guard column cartridge

Abstract

The application relates to the field of liquid chromatography, in particular to a guard column core which comprises an upper sealing body, a lower sealing body, a sealing pipe and a cap body; the upper sealing body and the lower sealing body are used to seal the two end openings of the sealing pipe; the upper sealing body is provided with a first opening, the lower sealing body is provided with a second opening, and a first sieve plate is embedded in the second opening; the cap body is provided with a third opening, a second sieve plate is embedded in the third opening, and the cap body is threadedly connected with the upper sealing body so that the lower end of the second sieve plate extends into the first opening. The column core provided by the application has the advantages of small size and the ability of conveniently replacing the filler, and effectively reduces the experimental and detection cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of liquid chromatography, in particular to a guard column cartridge. BACKGROUND

[0002] In liquid chromatography experiments, a guard column is usually used to protect the chromatographic packing, so as to avoid the enrichment of impurities near the inlet end of the chromatographic column, which ultimately leads to the scrap of the chromatographic column. The effect of the guard column on the chromatographic packing is mainly realized by the cartridge set in its interior. There is sufficient evidence to prove that the cartridge as part of the column external volume, reducing its volume can effectively improve the precision and accuracy of detection. Therefore, the existing cartridge is gradually improved towards miniaturization. However, the smaller the cartridge is, the more difficult it is to disassemble, which makes it difficult to replace the packing inside the cartridge, increasing the experimental cost. For example, US5338448A, US5863428A, US20220196613A1, etc., the structure usually includes an outer flanged ring and an inner flanged ring arranged in each other, and a guard disk material arranged between the two. However, it is almost impossible to safely disassemble due to this kind of nested sealing arrangement. There are also small chromatographic columns on the market composed of an upper cap, a lower cap and a central stainless steel tube, such as the 2.1# and 3.0# cartridges sold by Agilent. Although the upper cap and the lower cap are respectively installed on the axial two sides of the stainless steel tube to allow the user to disassemble either end to replace the packing, in order to ensure the sealing connection between the lower cap, the lower cap and the stainless steel tube, the upper cap and the lower cap are pressed into the two ends of the stainless steel tube by interference fit, and the small overall volume and small force area make the gap between the upper cap and the lower cap almost closed, which makes it almost impossible to disassemble in the actual use process. SUMMARY

[0003] In order to overcome the defects of the prior art, the technical problem to be solved by the present application is to provide a guard column cartridge which is easy to disassemble and replace the packing.

[0004] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: a guard column cartridge, comprising an upper seal body, a lower seal body, a sealing tube and a cap body;

[0005] The upper seal body and the lower seal body are used to close the two end openings of the sealing tube;

[0006] The upper seal body is provided with a first opening, and the lower seal body is provided with a second opening, and a first sieve plate is embedded in the second opening;

[0007] The cap is provided with a third opening, and a second sieve plate is embedded in the third opening; the cap is threadedly connected with the upper sealing body, so that the lower end of the second sieve plate extends into the first opening.

[0008] The present application has the beneficial effect that the present application allows the first opening communicating with the inner cavity of the sealing tube to be exposed by disassembling the cap, so that the filler in the inner cavity of the sealing tube is replaced through the first opening. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The structure of the column core in the specific embodiment of the present application is shown;

[0010] Figure 2 The cross-sectional view of the column core in the specific embodiment of the present application is shown.

[0011] Label explanation: 1, upper sealing body; 11, sink; 12, first extension plate; 13, groove; 14, horizontal plate; 15, first opening; 2, lower sealing body; 21, second extension plate; 22, second opening; 23, first sieve plate; 3, cap; 31, second base plate; 32, upper extension plate; 33, connecting plate; 34, second sieve plate; 35, lower extension plate; 4, sealing tube. DETAILED DESCRIPTION

[0012] To explain the technical content, the achieved purposes and effects of the present application in detail, the following will be explained in combination with the embodiments and the drawings.

[0013] Reference Figure 1 and Figure 2 As shown in the drawings, a protective column core includes an upper sealing body 1, a lower sealing body 2, a sealing tube 4 and a cap 3; the upper sealing body 1 and the lower sealing body 2 are used to close the two end openings of the sealing tube 4; the upper sealing body 1 is provided with a first opening 15, the lower sealing body 2 is provided with a second opening 22, and a first sieve plate 23 is embedded in the second opening 22; the cap 3 is provided with a third opening, and a second sieve plate 34 is embedded in the third opening; the cap 3 is threadedly connected with the upper sealing body 1, so that the lower end of the second sieve plate 34 extends into the first opening 15.

