A pre-compressed solid-phase extraction column tube with adjustable pressing force and its usage method

Abstract

The present invention discloses a pre-compressed solid-phase extraction column tube with adjustable pressing force and its usage method. The pre-compressed solid-phase extraction column tube with adjustable pressing force includes a screw cap, an outer column tube, an inner column tube sleeved inside the outer column tube, and a spring sleeved on the inner column tube. The screw cap and the outer column tube are connected by threads. A round hole is provided at the center of the screw cap. The upper part of the inner column tube passes through the screw cap through the round hole and is arranged at the top end of the screw cap. The bottom of the inner column tube is provided with a lower edge of the inner column tube. The top end of the spring is connected to the screw cap, and the bottom end of the spring is connected to the lower edge of the inner column tube. An integral column bed is arranged inside the outer column tube. The top of the integral column bed is connected to the bottom of the lower edge of the inner column tube. A Luer connector is provided at the bottom of the outer column tube. The pre-compressed solid-phase extraction column tube with adjustable pressing force proposed by the present invention compensates for the shrinkage of the column bed during the removal of pore-forming agent and the drying of the column bed of the integral column, preventing phenomena such as cracks in the integral column bed and detachment from the column tube to adapt to the elastic integral column.

Description

Technical Field:

[0001] The present invention relates to the technical field of solid-phase extraction, and particularly relates to a pre-compressed solid-phase extraction column tube with adjustable pressing force and its usage method. Background Art:

[0002] The monolithic column is a new type of porous separation and enrichment material, which can be widely used as the packing of solid-phase extraction columns and chromatographic separation columns. The monolithic column has a connected three-dimensional network microstructure. When in-situ polymerization is completed, the liquid substances in the raw material mixture that do not participate in the polymerization reaction (usually called porogens) are filled in the internal network pores of the monolithic column. In the subsequent preparation process, solvents such as acetonitrile, methanol, and isopropanol need to be used to wash out the porogens to make the monolithic column available for use. The materials constituting the network structure of the monolithic column may have different hardnesses and elasticities. When the monolithic column material has a high rigidity, after the solvent in the voids volatilizes, the monolithic column material can still maintain the three-dimensional network structure and size, without affecting the performance and usage effect of the monolithic column; while some materials have good stretchability, and the monolithic column made can maintain a complete shape and size only when it is filled with solvent inside. When the solvent is lost or volatilized, the internal pores will deform due to lack of support, and the entire column bed structure will shrink. When it exceeds a certain degree, the spatial structure will collapse, resulting in disordered local cracking or detachment from the column tube, and the entire column will be scrapped and can no longer be used as the stationary phase of liquid chromatography or solid-phase extraction. This phenomenon limits the application of some elastic materials as monolithic column materials. To address this problem, the domestic and foreign research and application fields mainly adopt methods to prevent the solvent in the monolithic column bed from volatilizing as much as possible, such as sealing both ends of the monolithic column or immersing the entire column in a solvent to prevent drying. Although these measures have certain effects, there are still inconveniences, and it is urgent to solve this problem through other means. Summary of the Invention:

[0003] In order to solve the problems existing in the prior art, the present invention proposes a pre-compressed solid-phase extraction column tube with adjustable pressing force and its usage method. In the present invention, a pressing force is continuously applied in one direction of the monolithic column bed by using a spring. As the porogen is removed, the spring can gradually elongate and increase the compression amount, so that the shrinkage phenomenon of the monolithic column bed can be controlled to proceed orderly in one direction, preventing the occurrence of internal gaps, cavities, and detachment from the tube wall. The magnitude of the spring force applied to the monolithic column bed can be adjusted by selecting appropriate spring parameters and adjusting the spring pre-compression amount.

[0004] The object of the present invention is to provide a pre-compressed solid-phase extraction column tube with adjustable pressing force, which comprises a screw cap, an outer column tube, an inner column tube sleeved inside the outer column tube, and a spring sleeved on the inner column tube. The screw cap and the outer column tube are connected by threads. A circular hole is provided at the center of the screw cap. The upper part of the inner column tube passes through the screw cap through the circular hole and is arranged at the top of the screw cap. The bottom of the inner column tube is provided with a lower edge of the inner column tube. The top end of the spring is connected to the screw cap, and the bottom end of the spring is connected to the lower edge of the inner column tube. An integral column bed is arranged inside the outer column tube, and the top of the integral column bed is connected to the bottom of the lower edge of the inner column tube. A Luer connector is provided at the bottom of the outer column tube. Both the inner column tube and the outer column tube proposed by the present invention are cylindrical column tubes.

