CN107389834B - Visual low pressure isotope separation chromatographic column - Google Patents

Abstract

The invention provides a visible low-pressure isotope separation chromatography column, comprising a column tube, a column head, a sieve plate and a sealing ring. The column head includes an upper part of the column head, and the inner wall of the upper part of the column head is provided with a first cavity and a second cavity , the second cavity communicates with the first cavity, a sieve plate is placed in the second cavity close to the first cavity, and a sealing ring is embedded in the periphery of the sieve plate, and the sealing ring is connected to the second cavity. The inner wall of the cavity is in close contact and compression, a sealing ring is sleeved on the column tube, the sealing ring is fitted with the column tube, the column tube is inserted into the second cavity on the upper part of the column head, and the outer side of the sealing ring follows the cylinder head. With the column tube inserted into the second cavity, the sealing ring is squeezed to be in close contact with the inner wall of the second cavity under the action of elastic force, the column tube is in contact with the sieve plate, and is tightly connected with the sealing ring fit, so that the column tube is fixedly connected to the upper part of the column head. The present invention has good acid-base resistance and transparency properties.

Description

A Visual Low Pressure Isotope Separation Chromatography Column

technical field

The invention relates to the technical field of isotope analysis instruments, in particular to a visible low-pressure isotope separation chromatographic column.

Background technique

At present, the liquid chromatography exchange column is mainly made of stainless steel and PEEK (polyetheretherketone, polyetheretherketone) material, which has a simple structure and is widely used in gas-liquid phase analysis laboratories. Experiments have shown that the chromatographic exchange column made of stainless steel has poor tolerance to strong acids, so it cannot be widely used in chromatographic separation with acid as the mobile phase, while the chromatographic exchange column made of PEEK material has a strong acid resistance. Certain tolerance, however, the tolerance to nitric acid and hydrofluoric acid commonly used in the isotope analysis process is not good, therefore, in the liquid chromatography analysis process, involving strong acid as the chromatographic separation of the eluent , there is no chromatographic exchange column with good adaptability.

Polyfluoroethylene propylene (FEP) is a copolymer of tetrafluoroethylene and hexafluoropropylene. Its chemical resistance is similar to that of polytetrafluoroethylene, and it has excellent chemical resistance. Except for the reaction between alkali metal and chlorine trifluoride, it will not be corroded when in contact with other chemicals. It is widely used in high-purification analysis, especially isotope analysis in the field of geochemistry. FEP material has the characteristics of acid and alkali resistance and low background , has been widely used by laboratories in the field of isotope analysis around the world, and is currently mainly used for the storage of high-purity reagents. For example, the well-known Nalgene company in the United States uses vessels made of FEP materials for ultra-trace analysis experiments. At present, there is no ion-exchange chromatographic column made of FEP that can be applied to the separation of low-pressure liquid chromatography.

In addition, traditional ion exchange columns made of stainless steel and PEEK have the following disadvantages: it is difficult to observe the elution changes of the stationary phase (ion exchange resin) and mobile phase during ion chromatography, especially for low pressure chromatography In this process, due to the use of a stationary phase with a large porosity (ion exchange resin, etc.), the occurrence of air bubbles during the chromatography process and the drying of the stationary phase due to poor pressure control will seriously affect the effect of isotope chromatography separation and purification. , while traditional ion exchange columns made of stainless steel and PEEK cannot observe this phenomenon. Moreover, because the inner wall of the PEEK tube is more difficult to process, its smoothness is far lower than that of the inner wall of the FEP tube. The tube wall effect during layer separation is also significantly larger than that of the FEP tube. The low-pressure chromatography column made of glass currently on the market will cause the dissolution of potassium and sodium ions in the glass for the strong acid substances involved in the isotope analysis process, which cannot meet the needs of isotope trace analysis. The joint and the sieve plate made of plastic are a whole, which is not easy to clean the joint and the sieve plate, nor can it be suitable for the international general chromatographic hand-tight joint.

Contents of the invention

In view of this, the present invention provides a visible low-pressure isotope separation chromatographic column with good acid-base tolerance and transparency.

