body.

[0021] The present invention is further configured to include two first sealing pads, which are respectively located between the two light-transmitting sheets and the main body; and each first sealing pad is provided with a first light-transmitting hole.

[0022] By adopting the above technical solution, the provision of the first sealing gasket can effectively increase the sealing between the light-transmitting sheet and the main body, and reduce the possibility of leakage of the liquid sample from the optical channel.

[0023] The present invention is further configured to include two second sealing pads, each corresponding to two light-transmitting sheets; each second sealing pad is located between its corresponding light-transmitting sheet and the pressing member, and each second sealing pad is provided with a second light-transmitting hole.

[0024] By adopting the above technical solution, the provision of the second sealing gasket can effectively increase the sealing between the light-transmitting sheet and the main body, and reduce the possibility of leakage of the liquid sample from the optical channel.

[0025] The present invention is further configured such that: an end of each liquid channel away from the optical channel is provided with an internal thread.

[0026] By adopting the above technical solution, other components required for detection can be easily connected to the two liquid channels.

[0027] In summary, the present invention has the following beneficial effects compared to the prior art:

[0028] 1. The present invention optimizes the shape of the optical channel based on the diffusion law of light, reducing unnecessary cell volume and peak spread without sacrificing optical path length. Increasing the length of the optical channel in the present invention can improve the detection sensitivity of the flow cell while ensuring high peak resolution.

[0029] 2. In the optical path of the spectroscopic monochromator, the rectangular channel port serves as the entrance for monochromatic light, which is equivalent to the shape of the slit light spot after the diffraction grating splits the light. Compared with the circular light inlet of the same area on the conventional flow cell, the monochromatic light introduction area is larger.

[0030] 3. In the optical path of the polychromator, the rectangular channel port is used as the composite light outlet to trim the shape of the composite light spot, which is more conducive to imaging at the slit of the optical path outlet after the polychromator, disperses the incident light spot of the diffraction grating of the element, and improves the optical path performance.

[0031] 4. The present invention can be used not only when the optical channel is filled with stagnant liquid samples, but also when the optical channel is filled with flowing liquid samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is an exploded schematic diagram of the structure of this embodiment;

[0033] Figure 2 It is a front view of the main body in this embodiment;

[0034] Figure 3 for Figure 2 Rotated sectional view in the A direction;

[0035] Figure 4 for Figure 2 Cross-sectional view in the X direction;

[0036] Figure 5 for Figure 2 Cross-sectional view in the Y direction.

[0037] In the figure: 1. Main body; 11. Optical channel; 111. Rectangular channel opening; 112. Circular channel opening; a1. X-axis inclination angle; a2. Y-axis inclination angle; 12. Liquid channel; 13. Mounting groove; 14. Mounting hole; 2. Translucent sheet; 3. Pressing member; 31. Translucent through hole; 4. First sealing gasket; 41. First translucent hole; 5. Second sealing gasket; 51. Second translucent hole. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the invention.

[0039] It should be noted that the terms "center", "up", "down", "horizontal", "left", "right", "front", "back", "lateral", "longitudinal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] Example

[0041] like Figure 1-3 The figure shows the basic structure of a preferred embodiment of the present invention, a biaxially tapered cavity flow cell with a gradient cross-section and a special shape. The cell comprises a main body 1 and two light-transmitting sheets 2. An optical channel 11 is provided within the main body 1, extending through the main body 1, and the two light-transmitting sheets 2 respectively block the ends of the optical channel 11. The main body 1 is also provided with two liquid channels 12, each of which is connected to the optical channel 11 and the outside of the main body 1 at both ends. In this embodiment, the two liquid channels 12 are connected to the ends of the optical channel 11. The channel openings at both ends of the optical channel 11 are rectangular and circular, respectively. The line connecting the center of the rectangular channel opening 111 and the center of the circular channel opening 112 is perpendicular to both the planes containing the rectangular channel opening 111 and the plane containing the circular channel opening 112. The long side of the rectangular channel opening 111 is greater than the diameter of the circular channel opening 112, and the short side of the rectangular channel opening 111 is smaller than the diameter of the circular channel opening 112. The cross-section of the optical channel 11 gradually transitions from rectangular to circular.

