Flow path member and liquid chromatograph used in analytical device

Abstract

To provide a flow-path member with which high analysis accuracy in an analysis device can be maintained.SOLUTION: A flow-path member 10 through which a sample flows in an analysis device comprises a pipe 11 and a covering member 13 that covers the pipe 11. The pipe 11 includes: a first portion 112A including a first direction DA orthogonal to a direction D1 in which the flow-path member extends as at least an element of an advancing direction; a second portion 112B including a second direction DB opposite to the first direction DA as at least an element of an advancing direction; a first bent portion 113A in which an advancing direction changes from the first portion 112A to the second portion 112B; and a second bent portion 113B in which an advancing direction from the second portion 112B to the first portion 112A. A space 15 is formed between the covering member 13 and the pipe 11 at least in the first portion 112A and the second portion 112B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a flow path member used in an analytical device and a liquid chromatograph equipped with the flow path member. [Background technology]

[0002] In recent years, separation columns with small particle sizes have become available in liquid chromatography, resulting in sharper peaks in chromatograms than before, enabling high-resolution sample separation. Using such separation columns, excellent results can be obtained in a short time. However, extracolumn diffusion (system diffusion) has a significant impact on the theoretical plate count and peak resolution, making the diffusion performance of the system important in ultra-high-performance liquid chromatography.

[0003] In order to suppress extra-column diffusion, it is important to suppress diffusion in the piping and other components used in the device. Patent Document 1 below attempts to provide a liquid chromatograph with excellent separation performance by suppressing extra-column diffusion by reducing the internal volume of the flow path around the injection port. Another method for suppressing extra-column diffusion is to corrugate the piping. Corrugated piping can reduce the difference in flow rate between the wall and center of the piping, thereby suppressing extra-column diffusion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-276355 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the use of corrugated piping can improve the analytical accuracy of an analytical device. However, when the corrugated piping is placed in a column oven, the temperature of the sample flowing through the corrugated piping increases. This increases the sample temperature, which can lead to a decrease in the sample retention characteristics in the separation column. Thus, even when corrugated piping is used, there are factors that hinder the improvement of analytical accuracy in an analytical device.

[0006] An object of the present invention is to provide a flow path member that can maintain high analytical accuracy in an analytical device. [Means for solving the problem]

[0007] A flow path member used in an analytical device according to one aspect of the present invention is a flow path member through which a sample flows in the analytical device, and comprises a pipe and a covering member that covers the pipe, wherein the pipe has a first section that includes, as at least a component of its direction of travel, a first direction that is perpendicular to the direction in which the flow path member extends, a second section that includes, as at least a component of its direction of travel, a second direction that is opposite to the first direction, a first bend section where the direction of travel changes from the first section to the second section, and a second bend section where the direction of travel changes from the second section to the first section, and a space is formed between the covering member and the pipe at least in the first section and the second section.

[0008] The present invention is also directed to a liquid chromatograph including a flow path member used in the above-described analytical device. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a flow path member that can maintain high analytical accuracy in an analytical device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall view of a liquid chromatograph according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view showing the flow path member according to the first embodiment. [Figure 3]FIG. 2 is a side cross-sectional view of an end portion of the flow path member according to the first embodiment. [Figure 4] FIG. 10 compares chromatograms of corrugated piping with and without a coating. [Figure 5] FIG. 10 is a side cross-sectional view of an end portion of a flow path member according to a second embodiment. [Figure 6] 6 is a cross-sectional view of the flow path member shown in FIG. 5 taken along the line VI-VI. [Figure 7] FIG. 10 is a cross-sectional view of a flow path member according to a modified example of the second embodiment. [Figure 8] FIG. 10 compares chromatograms of corrugated piping with a coating and packing and corrugated piping without a coating. [Figure 9] FIG. 10 is a diagram illustrating the effect of corrugated piping. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, a flow path member and a liquid chromatograph according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] [1] First embodiment (1) Liquid chromatograph configuration 1 is a diagram showing a liquid chromatograph 1, which is an analytical device according to this embodiment. The liquid chromatograph 1 includes a solution tank 2, a liquid 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 and the separation column 50 are connected by a flow path member 10. The flow path member 10 extends into the column oven 51 and is connected to the end of the separation column 50.

[0013] The solution tank 2 stores a solvent, which is the mobile phase. The liquid delivery pump 3 pumps the solvent stored in the solution tank 2 into the analysis flow path. The autosampler 4 injects a sample into the analysis flow path. The sample injected by the autosampler 4 flows through the flow path member 10 together with the solvent and is sent to the separation column 50. In the separation column 50, the components contained in the sample are separated due to differences in the strength of interaction with the stationary phase. The components of the sample separated in the separation column 50 are detected by the detector 6.