[0005] The mechanical space compensation method used in the present invention can, to a certain extent, overcome the problem of shrinkage of the elastic integral column bed, and can be applied to various elastic solid-phase extraction fillers to expand the selection and application range of integral column materials.

[0006] The existing copolymer integral columns have the problem of easy cracking, which affects the characterization and application of the integral columns. To solve this problem, in addition to adjusting the polymerization parameters to increase the strength of the integral column structure and prevent the column bed from drying and shrinking, the pre-compressed solid-phase extraction column tube with adjustable pressing force proposed by the present invention compensates for the shrinkage of the column bed during the removal of porogens and the drying of the column bed of the integral column, preventing phenomena such as cracks and detachment from the column tube in the integral column bed to adapt to the elastic integral column. The mechanical space compensation method can, to a certain extent, overcome the problem of shrinkage of the elastic integral column bed and expand the selection and application range of integral column materials.

[0007] The technical principle of the pre-compressed solid-phase extraction column tube with adjustable pressing force proposed by the present invention is as follows: After the integral column prepared from an elastic material is polymerized, during the process of flushing and removing the porogens therein, due to the loss of the support of the internal filling liquid in the spatial network structure, shrinkage and cracking may occur. If a pressing force is continuously applied in one direction of the column bed by a spring during the removal of the porogens, as the porogens are removed, the spring can gradually elongate and increase the compression amount, so that the shrinkage phenomenon of the integral column bed can be controlled to proceed orderly in one direction, preventing the occurrence of internal gaps, cavities, and detachment from the tube wall. The magnitude of the spring force applied to the integral column bed can be adjusted by selecting appropriate spring parameters and adjusting the spring pre-compression amount.

[0008] Preferably, the inner column tube is a hollow cylinder with openings at both the top and the bottom, and the outer diameter of the inner column tube is smaller than the inner diameter of the outer column tube.

[0009] Preferably, the outer wall of the outer column tube is provided with scales, and the screw cap is provided with a scale pointer for jointly identifying the screwing-in amount of the screw cap with the scales. The screw cap and the outer column tube are connected by threads, and there is a large margin of the threads, so that the height of the screw cap can be adjusted by the rotation angle within a large range. The screw cap is provided with a scale pointer for jointly identifying the screwing-in amount of the screw cap with the scales on the outer wall of the outer column tube.

[0010] Preferably, the screw cap is internally provided with an internal screw thread of the screw cap, and the outer wall of the outer column tube is provided with an external screw thread of the tube wall. The screw cap and the outer column tube are connected through the internal screw thread of the screw cap and the external screw thread of the tube wall.

[0011] Preferably, the Luer connector is connected in cooperation with the Luer plug. A cylinder extending into the interior of the Luer connector to fill its internal channel is arranged at the center inside the Luer plug. In the present invention, the top end of the inner column tube is sealed with a sealing cap, and the bottom end of the solid-phase extraction column is sealed with the Luer plug to prevent the column bed of the whole column from being completely dried.

[0012] Preferably, a sieve plate is arranged between the inner column tube and the column bed of the whole column. A sieve plate made of a sintered material is embedded at the lower end of the inner column tube. The lower edge of the inner column tube and the sieve plate clamped at the lower edge of the inner column tube together press the top end of the column bed of the whole column. The lower part of the column bed prepared by in-situ polymerization can directly use the bottom of the outer column tube for support without using a sieve plate.

