Flow path member for analysis device and liquid chromatograph

Abstract

This invention provides a flow path component for an analytical apparatus and a liquid chromatograph including said flow path component, which can maintain a high level of analytical accuracy. The flow path component for sample flow in the analytical apparatus includes tubing and a covering component covering the tubing. The tubing has: a first portion including a first direction orthogonal to the direction in which the flow path component extends as at least a direction of travel; a second portion including a second direction opposite to the first direction as at least a direction of travel; a first bend where the direction of travel changes from the first portion to the second portion; and a second bend where the direction of travel changes from the second portion to the first portion. A space is formed between the covering component and the tubing, at least in the first portion and the second portion.

Description

Technical Field

[0001] The present invention relates to a flow path component for an analytical apparatus and a liquid chromatograph including said flow path component. Background Technology

[0002] In recent years, small-particle-size separation columns have emerged for liquid chromatography, resulting in sharper peaks in chromatograms and enabling high-resolution sample separation. Using such columns, a large number of highly resolved results can be obtained in a short time. However, on the other hand, extra-column diffusion (systemic diffusion) has a greater impact on theoretical plate number or peak resolution. Therefore, the diffusion performance of the system is of great importance in ultra-high performance liquid chromatography (UHPLC).

[0003] To suppress extra-column diffusion, it is important to suppress diffusion in the piping and other components of the instrument. Japanese Patent Application Publication No. 2009-276355 describes an attempt to suppress extra-column diffusion by reducing the internal volume of the flow path around the injection port, thereby providing a liquid chromatograph with excellent separation performance. Another method for suppressing extra-column diffusion is to make the piping corrugated. In corrugated piping, the flow rate difference between the pipe wall and the center can be suppressed, thereby suppressing extra-column diffusion. Summary of the Invention

[0004] Using corrugated piping as described above can improve the analytical accuracy of the analytical apparatus. However, when corrugated piping is placed inside a column oven, the temperature of the sample flowing through it rises. This temperature rise can lead to a decrease in the sample retention characteristics within the separation column. Therefore, even with corrugated piping, there are factors that hinder the improvement of the analytical accuracy of the apparatus.

[0005] The purpose of this invention is to provide a flow path component that can maintain the analytical accuracy of an analytical device to a high degree.

[0006] According to one aspect of the invention, a flow path component for an analytical apparatus is a flow path component for supplying sample flow in an analytical apparatus, the flow path component comprising a pipe and a covering component covering the pipe, the pipe having: a first portion including a first direction orthogonal to the direction in which the flow path component extends as a component of at least a direction of travel; a second portion including a second direction opposite to the first direction as a component of at least a direction of travel; a first bend where the direction of travel changes from the first portion to the second portion; and a second bend where the direction of travel changes from the second portion to the first portion, a space being formed between the covering component and the pipe, at least in the first portion and the second portion.

[0007] Furthermore, the present invention also relates to a liquid chromatograph including the flow path components for the analytical apparatus described above. Attached Figure Description

[0008] Figure 1 This is an overall diagram of the liquid chromatograph of this embodiment.

[0009] Figure 2 This is a side view showing the flow path component of the first embodiment.

[0010] Figure 3 This is a side cross-sectional view of the end of the flow path component in the first embodiment.

[0011] Figure 4 This is a chromatogram comparing corrugated piping with and without a covering component.

[0012] Figure 5 This is a side cross-sectional view of the end of the flow path component in the second embodiment.

[0013] Figure 6 yes Figure 5 The diagram shows the VI-VI cross-sectional view of the flow path component.

[0014] Figure 7 This is a cross-sectional view of the flow path component of a modified embodiment of the second embodiment.

[0015] Figure 8 This is a chromatogram comparing the corrugated pipes with and without covering components and corrugated pipes without covering components.

[0016] Figure 9 This is a diagram illustrating the effect of waveform piping. Detailed Implementation

[0017] Next, the flow path components and liquid chromatograph of the embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] [1] First implementation method

[0019] (1) Structure of a liquid chromatograph

[0020] Figure 1 This diagram shows a liquid chromatograph 1, which is the analytical apparatus of this embodiment. The liquid chromatograph 1 includes a solution tank 2, a delivery pump 3, an autosampler 4, a column unit 5, and a detector 6. The column unit 5 includes a separation column 50 and a column oven 51. The autosampler 4 is connected to the separation column 50 via a flow path member 10. The flow path member 10 extends within the column oven 51 and is connected to the end of the separation column 50.

[0021] Solution tank 2 stores the solvent as the mobile phase. Pump 3 pressurizes the solvent stored in solution tank 2 into the analytical flow path. Automatic sampler 4 injects the sample into the analytical flow path. The sample injected into automatic sampler 4 flows together with the solvent within flow path component 10 and is sent to separation column 50. In separation column 50, the components contained in the sample are separated according to the different magnitudes of the interactions between the stationary phases. Detector 6 detects the components of the sample separated in separation column 50.