[0014] (2) Configuration of the flow path member 10 2 is a side view of a flow path member 10 according to a first embodiment. The flow path member 10 includes a pipe 11, sleeves 12, 12 that cover both ends of the pipe 11, and a covering member 13 that covers the pipe 11 except for a portion of 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 straight in the longitudinal direction of the flow path member 10. The corrugated pipe 112 extends in a corrugated shape in the longitudinal direction of the flow path member 10. The straight pipes 111, 111 are connected to both longitudinal ends of the corrugated pipe 112.

[0015] FIG. 3 is a side cross-sectional view showing an end of the flow path member 10 according to the first embodiment. While FIG. 3 shows one end of the flow path member 10, the structure of both ends of the flow path member 10 is the same. The sleeve 12 is a cylindrical member. The straight piping 111 is disposed inside the sleeve 12. The flow path member 10 is connected to the autosampler 4 by the sleeve 12 at one end, and to the separation column 50 by the sleeve 12 at the other end. The covering member 13 covers the entire corrugated piping 112 and part of the sleeve 12. The portion of the covering member 13 covering the sleeve 12 has an expanded diameter portion 131 with an increased diameter. The covering member 13 is made of an elastic member such as a heat-shrinkable tube. For example, a polyolefin resin is used as the covering member 13.

[0016] As shown in FIG. 3 , the corrugated pipe 112 includes a first portion 112A and a second portion 112B. The first portion 112A includes at least a component of its traveling direction, which is a first direction DA perpendicular to the direction D1 in which the flow path member 10 extends. The second portion 112B includes at least a component of its traveling direction, which is a second direction DB opposite to the first direction DA. At the first bend 113A, the traveling direction of the corrugated pipe 112 changes from the first portion 112A to the second portion 112B. At the second bend 113B, the traveling direction of the corrugated pipe 112 changes from the second portion 112B to the first portion 112A. In this embodiment, the corrugated pipe 112 extends in the direction D1 while changing direction within a plane including the first direction DA and the second direction DB. Furthermore, since a large number of first bends 113A and second bends 113B are provided, the corrugated pipe 112 extends while changing its direction of travel multiple times.

[0017] FIG. 9 illustrates the effect of the corrugated piping 112. A1, A2, and A3 in the figure indicate the flow velocity of the mobile phase flowing through the corrugated piping 112, indicated by the length of the arrows. As indicated by A1, in the straight section of the piping 11, the flow velocity at the wall surface is slower than the flow velocity at the center. This difference in flow velocity causes extra-column diffusion. As indicated by A2, in the second bend 113B, vortices of the mobile phase generated inside the piping cause the flow velocity on the outside of the curve to be faster than on the inside. As indicated by A3, in the first bend 113A, vortices of the mobile phase generated inside the piping cause the flow velocity on the outside of the curve to be faster than on the inside. This configuration averages the flow velocity between the wall surface and center of the corrugated piping 112, reducing the difference in flow velocity. This reduces extra-column diffusion.

[0018] As shown in FIG. 2, the entire corrugated piping 112 is covered with a covering member 13. As a result, as shown in FIG. 3, a space 15 is formed between the corrugated piping 112 and the covering member 13. As described above, a portion of the flow path member 10 is placed in the column oven 51. The flow path member 10 placed in the column oven 51 is heated by a heater in the column oven 51. The column oven 51 is generally regulated to a high temperature, such as 40°C. However, since the space 15 is formed between the corrugated piping 112 and the covering member 13, this space 15 forms an air layer and functions as an insulating layer against the heat of the column oven 51. This makes it possible to suppress an increase in the temperature of the sample in the flow path member 10 leading to the separation column 50, thereby maintaining high separation performance in the separation column 50. In other words, it is possible to avoid a phenomenon in which the sample temperature increases and the sample components become less easily retained by the column particles. In this way, the flow path member 10 of this embodiment has the corrugated piping 112 to suppress diffusion outside the column, while forming an air layer with the covering member 13, thereby maintaining high separation performance in the separation column 50.

[0019] Moreover, since the entire area of the corrugated pipe 112 is covered with the covering member 13, it is possible to protect the corrugated pipe 112. This increases the durability of the flow path member 10. Furthermore, the covering member 13 is provided across the sleeve 12 and the first portion 112A, or the sleeve 12 and the second portion 112B. This prevents excessive bending of the sleeve 12 and the corrugated pipe 112, and prevents damage to the flow path member 10.