[0013] The present invention also protects the application of the pre-compressed solid-phase extraction column tube with adjustable pressing force in solid-phase extraction. The specific usage method of the pre-compressed solid-phase extraction column tube with adjustable pressing force is as follows: When preparing the whole column, remove the screw cap, the inner main tube and the spring, block the lower end of the outer column tube with the Luer plug, and place the outer column tube vertically. Add the prepared liquid polymerization monomer mixture into the outer column tube, block the upper end of the outer column tube with a sealing cap, and place it at a certain temperature for in-situ polymerization reaction to prepare the column bed of the whole column. After the polymerization reaction is completed, insert the inner column tube with a sieve plate and a spring to press the column bed of the whole column, screw on the screw cap, and adjust the screw cap to a preset position so that the spring presses the inner column tube downward with a certain pressure; remove the Luer plug at the bottom of the outer column tube, connect the inner column tube to a vacuum-assisted device for flushing, add the flushing solvent from the upper opening of the inner column tube, and turn on the vacuum. During the process of flushing and removing the porogen, as the porogen is flushed and replaced, longitudinal shrinkage occurs in the column bed of the whole column, and the inner column tube and the sieve plate will be pushed inward under the spring pressure to compensate for the shrinkage amount of the column bed, thereby preventing the column bed from cracking. After flushing, the top end of the inner column tube can be sealed with a sealing cap, and the bottom end of the solid-phase extraction column can be sealed with the Luer plug to prevent the column bed of the whole column from being completely dried. For the prepared elastic material solid-phase extraction whole column, the following steps are carried out for solid-phase extraction operation: Before use, remove the sealing caps and plugs at both ends of the column tube, install the solid-phase extraction column tube on the vacuum-assisted device, flush and activate the column bed with an appropriate solvent of a certain volume, and then carry out sample loading, elution and elution according to the operation mode of a conventional solid-phase extraction column.

[0014] The present invention has the following advantages compared with the prior art: The pre-compressed solid-phase extraction column tube with adjustable pressing force proposed by the present invention compensates for the shrinkage of the column bed during the removal of the porogen and the drying of the column bed of the monolithic column, preventing phenomena such as cracks and detachment of the column bed of the monolithic column from the column tube to adapt to the elastic monolithic column. The mechanical space compensation method used in the present invention can overcome the problem of column bed shrinkage of the elastic monolithic column to a certain extent, expanding the selection and application range of monolithic column materials. Description of the drawings:

[0015] Figure 1 It is a schematic structural diagram of the pre-compressed solid-phase extraction column tube with adjustable pressing force of the present invention;

[0016] Figure 2 is Figure 1 A cross-sectional view taken along the longitudinal direction;

[0017] Figure 3 is Figure 1 A schematic exploded view of the structure of;

[0018] Description of the reference numerals: 1, screw cap; 2, spring; 3, inner column tube; 4, lower edge of the inner column tube; 5, sieve plate; 6, monolithic column bed; 7, outer column tube; 8, Luer connector; 9, Luer plug; 10, scale pointer; 11, scale; 12, internal thread of the screw cap; 13, external thread of the tube wall. Detailed implementation manners:

[0019] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with 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 making creative efforts belong to the scope of protection of the present invention. Unless otherwise specified, the equipment and reagents used in the present invention are conventional commercially available products in the technical field.

[0020] The pre-compressed solid-phase extraction column tube with adjustable pressing force proposed by the present invention consists of four parts, namely the upper screw cap 1, the inner column tube 3 and the outer column tube 7 which are nested inside and outside, and the spring 2 between the inner column tube 3 and the outer column tube 7. The screw cap 1 and the outer column tube 7 are connected by threads, and there is a large margin in the threads, so that the height of the screw cap 1 can be adjusted within a large range by rotating the angle. A scale pointer 10 is engraved on the screw cap 1 to jointly identify the screwing-in amount of the screw cap 1 with the scale on the outer wall of the outer column tube 7. There is a round hole in the center of the screw cap 1, and the top end of the inner column tube 3 extends out through the round hole on the screw cap 1. The inner column tube 3 is a hollow cylinder with openings at both the upper and lower ends, and its outer diameter is smaller than the inner diameter of the outer column tube. A lower edge 4 of the inner column tube with an outer diameter slightly smaller than the inner diameter of the outer column tube 7 is provided at the lower end of the inner column tube 3. When the inner column tube 3 is inserted into the outer column tube 7, a clearance fit is directly formed between the lower edge 4 of the inner column tube of the inner column tube 3 and the inner wall of the outer column tube 7, and the inner column tube 3 can move freely up and down relative to the outer column tube 7. The diameter of the helical part of the spring 2 is between the outer column tube 7 and the inner column tube 3, and it is sleeved on the inner column tube 3. The upper end of the spring 2 is pressed by the screw cap 1, and the lower end abuts against the lower edge 4 of the inner column tube. The compression tightness of the spring 2 can be adjusted by the screwing-in amount of the screw cap 1. A sieve plate 5 made of sintered material is embedded at the lower end of the inner column tube 3. Together with the lower edge 4 of the inner column tube, the sieve plate 5 presses the top end of the overall column bed 6. The lower part of the overall column bed prepared by in-situ polymerization does not use a sieve plate and is directly supported by the bottom of the outer column tube 7. The lower end of the outer column tube 7 can be sealed with a Luer plug 9 of the Luer fitting 8 specification. There is a cylinder in the center of the Luer plug 9 that can extend into the Luer fitting 8 to fill its internal channel.