[0022] (2) Structure of flow path component 10

[0023] Figure 2 This is a side view of the flow path component 10 according to the first embodiment. The flow path component 10 includes a pipe 11, a sleeve 12 covering both ends of the pipe 11, the sleeve 12, and a covering component 13 covering the pipe 11 except for a portion at both ends. The pipe 11 includes a straight pipe 111 and a corrugated pipe 112. The straight pipe 111 is provided at both ends of the pipe 11 and extends in a straight line along the long side direction of the flow path component 10. The corrugated pipe 112 extends in a corrugated shape along the long side direction of the flow path component 10. The straight pipe 111 is connected to both ends of the corrugated pipe 112 in the long side direction.

[0024] Figure 3 This is a side cross-sectional view showing the end of the flow path member 10 in the first embodiment. Figure 3 The end of one side of the flow path member 10 is shown, but the structures of both ends of the flow path member 10 are identical. The sleeve 12 is a cylindrical member. A straight conduit 111 is disposed inside the sleeve 12. The flow path member 10 is connected to the automatic sampler 4 via the sleeve 12 at one end and to the separation column 50 via the sleeve 12 at the other end. A covering member 13 covers the entire area of ​​the corrugated conduit 112 and a portion of the sleeve 12. An enlarged diameter portion 131 is formed in the portion of the sleeve 12 covered by the covering member 13. The covering member 13 includes an elastic member such as a heat-shrinkable tube. For example, polyolefin resin is used as the covering member 13.

[0025] like Figure 3As shown, the corrugated pipe 112 includes a first portion 112A and a second portion 112B. The first portion 112A includes a first direction DA orthogonal to the direction D1 extending from the flow path member 10 as a component of at least the travel direction. The second portion 112B includes a second direction DB opposite to the first direction DA as a component of at least the travel direction. At the first bend 113A, the travel direction of the corrugated pipe 112 changes from the first portion 112A to the second portion 112B. At the second bend 113B, the travel direction of the corrugated pipe 112 changes from the second portion 112B to the first portion 112A. In this embodiment, the corrugated pipe 112 changes direction and extends toward direction D1 in a plane including the first direction DA and the second direction DB. Furthermore, since multiple first bends 113A and second bends 113B are provided, the corrugated pipe 112 changes its travel direction and extends multiple times.

[0026] Figure 9 This diagram illustrates the effect of the corrugated piping 112. In the diagram, A1, A2, and A3 represent the flow velocities of the flowing phase in the corrugated piping 112, indicated by the length of the arrows. As shown in A1, in the straight section of the piping 112, the flow velocity at the wall is slower than that at the center. This velocity difference is the cause of external diffusion. As shown in A2, at the second bend 113B, due to the vortices of the flowing phase generated inside the piping, the flow velocity on the outside of the bend is faster than that on the inside. As shown in A3, at the first bend 113A, due to the vortices of the flowing phase generated inside the piping, the flow velocity on the outside of the bend is faster than that on the inside. With this structure, the flow velocities at the wall and center of the corrugated piping 112 are averaged, and the velocity difference is reduced. This suppresses external diffusion.

[0027] like Figure 2 As shown, the entire area of ​​the corrugated piping 112 is covered by the covering member 13. Thus, as... Figure 3 As shown, a space 15 is formed between the corrugated piping 112 and the covering member 13. As described, a portion of the flow path member 10 is disposed in the column oven 51. The flow path member 10 disposed in the column oven 51 is heated by the heater of the column oven 51. The column oven 51 is generally heated to a high temperature, for example, 40 degrees Celsius. However, since a space 15 is formed between the corrugated piping 112 and the covering member 13, the space 15 forms an air layer, which functions as a heat insulation layer relative to the heat of the column oven 51. As a result, the temperature rise of the sample in the flow path member 10 reaching the separation column 50 can be suppressed, thereby maintaining the separation performance of the separation column 50 at a high level. That is, the phenomenon that the sample composition is difficult to retain by the column particles due to the temperature rise of the sample can be avoided. Thus, the flow path member 10 of this embodiment suppresses extra-column diffusion by having the corrugated piping 112 and maintains the separation performance of the separation column 50 at a high level by forming an air layer by the covering member 13.

[0028] Furthermore, since the entire area of ​​the corrugated pipe 112 is covered by the covering member 13, the corrugated pipe 112 is protected. This improves the durability of the flow path member 10. Additionally, the covering member 13 is provided across the sleeve 12 and the first part 112A, or the sleeve 12 and the second part 112B. This prevents excessive bending of the sleeve 12 and the corrugated pipe 112, thereby preventing damage to the flow path member 10.