The invention provides a visible low-pressure isotope separation chromatography column, which includes a column tube, a column head, a sieve plate and a sealing ring, the column head includes an upper part of the column head, and the inner wall of the upper part of the column head is provided with a first cavity and a second cavity , the second cavity communicates with the first cavity, a sieve plate is placed in the second cavity close to the first cavity, the periphery of the sieve plate is inlaid with a sealing ring, and the sealing ring is connected to the second cavity The inner wall of the cavity is tightly contacted and pressed, the column tube is covered with a sealing ring, the sealing ring is attached to the column tube, the column tube is inserted into the second cavity on the upper part of the column head, and the outer side of the sealing ring is The column tube is inserted into the second cavity, and the sealing ring is squeezed to be in close contact with the inner wall of the second cavity under the action of elastic force, and the column tube is in contact with the sieve plate and is tightly connected to the sealing ring so that the column tube is fixedly connected to the upper part of the column head, and the column tube is made of acid-resistant, alkali-resistant, flexible and transparent materials.

Further, the stigma also includes a lower part of the stigma, the inner wall of the lower part of the stigma is provided with a third cavity, the column tube is inserted into the third cavity, the lower part of the stigma can slide along the column tube, the first The third cavity is provided with a second internal thread, and the outside of the second cavity is provided with a first external thread, and the second internal thread is mated with the first external thread so as to connect the upper part of the stigma with the lower part of the stigma. When the second internal thread is mated with the first external thread, the sealing ring is squeezed to achieve tight contact and compression between the sealing ring and the inner wall of the second cavity.

Further, the chromatographic column also includes a joint matching the column head, the lower end of the joint is provided with a second external thread, the first cavity on the upper part of the column head is provided with a first internal thread, and the second external thread The thread is mated with the first internal thread so as to connect the joint with the upper part of the column head. The joint is provided with a through hole, and the lower end of the joint is connected with a butt joint. Both the joint and the butt joint are made of polytetrafluoroethylene.

Further, the sealing ring includes an upper bottom surface and a lower bottom surface, the diameter of the upper bottom surface is smaller than the diameter of the lower bottom surface, the diameter of the upper bottom surface is consistent with the inner diameter of the column tube, and the diameter of the lower bottom surface is the same as the outer diameter of the column tube. The diameter is the same, and the shape of the sealing ring is a cone shape.

Further, the inner diameter of the sealing ring is consistent with the inner diameter of the column tube, and the diameter of the second cavity is larger than the outer diameter of the column tube.

Further, the upper part of the column head and the lower part of the column head are provided with locking slots, and the upper part of the column head and the lower part of the column head can be rotated by turning the locking slots with a wrench, so as to ensure the tight connection between the upper part of the column head and the lower part of the column head.

Further, the column head, the sieve plate, the sealing ring and the sealing ring are all made of polytetrafluoroethylene.

Further, the column tube is made of polyperfluoroethylene propylene material.

Further, column heads are installed at both ends of the column tube, and the structures of the two column heads are the same.

Further, the inside of the column tube is filled with resin. After the sample is added by the sample injector, it flows into the butt joint along the through hole, and then flows out to the second cavity along the inner wall of the butt joint, and the sample passes through the second cavity. After the sieve plate in the cavity is sieved, it flows into the column tube for the separation process.

The beneficial effects brought by the technical scheme provided by the invention are:

1. The visible low-pressure isotope separation chromatographic column provided by the present invention has good tolerance to acid and alkali, and has wider application prospects in the field of low-pressure chromatographic separation compared with traditional ion exchange columns;

2. The column tube of the present invention has good transparency characteristics, and can observe the change of the stationary phase in the process of ion chromatography at any time, and improve the reliability of judging the effect of low-pressure isotope chromatography separation and purification;

3. The present invention does not need to process threads on the column tube, which reduces the processing technology, and the length of the column tube can be adjusted according to needs, which is convenient to use;

4. The column head and the sieve plate of the visual low-pressure isotope separation chromatography column provided by the present invention are separated structures, which are easy to install and clean, and are suitable for international general chromatography hand-tight joints.

Description of drawings

Fig. 1 is a schematic structural view of a visible low-pressure isotope separation chromatography column of the present invention.

Fig. 2 is a front view of a visible low pressure isotope separation chromatography column of the present invention.

Fig. 3 is a schematic structural view of a column head of a visible low-pressure isotope separation chromatography column according to the present invention.

Fig. 4 is a schematic structural view of a column tube of a visible low-pressure isotope separation chromatography column according to the present invention.

Fig. 5 is a structural schematic diagram of a sealing ring of a visible low-pressure isotope separation chromatography column according to the present invention.

