Needle for solid-phase extraction

Abstract

The solid-phase extraction needle comprises a stainless steel tube, a push rod, a fiber head and a fiber head falling-off structure, a limiting convex ring is arranged on the inner tube wall of the stainless steel tube, the push rod is inserted from the top of the stainless steel tube, the fiber head is detachably installed at the bottom of the push rod through a base, and the diameter of the base is larger than the outer diameter of the push rod; the fiber head dropping structure comprises a spring movably sleeved on the lower part of the push rod, a top ring fixed at the top of the spring and a bottom ring fixed at the bottom of the spring, the top ring and the bottom ring are respectively and movably sleeved on the push rod, and the aperture of the bottom ring is smaller than the diameter of the base. The device is simple in structure and convenient to operate, the fiber head and the push rod are separated through the elastic force, the fiber head automatically falls off, cross infection is prevented, and the integrity of the falling fiber head can be guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of solid phase extraction, in particular to a needle for solid phase extraction. Background Art

[0002] Solid phase extraction, referred to as SPE, is a sample pretreatment device developed from chromatography columns for extraction, separation, and concentration. It is developed by combining liquid-solid extraction columns and liquid chromatography technology. It is mainly used for sample separation, purification, and concentration. Compared with traditional liquid-liquid extraction methods, it can improve the recovery rate of analytes, more effectively separate analytes from interfering components, reduce sample pretreatment processes, and is simple to operate, time-saving, and labor-saving. It is widely used in the fields of medicine, food, environment, commodity inspection, and chemical industry.

[0003] The structure of the extraction needle used in solid phase extraction mostly includes a stainless steel tube, a push rod and a fiber head, wherein the push rod is inserted into the stainless steel tube, and the fiber head is detachably mounted on the push rod and coated with an adsorption coating on the surface. At present, there is no automatic shedding structure between the fiber head and the push rod, and the operator needs to manually disassemble the fiber head to replace it. Since the fiber head is made of quartz, this replacement method is likely to cause the fiber head to break. At the same time, this disassembly method is likely to cause the target object to spread and cause cross contamination. Utility Model Content

[0004] In view of this, the utility model aims to provide a needle for solid phase extraction, so as to realize rapid replacement of the fiber head on the extraction needle.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A needle for solid phase extraction, comprising a stainless steel tube, a push rod, a fiber head and a fiber head shedding structure, wherein the inner tube wall of the stainless steel tube is integrally formed with a limiting convex ring, and the limiting convex ring divides the stainless steel tube from top to bottom into a guide cavity and a receiving cavity, the push rod is inserted from the top of the stainless steel tube, and its bottom end passes through the limiting convex ring and enters the receiving cavity, the fiber head is located in the receiving cavity, and the fiber head is detachably mounted on the bottom of the push rod through a base, and the diameter of the base is larger than the outer diameter of the push rod;

[0007] The fiber head shedding structure includes a spring movably mounted on the lower part of the push rod, a top ring fixed on the top of the spring, and a bottom ring fixed on the bottom of the spring. The top ring and the bottom ring are movably mounted on the push rod respectively, and the aperture of the bottom ring is smaller than the diameter of the base.

[0008] Furthermore, the base and the push rod are connected by interference fitting.

[0009] Furthermore, the length of the accommodating cavity is 2-2.5 times the length of the fiber head.

[0010] Furthermore, the spring is a stainless steel spring, and the top ring and the bottom ring are both stainless steel rings.

[0011] Furthermore, a first handle portion is provided on the top of the stainless steel tube, and a second handle portion is provided on the top of the push rod.

[0012] Furthermore, the first handle portion is a resin or plastic handle.

[0013] Compared with the prior art, the solid phase extraction needle described in the utility model has the following advantages:

[0014] The utility model has a simple and compact structure and is easy to operate. The fiber head falling-off structure is mounted on the push rod. When the fiber head falling-off structure is clamped by the fiber head and the limiting convex ring, the spring is compressed, and the elastic force of the spring acts on the base of the fiber head. The elastic force is utilized to separate the fiber head and the push rod, so that the fiber head falls off automatically, thereby preventing the occurrence of cross infection and ensuring the integrity of the fallen fiber head. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0016] Figure 1 This is a schematic diagram of a needle structure for solid phase extraction according to an embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the stainless steel pipe structure in the embodiment of the utility model;

[0018] Figure 3 This is a schematic diagram of the fiber head falling off structure in this embodiment;

[0019] Figure 4 This is a diagram showing the relationship between the fiber head shedding structure, the limiting convex ring and the base position in this embodiment.

[0020] Description of reference numerals:

[0021] 1-stainless steel tube; 11-first handle; 12-limiting convex ring; 13-accommodating cavity; 14-guiding cavity; 2-push rod; 21-second handle; 3-spring; 4-fiber head; 5-top ring; 6-bottom ring; 7-base; 71-plug-in part. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0023] like Figure 1As shown, a needle for solid phase extraction includes a stainless steel tube 1, a push rod 2, a fiber head 4 and a fiber head shedding structure. The push rod 2 can be a stainless steel push rod or a PE push rod. The push rod 2 is inserted from the top of the stainless steel tube 1. A sealing ring structure is provided between the top of the stainless steel tube 1 and the push rod 2. The fiber head 4 is located in the stainless steel tube 1 and in the lower position of its internal space. The fiber head 4 is detachably installed at the bottom of the push rod 2. A fiber head shedding structure is provided between the push rod 2 and the fiber head 4.