[0021] In the pre-compressed solid-phase extraction column tube with adjustable pressing force, the screw cap 1 can adjust the downward compression distance of the spring 2 by the number of turns of its thread engagement with the outer column tube 7. The outer wall of the outer column tube 7 has a scale to identify the screwing-in amount of the screw cap 1, so as to set the magnitude of the spring elastic force. The cylindrical overall column bed 6 after polymerization is located at the bottom of the outer column tube 7, supported by the bottom end of the outer column tube 7 below, and the upper end is pressed by the inner column tube 3 and the sieve plate 5 on its bottom surface, and the pressure comes from the spring elastic force. A monomer mixture can be added to the outer column tube 7 for in-situ polymerization reaction to prepare the overall column bed. After the polymerization reaction is completed, the inner column tube 3 with the sieve plate 5 and the spring 2 is inserted to press the overall column bed 6, and the screw cap 1 is screwed on. The screw cap 1 is adjusted to a preset position so that the spring 2 presses the inner column tube 3 downward with a certain pressure. The Luer plug 9 at the bottom of the outer column tube 7 is removed, and the inner column tube 3 is connected to a vacuum-assisted device for flushing. The flushing solvent is added from the upper opening of the inner column tube 3, and the vacuum is turned on. During the process of flushing and removing the porogen, as the porogen is flushed and replaced, longitudinal shrinkage occurs on the overall column bed 6, and the inner column tube 3 and the sieve plate 5 will be pushed inward under the pressure of the spring 2 to compensate for the shrinkage amount of the overall column bed 6, thereby preventing the overall column bed 6 from cracking. After flushing, the top end of the inner column tube is sealed with a cap, and the bottom end of the solid-phase extraction column is sealed with a Luer plug to prevent the overall column bed from drying out completely.

[0022] Example 1

[0023] As Figures 1 - 3 shown, an adjustable compression force pre-compressed solid phase extraction column tube includes a screw cap 1, an outer column tube 7, an inner column tube 3 sleeved inside the outer column tube 7, and a spring 2 sleeved on the inner column tube 3. The screw cap 1 and the outer column tube 7 are connected by threads. A circular hole is provided at the center of the screw cap 1. The upper part of the inner column tube 3 passes through the screw cap 1 through the circular hole and is arranged at the top of the screw cap 1. The bottom of the inner column tube 3 is provided with a lower edge 4 of the inner column tube. The top end of the spring 2 is connected to the screw cap 1, and the bottom end of the spring 2 is connected to the lower edge 4 of the inner column tube. An integral column bed 6 is arranged inside the outer column tube 7. The top of the integral column bed 6 is connected to the bottom of the lower edge of the inner column tube 3. A Luer connector 8 is arranged at the bottom of the outer column tube 7. In this embodiment, it is preferred that both the inner column tube 3 and the outer column tube 7 are cylindrical column tubes. The spring 2 can select a spring with appropriate spring parameters according to actual needs to adjust the spring pre-compression amount. The integral column bed is made of a porous integral material with certain elasticity. The inner column tube 3 is a hollow cylinder with openings at both the upper and lower ends, and the outer diameter of the inner column tube 3 is smaller than the inner diameter of the outer column tube 7. A scale 11 is arranged on the outer wall of the outer column tube 7, and a scale pointer 10 for jointly marking the screwing-in amount of the screw cap 1 with the scale 11 is arranged on the screw cap 1. A screw cap inner thread 12 is arranged inside the screw cap 1, and a tube wall outer thread 13 is arranged on the outer wall of the outer column tube 7. The screw cap 1 and the outer column tube 7 are connected by the screw cap inner thread 12 and the tube wall outer thread 13. The screw cap 1 and the outer column tube 7 are connected by threads, and there is a large margin in the threads, and the height of the screw cap can be adjusted within a large range by rotating the angle. A scale pointer 10 is arranged on the screw cap 1 for jointly marking the screwing-in amount of the screw cap 1 with the scale on the outer wall of the outer column tube 7.

