Sample vaporization chamber and gas chromatograph equipped with the sample vaporization chamber

Abstract

A gas chromatograph sample vaporization chamber (1) that has a housing (2) that houses a heater (12). An opening (18) sealed by a septum (20) is provided on an upper surface of the housing (2). A sample is: injected into an inner space (3) of the housing (2) by a syringe needle that pierces the septum (20) and is inserted into the inner space (3) from the opening (18); and heated by the heater (12) and vaporized, thereby producing sample gas. The gas chromatograph sample vaporization chamber (1) comprises: a cylindrical insert (16) having a first screw (26) provided on at least an inner circumferential surface or an outer circumferential surface on bottom end side; and an insert fixing section (4) provided in the inner space (3) of the housing (2), having a second screw that engages with the first screw (26) on the insert (16), and, by causing the first screw (26) on the insert (16) inserted into the inner space (3) from the opening (18) to engage with the second screw, fixes the insert (16) in a housed state to the inner space (3) of the housing (2).

Description

[Technical field]

[0001] The present invention relates to a sample vaporization chamber and a gas chromatograph equipped with the sample vaporization chamber. [Background technology]

[0002] A cylindrical member called an insert is generally provided inside the sample vaporizer of a gas chromatograph (see Patent Document 1). In particular, in a sample vaporizer compatible with cold on-column injection (OCI), an insert is used to accurately guide a syringe needle inserted into the sample vaporizer from above to the end of a separation column. OCI is an injection method in which the sample is directly injected into a separation column from a syringe needle that has collected the sample while the sample vaporizer is kept at a low temperature, and then the internal temperature of the sample vaporizer is rapidly raised to about 450°C to vaporize the sample injected into the separation column. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-92672 A Summary of the Invention [Problem to be solved by the invention]

[0004] The insert in the sample vaporization chamber is designed to be replaceable because it may become contaminated by the sample adhering to it. In conventional sample vaporization chambers, an O-ring is attached to the upper part of the outer circumference of the insert to fix the position of the insert and prevent the sample gas from flowing around the outside of the insert. However, since the O-ring may melt due to heating by the heater during analysis, the part of the insert above the part where the O-ring is attached is placed in a relatively low temperature area outside the heating part heated by the heater inside the sample vaporization chamber. Therefore, the sample adhering to the part of the insert placed in the relatively low temperature area is not vaporized, so the insert is easily contaminated, which causes the problem of having to replace the insert more frequently.

[0005] There are also cases where the insert is fixed inside the sample vaporization chamber using a metal spring. In such cases, since an O-ring cannot be attached to the insert, it is possible to house the entire insert inside the heating section of the sample vaporization chamber, but there is a problem in that it is not easy to remove the insert from the sample vaporization chamber when replacing it.

[0006] The present invention has been made in consideration of the above problems, and has an object to facilitate the replacement of an insert while fixing the insert in a sample vaporization chamber without using an O-ring. [Means for solving the problem]

[0007] The sample vaporization chamber of the present invention is a sample vaporization chamber for a gas chromatograph that has a housing with a built-in heater, an opening sealed by a septum is provided on the upper surface of the housing, and a sample injected into the internal space of the housing by a syringe needle that penetrates the septum and is inserted into the internal space of the housing from the opening is heated and vaporized by the heater to generate a sample gas, and is equipped with a cylindrical insert having a first thread provided on at least the inner or outer surface of the lower end side, and an insert fixing portion that has a second thread in the internal space of the housing that screws into the first thread of the insert, and that fixes the insert in a contained state in the internal space of the housing by screwing the first thread of the insert inserted into the internal space from the opening into the second thread.

[0008] The gas chromatograph of the present invention comprises the above-mentioned sample vaporization chamber, a separation column having one end fluidly connected to the internal space of the housing of the sample vaporization chamber for separating components in the sample gas generated by the sample vaporization chamber, and a detector fluidly connected to the other end of the separation column for detecting the components separated from each other by the separation column. Effect of the Invention

[0009] According to the sample vaporization chamber of the present invention, a first thread is provided on at least the inner or outer circumferential surface of the lower end side of the insert, an insert fixing part having a second thread that screws with the first thread of the insert is provided in the internal space of the housing, and the insert is fixed in a housed state in the internal space of the housing by screwing the first thread with the second thread, so that the insert can be fixed in the internal space of the housing without using an O-ring. The insert can be attached and detached from the insert fixing part simply by rotating the insert relative to the insert fixing part, so that the insert can be easily replaced.