[0014] The sealing tube 4 is a hollow cylinder with both ends open, and the inner cavity for containing the filler is formed by closing the openings of both ends with the upper sealing body 1 and the lower sealing body 2. Meanwhile, the inner cavity can be connected with the outside environment through the first opening 15 provided on the upper sealing body 1 and the second opening 22 provided on the lower sealing body 2. The first opening 15 is closed by the cap 3, and specifically by the second sieve plate 34 provided on the third opening of the cap 3; the second opening 22 is closed by the second sieve plate 34. Therefore, in actual use, the high-pressure liquid phase (mixed liquid containing the measured substance and impurities and mobile phase) enters the inner cavity of the sealing tube 4 through the second sieve plate 34 and contacts the filler filled therein, and the impurities are enriched in the filler in the contacting process, while the measured substance mixed with the mobile phase flows out of the column core through the first sieve plate 23. The first sieve plate 23 and the second sieve plate 34 are both commercially available sieve plates, such as a porous filter plate sintered by stainless steel particles. The first opening 15 and the second opening 22 are sealed by the two respectively to avoid the filler overflowing in high pressure, and also to limit the large-particle impurities on the liquid inlet side of the second sieve plate 34 and the first sieve plate 23. The cap 3 is connected with the upper sealing body 1 by threads, so that the first opening 15 can be exposed by unscrewing the cap 3, thereby facilitating the replacement of the filler contained in the sealing tube 4, thereby reducing the cost. Preferably, the axes of the first opening 15, the second opening 22 and the third opening all coincide with the axis of the sealing tube 4.

[0015] It should be noted that in this paper, the outer side is the side away from the axis, and the inner side is the side close to the axis.

[0016] Of course, the threaded connection is difficult to support under high pressure, because the working height of the threads is limited due to the size, so in this embodiment, an additional sealing structure is needed to seal the connection area. Specifically, the upper sealing body 1 includes a first base plate, the top surface of which has a sink 11, the first opening 15 is arranged at the center of the sink 11, and the cap 3 is arranged in the sink 11; the bottom surface of the first base plate has an annular groove 13 for inserting the upper end of the sealing tube 4, and the edge of the bottom surface of the first base plate is provided with an annular first extension plate 12 extending axially downward along the first base plate, the inner side surface of the first extension plate 12 is in contact with and interference fit with the outer side surface of the sealing tube 4. Among them, the sink 11 is configured in the upper sealing body 1 to accommodate the cap 3, that is, the outer side surface of the cap 3 is connected to the side wall of the sink 11 by threads, at this time, the horizontal plate 14 used to configure the bottom surface of the sink 11 can effectively shield the gap between the cap 3 and the upper sealing body 1, and under high pressure, the high-pressure liquid below the horizontal plate 14 extrudes the horizontal plate 14 upward to make the bottom surface of the cap 3 on the top surface of the horizontal plate 14 contact sufficiently, thereby further reducing the gap between the two. The bottom surface of the first base plate also has a groove 13 for inserting one end of the sealing tube 4, which is preferably interference fit with the sealing tube 4, and the first extension plate 12 on the outer side of the sealing tube 4 and formed on the first base plate is also preferably interference fit, so it can effectively cover the outer surface of the sealing tube 4, thereby providing lateral support for the sealing tube 4 while extending the sealing length between the first base plate and the sealing tube 4. In the preparation method, after the sealing tube 4 is fixed, the upper sealing body 1 is pressed on the sealing tube 4 by high pressure, so that the two are almost in a difficult-to-disassemble state.

[0017] In one embodiment, the cap 3 has a second base plate 31, and the third opening is arranged at the center of the second base plate 31, and the outer side surface of the second base plate 31 is connected to the upper sealing body 1 by threads.

[0018] The third opening is provided with an upper extension plate 32 and a lower extension plate 35 extending axially upward and downward respectively along the second substrate 31, and the second screen plate 34 extends from the upper end surface of the upper extension plate 32 to the lower end surface of the lower extension plate 35. Preferably, the lower extension plate 35 wraps the outer side of the second screen plate 34 and extends into the first opening 15, and the outer side surface of the lower extension plate 35 is in contact with the side surface of the first opening 15. The gap fit or interference fit can be adopted between the lower extension plate 35 and the first opening 15, that is, the gap fit is used to improve the convenience of disassembly, and the interference fit is used to improve the sealing of the connection, but the area of contact between the two is small, so even if the interference fit is used, it still does not hinder the disassembly and assembly between the cap body 3 and the upper sealing body 1.