[0020] (3) Measurement results FIG. 4 compares the measurement results of the same sample measured under the same analytical conditions using the liquid chromatograph 1 of the first embodiment and a liquid chromatograph having corrugated piping that is not coated with a coating material. The lower chromatogram C1 in FIG. 4 shows the analysis results measured using the liquid chromatograph having corrugated piping that is not coated with a coating material. The upper chromatogram C2 in FIG. 4 shows the analysis results measured using the liquid chromatograph 1 of the first embodiment, i.e., using corrugated piping that is coated with a coating material. Peak P2 in chromatogram C2 has a longer retention time than peak P1 in chromatogram C1, indicating improved theoretical plate counts and peak resolution. It can also be seen that the peak heights of the peaks in chromatogram C2 are equal to or better than those of the peaks in chromatogram C1.

[0021] [2] Second embodiment (1) Configuration of the flow path member 10 FIG. 5 is a side cross-sectional view showing an end portion of a 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 filler member 14 is provided in a covering member 13. Except for the provision of the filler member 14, the configuration of the flow path member 10M is the same as that of the flow path member 10 shown in FIG. 2. Other configurations of the liquid chromatograph 1 are also the same as the configuration shown in FIG. 1, except for the provision of the filler member 14. As shown in FIG. 5, the filler member 14 is provided in the flow path member 10 M The filling member 14 extends straight and substantially parallel to the direction D1 in which the filling member 14 extends. The filling member 14 is, for example, a metal member.

[0022] 6 is a cross-sectional view taken along the line VI-VI of the flow path member 10M shown in FIG. 5. As shown in the figure, the filling member 14 is disposed on the side of the corrugated pipe 112. Since the filling member 14 is disposed in the space 15, the spatial volume of the space 15 is smaller than that of the first embodiment. Alternatively, as shown in FIG. 7, two filling members 14, 14 may be disposed on both sides of the corrugated pipe 112. Even This further reduces the spatial volume of the space 15.

[0023] In this way, the flow path member 10M of the second embodiment can reduce the volume of the air layer formed inside the covering member 13. In the first embodiment, an air layer is secured inside the covering member 13, thereby suppressing the temperature rise of the sample due to the heat of the column oven 51. However, users who have replaced a conventional liquid chromatograph with the liquid chromatograph 1 of the first embodiment may wish to compare the results of a particular analysis process with those of the conventional measurement under the same conditions. To meet such user needs, the flow path member 10M can be used to enable comparison with the results of the conventional measurement. Furthermore, the strength of the flow path member 10M can be improved by inserting a filler member 14 into the covering member 13.

[0024] (2) Measurement results Figure 8 compares the measurement results of the same sample measured under the same analytical conditions using the liquid chromatograph 1 of the second embodiment and a liquid chromatograph having corrugated piping that is not coated with a coating material. The chromatogram C1 in the lower part of Figure 8 shows the analysis results measured using the liquid chromatograph having corrugated piping that is not coated with a coating material. The chromatogram C3 in the upper part of Figure 8 shows the analysis results measured using the liquid chromatograph 1 of the second embodiment, i.e., using corrugated piping that is coated with a coating material and provided with a packing material. It can be seen that peak P3 in chromatogram C3 has almost the same retention time as peak P1 in chromatogram C1.

[0025] [3] Variation In the above embodiment, the first portion 112A and the second portion 112B of the corrugated pipe 112 are described as being arranged in a plane including the first direction DA and the second direction DB. However, the first portion 112A and the second portion 112B do not have to be arranged in the same plane. The first portion 112A only needs to include the first direction DA as at least a component of its traveling direction, and the second portion 112B only needs to include the second direction DB as at least a component of its traveling direction.

[0026] In the present embodiment, space 15 is formed not only on the outer peripheries of first portion 112A and second portion 112B, but also on the outer peripheries of first bent portion 113A and second bent portion 113B. That is, in Fig. 3, space 15 is formed on the first direction DA side of first bent portion 113A and on the second direction DB side of second bent portion 113B. However, this is just one example, and it is sufficient that space 15 is formed at least on the outer peripheries of first portion 112A and second portion 112B.

[0027] In the second embodiment, the filling member 14 is described as a rod member having a substantially circular cross section. This is just an example, and the cross-sectional shape of the filling member 14 may be other shapes. For example, On the surface By making the shape similar to that of the air gap, it is possible to further reduce the volume of the air gap.