[0010] According to the gas chromatograph of the present invention, since it is provided with the above-mentioned sample vaporization chamber in which the insert can be fixed by rotating the insert, maintenance work is easy. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view showing one embodiment of a sample vaporization chamber. [Diagram 2] FIG. 13 is a view showing the state in which the insert is removed in the embodiment. [Diagram 3] 1A and 1B are diagrams showing an example of an insert structure, in which (A) is a diagram seen from above and (B) is a diagram seen from the front. [Figure 4] 11A and 11B are diagrams showing another example of the structure of the insert, where (A) is a diagram seen from above and (B) is a diagram seen from the front. [Diagram 5] 13A and 13B are diagrams showing yet another example of the structure of the insert, where (A) is a diagram seen from above and (B) is a diagram seen from the front. [Figure 6] 13A and 13B are diagrams showing another example of an engagement structure of the insert. [Figure 7] FIG. 1 is a schematic diagram showing an embodiment of a gas chromatograph. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of a sample vaporization chamber and a gas chromatograph according to the present invention will now be described with reference to the drawings.

[0013] An embodiment of the sample vaporizer is shown in FIG.

[0014] The sample vaporization chamber 1 has a housing 2 which is a hollow metal member. An insert block 4, a heater block 6, and a carrier gas block 8 are provided in the internal space 3 of the housing 2 from the upper surface side of the housing 2. The insert block 4, heater block 6, and carrier gas block 8 are each a cylindrical metal member, and the insert block 4 is fixed to the upper end of a pipe 10 extending in the vertical direction, the carrier gas block 8 is fixed to the lower end of the pipe 10, and the heater block 6 is fixed to the middle part of the pipe 10 (between the upper and lower ends).

[0015] The upper end of the insert block 4 is exposed on the upper surface of the housing 2, and forms an opening 18 for injecting a sample from above into the internal space 3 of the housing 2 with a syringe needle for sampling. The opening 18 is sealed by a septum 20. The septum 20 is held by a septum nut 22 that is attached to the upper end of the insert block 4 by screwing. The septum nut 22 is provided with a through hole 24 for passing the syringe needle for sampling.

[0016] A metal plate 5 is attached to the outer peripheral surface of the portion of the upper end of the insert block 4 that protrudes upward from the upper surface of the housing 2, for example by welding, so as to extend horizontally, and the metal plate 5 is fixed to the upper surface of the housing 2 by bolts 25. Note that the structure for fixing the insert block 4 to the housing 2 is not limited to this. Furthermore, when the insert block 4 is firmly connected to the heater block 6 and / or the carrier gas block 8, as long as the heater block 6 and / or the carrier gas block 8 are fixed to the housing 2, the insert block 4 itself does not need to be fixed to the housing 2.

[0017] A heater 12 is wrapped around the outer circumferential surfaces of the insert block 4, heater block 6, and carrier gas block 8, and a sheet-like insulating material 14 is wrapped further outside the heater 12. The area inside the insert block 4, heater block 6, and carrier gas block 8 that is heated by the heater 12 is referred to as the heating section. Note that, although the heater 12 is depicted as a coil in FIG. 1, it may be a sheet-like heater or a heater embedded in the insert block 4, heater block 6, and carrier gas block 8.

[0018] A cylindrical insert 16 is attached to the inside of the insert block 4. In the example of FIG. 1, a first screw is provided on at least the outer peripheral surface of the lower end side of the insert 16, a second screw is provided on the inner peripheral surface of the insert block 4 to screw with the screw on the outer peripheral surface of the insert 16, and the insert 16 is fixed at a predetermined position in the housing 2 by the screwing of the first screw and the second screw. That is, the insert 16 can be attached to and detached from the insert block 4 by rotating it relative to the insert block 4. As a result, the insert 16 can be removed from the housing 2 with the septum 20 and the septum nut 22 removed, as shown in FIG. 2. The predetermined position at which the insert 16 is fixed by the insert block 4 is a position at which the entire insert 16 is accommodated in the heating unit. The insert block 4 constitutes an insert fixing unit for fixing the insert 16 at a predetermined position.