[0019] In an embodiment, the top surface of the second substrate 31 is provided with a connecting plate 33 extending from the upper end surface of the upper extension plate 32 to the top surface of the second substrate 31. That is, the connecting plate 33 connected to the upper extension plate 32 is arranged on the top surface of the second substrate 31, which provides lateral support for the upper extension plate 32 through the connecting plate 33, and also facilitates the user to rotate the cap body 3 for disassembly by using the connecting plate 33 as a similar knob structure. The disassembly can be a purely manual method or an additional tool method. The end surface of the additional tool has a matching structure matching the top surface of the cap body 3, and the matching structure is inserted on the cap body 3, and the matching tool is rotated to drive the cap body 3 to rotate.

[0020] Preferably, the vertical cross section of the connecting plate 33 is triangular.

[0021] Preferably, the connecting plate 33 is provided in multiple and is distributed at intervals along the circumference of the upper extension plate 32. The number of connecting plates 33 should not be too much, otherwise it is difficult for the user to directly use the interval between the connecting plates 33 to rotate the cap body 3. More preferably, the number of connecting plates 33 is three, which are distributed at equal intervals along the circumferential circumference of the upper extension plate 32.

[0022] In one embodiment, the lower sealing body 2 comprises a third base plate, the second opening 22 is arranged at the center of the third base plate, the outer edge of the third base plate is provided with a second extension plate 21 extending axially upward along the axis, the inner side of the second extension plate 21 is in contact with the outer side of the sealing tube 4. Wherein, the second extension plate 21 has the same function as the first extension plate 12, that is, wrapping the outer side of the sealing tube 4 to provide lateral support while sealing the lower end opening of the sealing tube 4. Therefore, preferably, the second extension plate 21 is in interference fit with the sealing tube 4. That is, in the preparation process, after fixing the upper sealing body 1, the sealing tube 4 is pressed into it, and then the upper sealing body 1 is pressed on the upper part of the sealing tube 4, so as to completely seal the axial two ends of the sealing tube 4, at this time, the filler is filled into the inner cavity of the sealing tube 4 through the first opening 15, and finally the cap 3 is screwed in to seal the first opening 15, that is, the installation of the column core is completed.

[0023] Preferably, the upper sealing body 1, the lower sealing body 2 and the cap 3 are integrally injection molded by PEEK (polyether ether ketone), and the sealing tube 4 is a stainless steel tube. Overall, the outer diameter of the column core is 4.6mm, the height is 10mm, and 0.1g of filler can be accommodated. The filling method of the filler can be wet filling or dry filling.

[0024] Embodiment 1

[0025] Referring to Figure 1 and Figure 2 , a protective column core comprises an upper sealing body 1, a lower sealing body 2, a sealing tube 4 and a cap 3;

[0026] The upper sealing body 1 and the lower sealing body 2 are used to seal the two end openings of the sealing tube 4;

[0027] The upper sealing body 1 is provided with a first opening 15, the lower sealing body 2 is provided with a second opening 22, and the second opening 22 is embedded with a first sieve plate 23;

[0028] The cap 3 is provided with a third opening, the third opening is embedded with a second sieve plate 34, and the cap 3 is threadedly connected with the upper sealing body 1, so that the lower end of the second sieve plate 34 extends into the first opening 15;

[0029] The axes of the first opening 15, the second opening 22 and the third opening all coincide with the axis of the sealing tube 4.

[0030] The upper cover 1 comprises a first base plate, the top surface of which has a sink 11, the first opening 15 is arranged at the center of the sink 11, and the cap 3 is arranged in the sink 11; the bottom surface of the first base plate has an annular groove 13 for inserting the upper end of the sealing tube 4, and the edge of the bottom surface of the first base plate is provided with an annular first extension plate 12 extending axially downward along the first base plate, the inner side surface of the first extension plate 12 is in contact with and has an interference fit with the outer side surface of the sealing tube 4;

[0031] The cap 3 has a second base plate 31, the third opening is arranged at the center of the second base plate 31, and the outer side surface of the second base plate 31 is connected to the upper cover 1 by screw threads;

[0032] The edge of the third opening is provided with an upper extension plate 32 and a lower extension plate 35 extending axially upward and downward respectively along the second base plate 31, and the second sieve plate 34 extends from the upper end surface of the upper extension plate 32 to the lower end surface of the lower extension plate 35;

[0033] The top surface of the second base plate 31 is provided with a connecting plate 33 extending from the upper end surface of the upper extension plate 32 to the top surface of the second base plate 31;

[0034] The vertical cross section of the connecting plate 33 is triangular;

[0035] The connecting plate 33 is arranged in three and is spaced apart along the circumference of the upper extension plate 32;

[0036] The outer side surface of the lower extension plate 35 is in contact with the side surface of the first opening 15;

[0037] The lower cover 2 comprises a third base plate, the second opening 22 is arranged at the center thereof, and the outer edge of the third base plate is provided with a second extension plate 21 extending axially upward therefrom, and the inner side surface of the second extension plate 21 is in contact with the outer side surface of the sealing tube 4.