[0029] (3) Measurement results

[0030] Figure 4 This is a graph comparing the measurement results obtained by measuring the same sample under the same analytical conditions in the liquid chromatograph 1 of the first embodiment and the liquid chromatograph with waveform tubing that is not covered by the covering component. Figure 4 The chromatogram C1 on the lower side represents the analytical result obtained by determination in a liquid chromatograph with waveform tubing that is not covered by the covering component. Figure 4 Chromatogram C2 on the upper side represents the analytical results obtained using the liquid chromatograph 1 of the first embodiment, i.e., using the waveform tubing covered by the coating member. It can be seen that peak P2 in chromatograph C2 has a longer retention time than peak P1 in chromatograph C1, resulting in improved theoretical plate number and peak resolution. Furthermore, it can be seen that the peak heights of each peak in chromatograph C2 are equal to or higher than those of each peak in chromatograph C1.

[0031] [2] Second implementation method

[0032] (1) Structure of flow path component 10

[0033] Figure 5 This is a side cross-sectional view showing the end of the flow path member 10M according to the second embodiment. The flow path member 10M of the second embodiment differs from the flow path member 10 of the first embodiment in that a filling member 14 is provided in the covering member 13. Except for the filling member 14, the structure of the flow path member 10M is similar to... Figure 2 The flow path component 10 shown is the same. Except for the packing component 14, the other structures of the liquid chromatograph 1 are also the same. Figure 1 The structures shown are the same. For example... Figure 5 As shown, the filling member 14 extends in a straight line, approximately parallel to the direction D1 of the flow path member 10M. The filling member 14 is, for example, a metal member.

[0034] Figure 6 yes Figure 5 The diagram shows a cross-sectional view along line VI-VI of the flow path component 10M. As shown, the filling member 14 is disposed on the side of the corrugated pipe 112. Because the filling member 14 is disposed within the space 15, the volume of the space 15 is smaller compared to the first embodiment. Alternatively, as... Figure 7 As shown, two filling members 14, 14 can also be arranged on both sides of the corrugated pipe 112. As a result, the volume of space 15 becomes smaller.

[0035] Thus, the flow path member 10M of the second embodiment can reduce the volume of the air layer formed inside the coating member 13. In the first embodiment, an air layer is ensured inside the coating member 13, thereby suppressing the temperature rise of the sample due to the heat of the column oven 51. However, users who replace their apparatus with the liquid chromatograph 1 of the first embodiment may require comparisons under the same conditions as previous measurements in certain specific analytical processes. Therefore, by using the flow path member 10M, comparisons with previous measurements can be made to meet such user requirements. In addition, the strength of the flow path member 10M can be increased by inserting the packing member 14 into the coating member 13.

[0036] (2) Measurement results

[0037] Figure 8 This is a graph comparing the measurement results obtained by measuring the same sample under the same analytical conditions in the liquid chromatograph 1 of the second embodiment and the liquid chromatograph with waveform tubing that is not covered by the covering component. Figure 8 The chromatogram C1 on the lower side represents the analytical result obtained by determination in a liquid chromatograph with waveform tubing that is not covered by the covering component. Figure 8 Chromatogram C3 on the upper side represents the analytical result obtained using the liquid chromatograph 1 of the second embodiment, i.e., using a waveform tubing covered by a coating member and equipped with a packing member. It can be seen that the retention time of peak P3 in chromatograph C3 is almost equal to that of peak P1 in chromatograph C1.

[0038] [3] Variations

[0039] In the described embodiment, the case where the first part 112A and the second part 112B of the waveform piping 112 are arranged in a plane containing the first direction DA and the second direction DB is used as an example. However, the first part 112A and the second part 112B may not be arranged in the same plane. The first part 112A only needs to include the first direction DA as a component of at least the travel direction, and the second part 112B only needs to include the second direction DB as a component of at least the travel direction.

[0040] In this embodiment, the space 15 is formed not only on the outer periphery of the first portion 112A and the second portion 112B, but also on the outer periphery of the first curved portion 113A and the second curved portion 113B. That is, in Figure 3In this case, a space 15 is formed on the first direction DA side relative to the first curved portion 113A, and a space 15 is also formed on the second direction DB side relative to the second curved portion 113B. However, this is just one example; it is sufficient that spaces 15 are formed at least on the outer periphery of the first portion 112A and the second portion 112B.

[0041] In the second embodiment, the case where the filling member 14 is a rod member with a generally circular cross-section will be described as an example. This is just one example; the cross-sectional shape of the filling member 14 can also be other shapes. For example, by forming a shape that approximates the cross-section of space 15, the volume of the air layer can be further reduced.

[0042] [4] Morphology

[0043] Those skilled in the art will understand that the various exemplary embodiments are specific examples of the following forms.