[0019] The end of the separation column 102 for gas chromatography analysis on the sample vaporization chamber 1 side is disposed so as to pass from the lower surface side of the housing 2 through the inside of the pipe 10, i.e., the inside of the carrier gas block 8 and the heater block 6, and reach the insert 16. The insert 16 is for guiding the tip of a syringe needle, which penetrates the septum 20 and is inserted into the internal space 3 of the housing 2, to an appropriate position for directly injecting a sample into the separation column 102.

[0020] In this embodiment, carrier gas for transporting the sample injected at the end of the separation column 102 is supplied to the inside of the carrier gas block 8. Septum purge gas is supplied to the space above the insert 16 in the insert block 4.

[0021] In order to facilitate the rotation of the insert 16 relative to the insert block 4, an engagement structure 28 as shown in Fig. 3 can be provided on the upper surface of the insert 16. In the example of Fig. 3, the engagement structure 28 is realized by a linear groove provided on the upper surface of the insert 16. If such an engagement structure 28 is provided, a tool such as a flat-head screwdriver can be inserted through the opening 18 of the housing 2 to rotate the insert 16, making it easy to attach and detach the insert 16 to and from the insert block 4.

[0022] In the example of Fig. 3, the first thread 26 is provided only on the lower part of the outer peripheral surface of the insert 16, but as in the example of Fig. 4, the first thread 26 may be provided on the entire outer peripheral surface of the insert 16. Also, as in the example of Fig. 5, the first thread 26 may be provided on the inner peripheral surface of the lower part of the insert 16. In this case, the insert block 4 may be provided with a structure such as a protrusion having a second thread provided on the outer peripheral surface, which is inserted into the inside of the insert 16 from below and screws into the first thread 26 of the insert 16.

[0023] The engagement structure 28 provided on the insert 16 can also be realized by a cross-shaped groove as shown in Fig. 6. Alternatively, the engagement structure 28 of the insert 16 may be any structure that allows a rod-shaped tool to be inserted through the opening 18 of the housing 2 to rotate the insert 16, and may be a structure that engages with the tip of a tool such as a hexagonal wrench.

[0024] The structure of the sample vaporization chamber 1 described above is an example, and the present invention is not limited to this. For example, in the above embodiment, the insert block 4, the heater block 6, and the carrier gas block 8 are provided as separate blocks, but they may be provided as an integrated block.

[0025] An embodiment of a gas chromatograph equipped with the above-mentioned sample vaporization chamber 1 will be described with reference to FIG.

[0026] The gas chromatograph 100 comprises a sample vaporization chamber 1, a separation column 102 for separating components in the sample gas generated by the sample vaporization chamber 1, a housing 104 for accommodating the separation column 102 therein, a detector 106 for detecting the components in the sample gas separated from each other by the separation column 102, and an injector 108 for injecting a sample into the separation column 102.

[0027] The sample vaporization chamber 1 is attached to the upper surface of the housing 104, and the detector 106 is mounted on the housing 104. One end of the separation column 102 housed inside the housing 104 extends upward to reach the insert 16 (see FIG. 1) in the sample vaporization chamber 1, and the other end of the separation column 102 is connected to the detector 106.

[0028] The injector 108 is mounted on the housing 104. The injector 108 is configured to move a sampling syringe 110 up and down above the sample vaporization chamber 1. The sample sucked into the syringe 110 is injected into the separation column 102 by being discharged from the syringe 110 to the end of the separation column 102 while the needle 112 of the syringe 110 is inserted into the sample vaporization chamber 1. After the sample is injected into the separation column 102 and the needle 112 of the syringe 110 is pulled out of the sample vaporization chamber 1, heating by the heater 12 is started, and the heating part of the sample vaporization chamber 1 is heated to about 450° C. As a result, the sample is vaporized into a sample gas, which flows through the separation column 102 and is separated into components, and is detected by the detector 106.

[0029] The embodiment described above is merely one example of the embodiment of the sample vaporization chamber and the gas chromatograph according to the present invention. The embodiment of the sample vaporization chamber and the gas chromatograph according to the present invention is as follows.