[0028] [4] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0029] (Section 1) The flow path member used in the analysis device according to one embodiment includes: A flow path member through which a sample flows in an analytical device, Piping and a covering member that covers the piping; Equipped with The piping is a first portion including a first direction perpendicular to the extending direction of the flow path member as at least a component of the traveling direction; a second part including a second direction opposite to the first direction as at least a component of the traveling direction; a first bend portion where the traveling direction changes from the first portion to the second portion; a second bend portion where the traveling direction changes from the second portion to the first portion; and A space is formed between the covering member and the piping at least in the first portion and the second portion.

[0030] It is possible to provide a flow path member that can maintain high analytical accuracy in an analytical device.

[0031] (Section 2) A flow path member used in the analyzer according to claim 1, the analytical instrument includes an autosampler and a separation column; The flow path member may connect the autosampler and the separation column.

[0032] Extra-column diffusion in the flow path between the autosampler and the separation column can be reduced.

[0033] (Section 3) A flow path member used in the analyzer according to claim 2, The end of the flow path member connected to the separation column may be placed in a column oven.

[0034] The space formed inside the covering member functions as a heat insulating layer, and can reduce the temperature rise of the sample caused by the heat of the column oven.

[0035] (Section 4) A flow path member used in the analyzer according to any one of items 1 to 3, The covering member may be made of an elastic member.

[0036] The covering member can be attached to match the shape of the flow path member.

[0037] (Section 5) A flow path member used in the analyzer according to claim 4, A sleeve having a diameter larger than the first and second parts may be provided at the end of the pipe, and the covering member may be provided across the sleeve and the first part, or the sleeve and the second part.

[0038] This prevents the piping from being excessively bent relative to the sleeve, thereby improving the durability of the flow path member.

[0039] (Section 6) A flow path member used in the analyzer according to any one of items 1 to 5, A filling member for reducing the volume of the space may be disposed inside the covering member.

[0040] It becomes easy to compare the analysis results obtained by an analysis device equipped with this flow path member with the analysis results obtained by a conventional analysis device.

[0041] (Section 7) A flow path member used in the analyzer according to claim 6, The filling member may be a rod member extending substantially parallel to the direction in which the flow path member extends.

[0042] A filler member can be inserted along the flow path member.

[0043] (Section 8) A liquid chromatograph according to another aspect of the present invention includes a flow path member used in the analyzer according to any one of the first to seventh aspects. [Explanation of symbols]

[0044] 1...liquid chromatograph, 4...autosampler, 5...column unit, 50...separation column, 51...column oven, 10...flow path member, 11...piping, 111...straight piping, 112...corrugated piping, 112A...first part, 112B...second part, 113A...first bend, 113B...second bend, 12...sleeve, 13...covering member, 131...expanded diameter portion, 14...filler member, 15...space

Claims

1. A flow path member through which a sample flows in an analytical device, Piping and a covering member that covers the piping; Equipped with The piping is a first portion including a first direction perpendicular to the extending direction of the flow path member as at least a component of a traveling direction; a second part including a second direction opposite to the first direction as at least a component of the traveling direction; a first bend portion where a traveling direction changes from the first portion to the second portion; a second bend portion where a traveling direction changes from the second portion to the first portion; and a portion of the flow path member is installed in a column oven; A flow path member used in an analytical device, wherein an air layer is formed by leaving a gap between the first portion, the second portion, the first bend portion, and the second bend portion and the covering member, and a space that functions as an insulating layer against the heat of the column oven is formed.

2. the analytical instrument includes an autosampler and a separation column; The flow path member used in the analyzer according to claim 1 , wherein the flow path member connects the autosampler and the separation column.

3. The flow path member used in the analyzer according to claim 2 , wherein an end of the flow path member connected to the separation column is disposed within the column oven.

4. The flow path member used in the analyzer according to any one of claims 1 to 3, wherein the covering member is made of an elastic material.

5. 5. A flow path member used in an analytical device according to claim 4, wherein a sleeve having a diameter larger than that of the first and second portions is provided at an end of the piping, and the covering member is provided across the sleeve and the first portion or across the sleeve and the second portion.

6. 6. The flow path member used in the analyzer according to claim 1, wherein a filling member for reducing the volume of the space is disposed inside the covering member.

7. The flow path member used in the analyzer according to claim 6 , wherein the filling member is a rod member extending substantially parallel to the direction in which the flow path member extends.

8. A liquid chromatograph comprising a flow path member used in the analyzer according to any one of claims 1 to 7.

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