[0042] In this embodiment, among all planes tangent to the edge of the circular channel opening 112, the angle between the two planes where the two short sides of the rectangular channel opening 111 are located is the Y-direction inclination angle a2; among all planes tangent to the edge of the circular channel opening 112, the angle between the two planes where the two long sides of the rectangular channel opening 111 are located is the X-direction inclination angle a1.

[0043] If the light diffuses in a direction parallel to the short side of the rectangular channel opening 111, and the diffusion angle is less than the X-direction inclination angle a1, the light is introduced into the optical channel 11 from the rectangular channel opening 111; if the light diffuses in a direction parallel to the long side of the rectangular channel opening 111, and the diffusion angle is less than the Y-direction inclination angle a2, the light is introduced into the optical channel 11 from the circular channel opening 112. In this embodiment, the inner wall of the optical channel 11 has an X-direction inclination angle a1 and a Y-direction inclination angle a2 in the short side and long side directions of the rectangular channel opening 111, respectively, so that when light diffuses in the optical channel 11, it is not easy to hit the inner wall of the optical channel 11, effectively reducing the adverse effect of the refracted light generated by the light hitting the inner wall of the optical channel 11 on the detection. In this embodiment, the shape of the optical channel 11 is optimized according to the diffusion law of light, and unnecessary pool volume is subtracted without losing the optical path, thereby reducing peak expansion. Increasing the length of the optical channel 11 in this embodiment can achieve an improvement in the detection sensitivity of the flow cell while ensuring a high peak resolution.

[0044] Specifically, in this embodiment, the X-direction tilt angle a1 and the Y-direction tilt angle a2 are the same in magnitude.

[0045] Specifically, in this embodiment, the cross-sections of the optical channel 11 are all of equal size, allowing the liquid sample to flow in a laminar state within the optical channel 11. This effectively prevents disturbances in the optical channel 11 that could affect the test results. Therefore, this embodiment can be used not only when the optical channel 11 is filled with stagnant liquid sample, but also when the optical channel 11 is filled with flowing liquid sample.

[0046] Specifically, in this embodiment, the short side of the rectangular channel opening 111 is 0.6 mm, the long side is 1.8 mm, the diameter of the circular channel opening 112 is 1.2 mm, and the distance from the rectangular channel opening 111 to the circular channel opening 112 is 10 mm. The optimal size of a conventional circular hole flow cell is a hole diameter of 1.2 mm and a length of 10 mm. The cell volume of the optical channel 11 in this embodiment is 11.3 , which is consistent with the optimal volume of a conventional circular hole flow cell. When the optical channel 11 of this embodiment is used with a flowing liquid sample filled therein, the pressure of the liquid sample can reach 10 MPa.

[0047] Specifically, the outer contour of this embodiment is a rectangular parallelepiped, which can be machined using a combination of milling and turning. The optical channel 11 is machined using wire-cut machining to achieve higher precision. To meet the requirements of the wire-cut machining process, the rectangular channel opening 111 can be appropriately rounded. The main body 1 can be made of any conductive material.

[0048] like Figure 4As shown, when this embodiment is installed in the optical path of a spectroscopic monochromator, the diffraction grating, the monochromator's dispersing element, transmits the split monochromatic light through a rectangular channel opening 111 into the optical channel 11. The monochromatic light diffuses within an X-axis inclination angle a1, preventing it from striking the inner wall of the optical channel 11, which could adversely affect detection due to refracted light. Furthermore, the monochromatic light split by the diffraction grating forms a slit spot, which is shaped similarly to the rectangular channel opening 111. Compared to a circular light inlet of the same area on a conventional flow cell, this embodiment provides a larger area for monochromatic light entry.