[0024] The Luer connector 8 is cooperatively connected with a Luer plug 9. A cylinder extending into the interior of the Luer connector 8 to fill its internal channel is arranged at the center inside the Luer plug 9. In the present invention, the top end of the inner column tube is sealed with a cap, and the bottom end of the solid phase extraction column is sealed with a Luer plug to prevent the integral column bed from drying out completely.

[0025] A sieve plate 5 is arranged between the inner column tube 3 and the integral column bed 6. A sieve plate 5 made of a sintered material is embedded at the lower end of the inner column tube 3. The lower edge 4 of the inner column tube and the sieve plate 5 clamped at the lower edge of the inner column tube 3 together press the top end of the integral column bed 6. For the column bed prepared by in-situ polymerization, a sieve plate may not be used at the lower part, and it can be directly supported by the bottom of the outer column tube 7.

[0026] The technical principle of the adjustable compression force pre-compression type solid-phase extraction column tube proposed by the present invention is as follows: after the integral column prepared from the elastic material is polymerized, during the process of flushing and removing the porogen therein, due to the loss of the support of the internal filling liquid in the spatial network structure, shrinkage and cracking may occur. If a pressing force is continuously applied by a spring in one direction of the column bed during the removal of the porogen, as the porogen is removed, the spring can gradually elongate and increase the compression amount, so that the shrinkage phenomenon of the integral column bed can be controlled to proceed orderly in one direction, preventing the occurrence of internal gaps, cavities and detachment from the tube wall. The magnitude of the spring force applied to the integral column bed can be adjusted by selecting appropriate spring parameters and adjusting the spring pre-compression amount.

[0027] The adjustable compression force pre-compression type solid-phase extraction column tube proposed by the present invention can overcome the problem of shrinkage of the elastic integral column bed to a certain extent by using the mechanical space compensation method. It can not only be used in combination with the integral column packing, but also be applied to other fillers with certain elasticity to expand the selection and application range of the integral column materials.

[0028] The description of the above embodiments is only used to help understand the technical solution and its core idea of the present invention. It should be noted that for those skilled in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A pre-compressed solid-phase extraction column tube with adjustable pressing force, characterized in that, It includes a screw cap, an outer column tube, an inner column tube sleeved inside the outer column tube, and a spring sleeved on the inner column tube. The screw cap and the outer column tube are connected by threads. A round hole is provided in the center of the screw cap. The upper part of the inner column tube passes through the screw cap through the round hole and is arranged at the top of the screw cap. The bottom of the inner column tube is provided with a lower edge of the inner column tube. The top end of the spring is connected to the screw cap, and the bottom end of the spring is connected to the lower edge of the inner column tube. An elastic monolithic column bed is arranged inside the outer column tube, and the top of the monolithic column bed is connected to the bottom of the lower edge of the inner column tube. A Luer connector is arranged at the bottom of the outer column tube; a scale is arranged on the outer wall of the outer column tube, and a scale pointer for jointly marking the screwing-in amount of the screw cap with the scale is arranged on the screw cap; a sieve plate is arranged between the inner column tube and the monolithic column bed.

2. The pre-compressed solid phase extraction column tube with adjustable pressing force according to claim 1, wherein, The inner column tube is a hollow cylinder with openings at both the top and the bottom, and the outer diameter of the inner column tube is smaller than the inner diameter of the outer column tube.

3. The pre-compressed solid-phase extraction column tube with adjustable pressing force according to claim 1, wherein Internal screw threads are provided inside the screw cap, and external screw threads are provided on the outer wall of the outer column tube. The screw cap and the outer column tube are connected through the internal screw threads of the screw cap and the external screw threads of the tube wall.

4. The pre-compressed solid-phase extraction column tube with adjustable pressing force according to claim 1, wherein, The Luer connector is connected in cooperation with a Luer plug, and a cylinder that extends into the inside of the Luer connector to fill its internal channel is arranged at the center inside the Luer plug.

5. Application of the pre-compressed solid-phase extraction column tube with adjustable pressing force described in claim 1 in solid-phase extraction.

Images