[0024] The specific structure of stainless steel pipe is as follows Figure 2 As shown, a limiting convex ring 12 is integrally formed on the inner wall of the stainless steel tube 1, and the limiting convex ring 12 divides the stainless steel tube 1 into a guide cavity 14 and a receiving cavity 13. The guide cavity 14 is located above the receiving cavity 13, and the length of the receiving cavity 13 is 2-2.5 times the length of the fiber head 4.

[0025] Fiber head shedding structure Figure 3 As shown, it includes a spring 3, a top ring 5 fixed on the top of the spring 3, and a bottom ring 6 fixed on the bottom of the spring 3. The inner diameters of the top ring 5 and the bottom ring 6 are set corresponding to the diameter of the push rod 2 to ensure that the top ring 5 and the bottom ring 6 are respectively matched with the push rod 2.

[0026] The specific assembly structure of the fiber head shedding structure, the push rod 2 and the fiber head 4 is as follows: Figure 4 As shown, the bottom end of the push rod 2 passes through the guide cavity 14 and the limiting convex ring 12 and enters the accommodating cavity 13. The fiber head 4 is located in the accommodating cavity 13. The fiber head 4 is matched with a cylindrical base 7. The diameter of the base 7 is larger than the outer diameter of the push rod 2. A plug-in portion 71 protrudes from the top of the base 7. The plug-in portion 71 is inserted into the plug-in hole matched with the push rod 2 through interference fit, so that the fiber head 4 and the push rod 2 are fixed and detachably connected. The spring 3, the top ring 5 and the bottom ring 6 are all movably mounted on the push rod 2. The bottom ring 6 is supported by the base 7. The top ring 5 is located above the bottom ring 6 and corresponds to the limiting convex ring 12.

[0027] In the utility model, the spring 3 is a stainless steel spring, and the top ring 5 and the bottom ring 6 are both stainless steel rings.

[0028] In the utility model, a first handle portion 11 is provided on the top of the stainless steel tube 1, and a second handle portion 21 is provided on the top of the push rod 2. This structure is convenient for manual grasping and operation.

[0029] In the present invention, the first handle portion 11 is a resin or plastic handle.

[0030] The operation process of the utility model is as follows: after the extraction of the fiber head 4 is completed, the push rod 2 is pulled up, and the fiber head 4 and the fiber head falling-off structure are moved upward until the fiber head falling-off structure is clamped by the base 7 and the limiting convex ring 12. At this time, the top ring 5 abuts against the limiting convex ring 12, and the push rod 2 continues to be pulled up, and the spring 3 of the fiber head falling-off structure is compressed. The elastic force of the spring 3 acts on the base 7 through the bottom ring 6. As the pull rod continues to move upward, the spring 3 is continuously compressed and the elastic force increases until the base 7 together with the fiber head 4 is removed, thereby realizing the automatic falling-off of the fiber head.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A needle for solid phase extraction, Features: The invention comprises a stainless steel tube (1), a push rod (2), a fiber head (4) and a fiber head shedding structure. The inner tube wall of the stainless steel tube (1) is integrally formed with a limiting convex ring (12). The limiting convex ring (12) divides the stainless steel tube (1) into a guide cavity (14) and a receiving cavity (13) from top to bottom. The push rod (2) is inserted from the top of the stainless steel tube (1), and its bottom end passes through the limiting convex ring (12) and enters the receiving cavity (13). The fiber head (4) is located in the receiving cavity (13). The fiber head (4) is detachably mounted on the bottom of the push rod (2) through a base (7). The diameter of the base (7) is larger than the outer diameter of the push rod (2). The fiber head shedding structure comprises a spring (3) movably mounted on the lower part of the push rod (2), a top ring (5) fixed on the top of the spring (3), and a bottom ring (6) fixed on the bottom of the spring (3); the top ring (5) and the bottom ring (6) are movably mounted on the push rod (2), respectively, and the aperture of the bottom ring (6) is smaller than the diameter of the base (7).

2. A solid phase extraction needle according to claim 1, Features: The base (7) and the push rod (2) are connected by interference fitting.

3. A solid phase extraction needle according to claim 1, Features: The length of the accommodating cavity (13) is 2-2.5 times the length of the fiber head (4).

4. A solid phase extraction needle according to claim 1, Features: The spring (3) is a stainless steel spring, and the top ring (5) and the bottom ring (6) are both stainless steel rings.

5. A solid phase extraction needle according to claim 1, Features: A first handle portion (11) is provided on the top of the stainless steel tube (1), and a second handle portion (21) is provided on the top of the push rod (2).

6. A solid phase extraction needle according to claim 5, Features: The first handle portion (11) is a resin or plastic handle.

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