[0049] like Figure 5 As shown, when this embodiment is installed in the optical path of a polychromator, circular channel opening 112 is positioned near the UV-visible light source. Composite light focused by the lens enters optical channel 11 through circular channel opening 112. The composite light diffuses within a Y-axis angle a2, preventing it from striking the inner wall of optical channel 11, which could adversely affect detection due to refracted light. Rectangular channel opening 111, serving as the composite light outlet, shapes the composite light spot, facilitating imaging at the narrow exit slit of the polychromator's rear optical path, dispersing the incident light spot from the diffraction grating, and improving optical path performance.

[0050] Specifically, this embodiment further includes two pressing members 3, each of which is provided with a light-transmitting through-hole 31. The main body 1 is also provided with two mounting slots 13, each communicating with the two openings of the optical channel 11. The two light-transmitting sheets 2 are positioned within the two mounting slots 13. The two pressing members 3 are threadedly connected to the walls of the two mounting slots 13, respectively, and press against the two light-transmitting sheets 2. The light-transmitting through-hole 31 is larger than the cross-section of either opening of the optical channel 11 to prevent the pressing members 3 from obstructing the optical path.

[0051] Specifically, this embodiment further includes two first sealing gaskets 4 and two second sealing gaskets 5. The two first sealing gaskets 4 are respectively located between the two light-transmitting sheets 2 and the main body 1; each first sealing gasket 4 is provided with a first light-transmitting hole 41. The two second sealing gaskets 5 correspond to the two light-transmitting sheets 2; each second sealing gasket 5 is respectively located between its corresponding light-transmitting sheet 2 and the pressing member 3, and each second sealing gasket 5 is provided with a second light-transmitting hole 51. The provision of the first sealing gasket 4 and the second sealing gasket 5 can effectively increase the sealing between the light-transmitting sheet 2 and the main body 1, reducing the possibility of liquid sample leakage from the optical channel 11. The first light-transmitting hole 41 and the second light-transmitting hole 51 are both larger than the cross-section of any channel opening of the optical channel 11, so as to prevent the first sealing gasket 4 and the second sealing gasket 5 from blocking the optical path.

[0052] Specifically, each liquid channel 12 has an internal thread at one end away from the optical channel 11 to facilitate connection with other components required for detection. In this embodiment, each liquid channel 12 has a liquid connector threadedly connected at one end away from the optical channel 11.

[0053] Specifically, the main body 1 is further provided with a mounting hole 14 for connecting with other components required for detection, and the mounting hole 14 is a threaded hole.

[0054] In summary, this embodiment optimizes the shape of the optical channel 11 according to the diffusion law of light, subtracts unnecessary pool volume without losing the optical path, and reduces peak expansion. Increasing the length of the optical channel 11 in this embodiment can improve the detection sensitivity of the flow cell while ensuring a higher peak resolution. In the optical path of the spectroscopic monochromator, the rectangular channel opening 111 serves as the entrance of monochromatic light, and the shape of the slit light spot after the diffraction grating is comparable to that of the circular light inlet of the same area on a conventional flow cell, and the monochromatic light introduction area is larger. In the optical path of the polychromator, the rectangular channel opening 111 serves as the exit of the composite light, and the shape of the composite light spot is trimmed, which is more conducive to imaging at the slit of the optical path exit after the polychromator, dispersing the incident light spot of the diffraction grating of the element, and improving the performance of the optical path. In addition, this embodiment can be used not only when the optical channel 11 is filled with stagnant liquid samples, but also when the optical channel 11 is filled with flowing liquid samples.