Fig. 6 is a structural schematic diagram of a joint of a visible low-pressure isotope separation chromatography column according to the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Please refer to Fig. 1, Fig. 2 and Fig. 3, the embodiment of the present invention provides a kind of visual low-pressure isotope separation chromatography column, including column tube 1, column head 2, sieve plate 3, sealing ring 4 and the joint matched with the column head 5. The stigma 2 includes an upper stigma 21 and a lower stigma 22 that are mated and connected. The joint 5 is connected to the upper stigma 21. The lower stigma 22 can slide along the column tube 1. The inner wall of the upper stigma 21 is provided with a first cavity 211 and a second cavity. Cavity 213, the second cavity 213 communicates with the first cavity 211, the first cavity 211 is provided with the first internal thread 212, the joint 5 is inserted in the first cavity 211, the outside of the second cavity 213 is provided with The first external thread 214, the sieve plate 3 is placed in the second cavity 213 close to the first cavity 211, the periphery of the sieve plate 3 is embedded with a sealing ring 4, and the sealing ring 4 is in close contact with the inner wall of the second cavity 213 and compressed , the inner wall of the lower stigma 22 is provided with a third cavity 221, the third cavity 221 is provided with a second internal thread 222, and the second internal thread 222 is connected with the first external thread 214 so as to connect the upper stigma 21 and the lower stigma 22 Connection, in one embodiment, column heads 2 are installed at both ends of the column tube 1, and the structures of the two column heads 2 are the same.

The inner diameter of the sealing ring 4 is consistent with the inner diameter of the column tube 1 , and the diameter of the second cavity 213 is larger than the outer diameter of the column tube 1 .

Referring to Figures 4 and 5, the column tube 1 is a hollow structure, and its upper and lower ends are sleeved with a sealing ring 6 in the shape of a conical cone. The sealing ring 6 fits the column tube 1, and the column tube 1 is inserted into the third cavity 221, then insert the column tube 1 into the second cavity 213 of the upper part 21 of the column head, the outer side of the sealing ring 6 is inserted into the second cavity 213 along with the column tube 1, and the lower part 22 of the column head is rotated so that the second internal thread 222 and the first An external thread 214 is connected, and when the second internal thread 222 is mated with the first external thread 214, the sealing ring 6 is squeezed so that the sealing ring 6 is in close contact with the inner wall of the second cavity 213 under the action of elastic force. The upper end and the lower end of the column tube 1 are in contact with the sieve plate 3 respectively, and are closely attached to the sealing ring 4, so that the column tube 1 is fixedly connected to the upper part 21 of the column head, and effectively ensure the sealing of the chromatography column and reduce the dead volume.

The sealing ring 6 includes an upper bottom surface 61 and a lower bottom surface 62, the diameter of the upper bottom surface 61 is smaller than the diameter of the lower bottom surface 62, the diameter of the upper bottom surface 61 is consistent with the inner diameter of the column tube 1, and the diameter of the lower bottom surface 62 is consistent with the outer diameter of the column tube 1 , the diameter of the lower bottom surface 62 is greater than the diameter of the upper bottom surface 61 to effectively ensure the tight contact and compression of the sealing ring 6 and the inner wall of the second cavity 213; in one embodiment, the angle between the lower bottom surface 62 and the side of the sealing ring 6 is 30°, it can ensure that the sealing ring 6 is in close contact with the column tube 1 and the sealing ring 6 can generate a large elastic force when squeezed, thereby effectively reducing the dead volume of the chromatography column.

The column tube 1 is evenly filled with resin, and the resin constitutes the stationary phase of the visible low-pressure isotope separation chromatography column.

Referring to Fig. 6, the lower end of the joint 5 is provided with a second external thread 51, the second external thread 51 is connected with the first internal thread 212, and a through hole 52 is provided in the joint 5, and the connection shape of the lower end of the joint 5 is a hollow ring. Docking joint 7, after the sample is added by the sample injector, it flows into the docking joint 7 along the through hole 52, and then flows out to the second cavity 213 along the inner wall of the docking joint 7, and the sample passes through the sieve plate 3 in the second cavity 213 After sieving, it flows into the column tube 1 to carry out the separation process.

The column tube 1 is made of acid-resistant, alkali-resistant, flexible, and transparent materials. The column tube 1 is cylindrical in shape. In one embodiment, the column tube 1 is made of polyfluoroethylenepropylene (fluorinated ethylenepropylene, FEP) material Composition, FEP has good resistance to strong acid.

In one embodiment, the inner diameter of the column tube 1 is 3 mm, and the outer diameter of the column tube 1 is 6 mm.

Column head 2, sieve plate 3, sealing ring 4, sealing ring 6, joint 5 and butt joint 7 are all made of polytetrafluoroethylene.

The upper part 21 of the stigma and the lower part 22 of the stigma are both provided with a slot 8, and the upper part 21 of the stigma and the lower part 22 of the stigma can be rotated by turning the slot 8 with a wrench, so as to ensure the tight connection between the upper part 21 of the stigma and the lower part 22 of the stigma.