[0044] (First item)

[0045] A flow path component in an analytical apparatus is a flow path component that supplies the flow of the sample within the analytical apparatus.

[0046] The flow path components include:

[0047] Piping; and

[0048] Covering component, covering the piping,

[0049] The piping has:

[0050] The first part includes a first direction orthogonal to the direction in which the flow path member extends, as a component of at least the direction of travel;

[0051] The second part includes a component of the direction opposite to the first direction, namely the second direction, as at least the direction of travel;

[0052] The first curved section changes its direction of travel from the first section to the second section; and

[0053] The second curved section changes its direction of travel from the second section to the first section.

[0054] A space is formed between the covering member and the piping, at least in the first part and the second part.

[0055] Flow path components can be provided to maintain the analytical accuracy of the analytical device at a high level.

[0056] (Second item)

[0057] According to the flow path component for the analysis device described in the first item, wherein

[0058] The analytical apparatus may include an automated sampler and a separation column.

[0059] The flow path component can connect the automatic sampler and the separation column.

[0060] It can reduce extra-column diffusion in the flow path between the automatic sampler and the separation column.

[0061] (Third item)

[0062] According to the flow path component for the analysis device described in the second item, wherein

[0063] The end of the flow path component that connects to the separation column can also be located inside the column temperature chamber.

[0064] The space formed inside the covering component functions as a heat insulation layer, which can reduce the temperature rise of the sample due to the heat of the column oven.

[0065] (Item 4)

[0066] The flow path component for the analytical apparatus according to any one of the first to third items, wherein

[0067] The covering component may also include an elastic component.

[0068] The covering component can be installed according to the shape of the flow path component.

[0069] (Item 5)

[0070] According to the flow path component for the analysis device described in the fourth item, wherein

[0071] Alternatively, a sleeve with a diameter larger than the first part and the second part may be provided at the end of the piping, and the covering member may be provided across the sleeve and the first part, or the sleeve and the second part.

[0072] It can prevent the piping from bending excessively relative to the sleeve, thereby improving the durability of the flow path components.

[0073] (Item 6)

[0074] The flow path component for the analytical apparatus according to any one of items 1 to 5, wherein

[0075] A filling member for reducing the volume of the space may also be disposed inside the covering member.

[0076] It is easy to compare the analysis results of the analysis device including the flow path component with the analysis results obtained from previous analysis devices.

[0077] (Seventh item)

[0078] According to the flow path component for the analysis device described in item six, wherein

[0079] The filling member may also be a rod member that extends substantially parallel to the direction in which the flow path member extends.

[0080] Filling components can be inserted along the flow path components.

[0081] (Item 8)

[0082] Another embodiment of the liquid chromatograph of the present invention includes a flow path component for an analytical apparatus according to any one of claims 1 to 7.

Claims

1. A flow path component for an analytical apparatus, characterized in that, It is a flow path component in the analytical apparatus that supplies the flow of the sample. The flow path components include: Piping; and Covering component, covering the piping, The piping has: The first part includes a first direction orthogonal to the direction in which the flow path member extends, as a component of at least the direction of travel; The second part includes a component of the direction opposite to the first direction, namely the second direction, as at least the direction of travel; The first curved section changes its direction of travel from the first section to the second section; and The second curved section changes its direction of travel from the second section to the first section. A portion of the flow path component is disposed within the column temperature chamber, and a space is formed between the covering component and the piping, at least in the first portion, the second portion, the first bend portion, and the second bend portion. The first part, the second part, the first curved part, and the second curved part are spaced apart from the covering member. The space forms an air layer, which functions as a heat insulation layer relative to the heat of the column temperature chamber.

2. The flow path component for an analytical apparatus according to claim 1, wherein the analytical apparatus comprises an autosampler and a separation column. The flow path component connects the automatic sampler and the separation column.

3. The flow path component for an analytical apparatus according to claim 2, wherein the end of the flow path component connected to the separation column is disposed within the column oven.

4. The flow path component for an analytical apparatus according to any one of claims 1 to 3, wherein the covering component comprises an elastic component.

5. The flow path component for an analytical apparatus according to claim 4, wherein a sleeve with a diameter larger than the first portion and the second portion is provided at the end of the piping, and the covering component is provided across the sleeve and the first portion, or the sleeve and the second portion.

6. The flow path component for an analytical apparatus according to any one of claims 1 to 3, wherein a filling component for reducing the volume of the space is disposed inside the covering component.

7. The flow path component for an analytical apparatus according to claim 6, wherein the filling component is a rod component extending substantially parallel to the direction in which the flow path component extends.

8. A liquid chromatograph, characterized in that, Includes flow path components for an analysis apparatus according to any one of claims 1 to 3.

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