[0055] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A flow cell with a double-axial tapered cavity and a gradient cross-section, characterized by: The invention comprises a main body (1) and two light-transmitting sheets (2), wherein an optical channel (11) penetrating the main body (1) is provided in the main body (1), and the two light-transmitting sheets (2) respectively block the two ends of the optical channel (11); two liquid channels (12) are also provided on the main body (1), and the two ends of each liquid channel (12) are respectively connected to the optical channel (11) and the outside of the main body (1); the channel openings at the two ends of the optical channel (11) are rectangular and circular, respectively, and the line connecting the center of the rectangular channel opening (111) and the center of the circular channel opening (112) is perpendicular to the plane where the rectangular channel opening (111) and the plane where the circular channel opening (112) are located; the long side of the rectangular channel opening (111) is greater than the diameter of the circular channel opening (112), and the short side of the rectangular channel opening (111) is smaller than the diameter of the circular channel opening (112); the cross section of the optical channel (11) gradually transitions from rectangular to circular; Among all planes tangent to the edge of the circular channel opening (112), the angle between the two planes where the two short sides of the rectangular channel opening (111) are located is the Y-direction inclination angle a2; among all planes tangent to the edge of the circular channel opening (112), the angle between the two planes where the two long sides of the rectangular channel opening (111) are located is the X-direction inclination angle a1; The X-direction inclination angle a1 and the Y-direction inclination angle a2 are the same in magnitude.

2. The cross-sectional gradient biaxial tapered cavity flow cell according to claim 1, characterized in that: The short side of the rectangular channel opening (111) is 0.6 mm, the long side is 1.8 mm, the diameter of the circular channel opening (112) is 1.2 mm, and the distance from the rectangular channel opening (111) to the circular channel opening (112) is 10 mm.

3. The flow cell with a double-axial tapered cavity and a gradient cross-section according to any one of claims 1 to 2, characterized in that: The rectangular channel opening (111) is a monochromatic light inlet, and the circular channel opening (112) is a monochromatic light outlet.

4. The flow cell with a double-axial tapered cavity having a gradient cross-section according to any one of claims 1 to 2, characterized in that: The circular channel opening (112) is a composite light inlet, and the rectangular channel opening (111) is a composite light outlet.

5. The flow cell with a double-axial tapered cavity having a gradient cross-section according to any one of claims 1 to 2, characterized in that: The optical channel (11) is processed by wire-cutting.

6. The flow cell with a double-axial tapered cavity and a gradient cross-section according to any one of claims 1-2, characterized in that: It also includes two pressing members (3), both of which are detachably connected to the main body (1), and two light-transmitting sheets (2) are respectively clamped between the two pressing members (3) and the main body (1); each pressing member (3) is provided with a light-transmitting through hole (31).

7. The flow cell with a double-axial tapered cavity and a gradient cross-section according to claim 6, characterized in that: The main body (1) is further provided with two mounting grooves (13), the two mounting grooves (13) being respectively connected to the two channel openings of the optical channel (11), and the two light-transmitting sheets (2) being respectively located in the two mounting grooves (13); the two pressing members (3) being respectively threadedly connected to the groove walls of the two mounting grooves (13) and pressing against the two light-transmitting sheets (2).

8. The flow cell with a double-axial tapered cavity and a gradient cross-section according to claim 7, characterized in that: It also includes two first sealing pads (4), which are respectively located between the two light-transmitting sheets (2) and the main body (1); each first sealing pad (4) is provided with a first light-transmitting hole (41).

9. The flow cell with a double-axial tapered cavity and a gradient cross-section according to claim 8, characterized in that: It also includes two second sealing pads (5), the two second sealing pads (5) corresponding to the two light-transmitting sheets (2) respectively; each second sealing pad (5) is located between its corresponding light-transmitting sheet (2) and the pressing member (3), and each second sealing pad (5) is provided with a second light-transmitting hole (51).

10. The flow cell with a double-axial tapered cavity and a gradient cross-section according to any one of claims 1-2, characterized in that: An end of each liquid channel (12) facing away from the optical channel (11) is provided with an internal thread.

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