[0038] Specifically, after the lower sealing body 2 is fixed, the sealing tube 4 is pressed into the lower sealing body 2, so that the outer side of the sealing tube 4 is in full contact with the inner side of the second extending plate 21, and then the upper sealing body 1 is pressed on the sealing tube 4, so that the upper end of the sealing tube 4 is inserted into the groove 13, and the outer side of the sealing tube 4 is in full contact with the inner side of the first extending plate 12. At this time, the filler is injected into the inner cavity of the sealing tube 4 through the first opening 15, and then the cap 3 is screwed into the sink 11 to close the first opening 15. In use, the high-pressure liquid phase is sent into the column core through the second sieve plate 34 and fully contacts with the filler in the column core, and finally flows out of the column core through the first sieve plate 23 and further flows into the chromatographic column. In the process of forming high pressure in the column core, the expansion of the filler exerts upward pressure on the horizontal plate 14 to seal the gap between the horizontal plate 14 and the cap 3 and to shield the gap between the threads between the cap 3 and the upper sealing body 1, thereby improving the overall sealing performance of the column core.

[0039] In summary, the present application allows the first opening communicating with the inner cavity of the sealing tube to be exposed by disassembling the cap on the upper sealing body, thereby facilitating the replacement of the filler in the inner cavity of the sealing tube through the first opening.

[0040] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent transformation or direct or indirect application in the related technical field based on the content of the specification and drawings of the present application is also included in the patent protection scope of the present application.

Claims

1. A guard column column core, characterized by, The upper sealing body, the lower sealing body, the sealing tube and the cap body are provided. The upper sealing body and the lower sealing body are used to seal the two ends of the sealing tube. The upper sealing body is provided with a first opening, and the lower sealing body is provided with a second opening. The cap body is provided with a third opening, and the second sieve plate is embedded in the third opening. The cap body is threadedly connected with the upper sealing body, so that the lower end of the second sieve plate extends into the first opening.

2. The guard column cartridge of claim 1, wherein, The upper sealing body comprises a first base plate, and the top surface of the first base plate is provided with a sink hole.

3. The guard column cartridge of claim 1 wherein, The first opening is arranged at the center of the sink hole, and the cap body is arranged in the sink hole.

4. The guard column cartridge of claim 3, wherein, The bottom surface of the first base plate is provided with an annular groove for inserting the upper end of the sealing tube.

5. The guard column cartridge of claim 4 wherein, The first base plate is provided with an annular first extension plate extending axially downward along the first base plate at the edge of the bottom surface.

6. The guard column cartridge of claim 5 wherein, The inner side surface of the first extension plate is in contact with and interference-fitted with the outer side surface of the sealing tube.

7. The guard column cartridge of claim 5 wherein, The axes of the first opening, the second opening and the third opening are coincident with the axis of the sealing tube.

8. The guard column cartridge of claim 4 wherein, The cap body is provided with a second base plate.

9. The guard column cartridge of claim 1 wherein, The third opening is arranged at the center of the second base plate. The outer side surface of the second base plate is connected with the upper sealing body through threads. The third opening is provided with an upper extension plate and a lower extension plate extending axially upward and downward respectively along the second base plate at the edge of the third opening. The second sieve plate extends from the upper end surface of the upper extension plate to the lower end surface of the lower extension plate. The top surface of the second base plate is provided with a connecting plate extending from the upper end surface of the upper extension plate to the top surface of the second base plate. The vertical cross section of the connecting plate is triangular. The connecting plate is provided in multiple and is distributed along the circumference of the upper extension plate. The outer side surface of the lower extension plate is in contact with the side surface of the first opening. The lower sealing body comprises a third base plate. The second opening is arranged at the center of the third base plate. The outer edge of the third base plate is provided with a second extension plate extending axially upward. The inner side surface of the second extension plate is in contact with the outer side surface of the sealing tube.

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