The visual low-pressure isotope separation chromatography column provided by the present invention has good tolerance to acid and alkali, and has wider application prospects in the field of low-pressure chromatography compared with traditional ion exchange columns; the column tube 1 of the present invention With good transparency characteristics, it is possible to observe the change of the stationary phase in the process of ion chromatography at any time, and improve the reliability of judging the effect of low-pressure isotope chromatography separation and purification; the present invention does not need to process threads on the column tube 1, reducing processing technology, and the length of the column tube 1 can be adjusted according to the needs, which is convenient to use; the column head 2 and the sieve plate 3 of the visual low-pressure isotope separation chromatography column provided by the present invention are separated structures, which are easy to install and clean, and are suitable for international general chromatography connector.

In this article, the orientation words such as front, rear, upper, and lower involved are defined by the parts in the drawings and the positions between the parts in the drawings, just for the clarity and convenience of expressing the technical solution. It should be understood that the use of the location words should not limit the scope of protection claimed in this application.

In the case of no conflict, the above-mentioned embodiments and features in the embodiments herein may be combined with each other.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (5)

1. The visible low-pressure isotope separation chromatographic column is characterized by comprising a column tube, a column cap, a sieve plate and a sealing ring, wherein the column cap comprises a column cap upper part, the inner wall of the column cap upper part is provided with a first cavity and a second cavity, the second cavity is communicated with the first cavity, the sieve plate is arranged in the second cavity close to the first cavity, the sealing ring is embedded in the periphery of the sieve plate, the sealing ring is tightly contacted and pressed with the inner wall of the second cavity, a sealing ring is sleeved on the column tube and is attached to the column tube, the column tube is inserted into the second cavity in the column cap upper part, the outer side of the sealing ring is inserted into the second cavity along with the column tube, the sealing ring is extruded to be tightly contacted and pressed with the inner wall of the second cavity under the action of elastic force, the column tube is contacted with the sieve plate and is tightly attached to the sealing ring, so that the column tube is fixedly connected to the column cap upper part, and the column tube is made of fluorinated ethylene propylene; the column heads are arranged at two ends of the column tube, and the two column heads have the same structure;

the column head further comprises a column head lower part, a third cavity is formed in the inner wall of the column head lower part, the column tube is inserted into the third cavity, the column head lower part can slide along the column tube, a second internal thread is arranged in the third cavity, a first external thread is arranged outside the second cavity, the second internal thread is matched and connected with the first external thread so as to connect the column head upper part with the column head lower part, and when the second internal thread is matched and connected with the first external thread, the sealing ring is extruded to realize that the sealing ring is tightly contacted and compressed with the inner wall of the second cavity;

the column cap is characterized by further comprising a joint matched with the column cap, a second external thread is arranged at the lower end of the joint, a first internal thread is arranged in a first cavity in the upper portion of the column cap, the second external thread is matched and connected with the first internal thread so as to connect the joint with the upper portion of the column cap, a through hole is formed in the joint, the lower end of the joint is connected with an abutting joint, and the joint and the abutting joint are both made of polytetrafluoroethylene materials;

the sealing ring comprises an upper bottom surface and a lower bottom surface, the diameter of the upper bottom surface is smaller than that of the lower bottom surface, the diameter of the upper bottom surface is consistent with the inner diameter of the column tube, the diameter of the lower bottom surface is consistent with the outer diameter of the column tube, and the sealing ring is in a circular truncated cone shape;

after the sample is added through the sample injector, the sample flows into the butt joint through the through hole, flows out of the inner wall of the butt joint to the second cavity, and flows into the column tube for separation after the sieve plate in the second cavity is sieved.

2. A visual low pressure isotope separation chromatically layered column in accordance with claim 1 wherein an inner diameter of said seal ring corresponds to an inner diameter of said column tube and a diameter of said second cavity is greater than an outer diameter of said column tube.

3. The visible low-pressure isotope separation chromatically-layered column of claim 1, wherein a locking groove is formed in each of the upper column head portion and the lower column head portion, and the locking groove is rotated by a wrench to rotate the upper column head portion and the lower column head portion, so that the upper column head portion and the lower column head portion can be tightly connected.

4. A visual low pressure isotope separation chromatically layered column according to claim 1, wherein said column head, said sieve plate, said seal ring, and said seal ring are all constructed of polytetrafluoroethylene material.

5. The visible low-pressure isotope separation chromatographic column in accordance with claim 1, wherein the interior of said column tube is filled with resin.

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