[0030] One embodiment of the sample vaporization chamber of the present invention is a sample vaporization chamber for a gas chromatograph that has a housing with a built-in heater, an opening sealed by a septum provided on the upper surface of the housing, and generates sample gas by heating and vaporizing a sample injected into the internal space of the housing by a syringe needle that penetrates the septum and is inserted into the internal space of the housing from the opening, the sample vaporization chamber comprising: a cylindrical insert having a first thread provided on at least the inner or outer surface of the lower end side; and an insert fixing portion provided in the internal space of the housing, having a second thread that screws into the first thread of the insert, and for fixing the insert in a contained state in the internal space of the housing by screwing the first thread of the insert inserted into the internal space from the opening into the second thread.

[0031] In a first aspect of one embodiment of the sample vaporization chamber according to the present invention, the insert is entirely housed in a heating section heated by the heater. With this configuration, the sample attached to the insert when the syringe needle comes into contact with the insert is also vaporized by the heat from the heater, making it difficult for the insert to be contaminated by the sample and reducing the frequency of replacing the insert.

[0032] In a second aspect of one embodiment of the sample vaporization chamber according to the present invention, the insert has the first thread on its outer peripheral surface, and the insert fixing part is a cylindrical member having the second thread on its inner peripheral surface. This simplifies the structure for fixing the insert to the insert fixing part, thereby reducing parts costs.

[0033] In a third aspect of an embodiment of the sample vaporization chamber according to the present invention, an engagement structure is provided on the upper surface of the insert, and an instrument having a structure at its tip that engages with the engagement structure is inserted from the opening into the internal space to engage with the engagement structure, and the instrument is rotated to enable attachment and detachment of the insert to and from the insert fixing part. This aspect makes it easy to attach and detach the insert to and from the insert fixing part, reducing the workload involved in replacing the insert.

[0034] One embodiment of a gas chromatograph according to the present invention has a housing, an opening sealed by a septum is provided at the top of the housing, and the above-mentioned sample vaporization chamber is provided for vaporizing a sample injected into the internal space of the housing by a syringe needle inserted through the septum and into the internal space of the housing from the opening to generate a sample gas, a separation column having one end fluidly connected to the internal space of the housing of the sample vaporization chamber for separating components in the sample gas generated by the sample vaporization chamber from each other, and a detector fluidly connected to the other end of the separation column for detecting the components separated from each other by the separation column. [Explanation of symbols]

[0035] 1 Sample vaporizer 2. Housing 3. Interior space 4 Insert Block 5. Sheet Metal 6 Heater block 8 Carrier Gas Block 10 Pipes 12 Heater 14 Insulation 16 Insert 18 Aperture 20 Septum 22 Septum nut 24 Through holes 25 Volts 26 First Screw 28 Engagement structure 100 Gas chromatograph 102 Separation column 106 Detector 108 Injector 110 Syringe 112 Needle (Syringe Needle)

Claims

1. A sample vaporization chamber for a gas chromatograph, comprising: a housing incorporating a heater; an opening sealed by a septum provided on an upper surface of the housing; and a syringe needle inserted into an internal space of the housing through the opening, the syringe needle passing through the septum, for injecting a sample into the internal space of the housing; the sample vaporization chamber being heated by the heater to generate a sample gas, the sample vaporization chamber comprising: A cylindrical insert having a first thread provided on at least an inner circumferential surface or an outer circumferential surface of a lower end side thereof; an insert fixing portion having a second screw in the internal space of the housing that screws onto the first screw of the insert, and fixing the insert in a housed state in the internal space of the housing by screwing the first screw of the insert inserted into the internal space from the opening into the second screw; A sample vaporization chamber, the heater being located on the outer periphery of the insert housed in the internal space.

2. 2. The sample vaporization chamber according to claim 1, wherein the insert is configured to be entirely contained within a heating section that is heated by the heater.

3. The insert has the first thread on an outer circumferential surface thereof, 2. The sample vaporization chamber according to claim 1, wherein the insert fixing portion is a cylindrical member having the second screw provided on an inner circumferential surface thereof.

4. The sample vaporization chamber of claim 1, wherein an engagement structure is provided on an upper surface of the insert, and the insert can be attached and detached from the insert fixing portion by inserting an instrument having a structure at its tip that engages with the engagement structure into the internal space through the opening to engage with the engagement structure and rotating the instrument.

5. a sample vaporization chamber according to claim 1, comprising a housing, an opening sealed by a septum provided in an upper portion of the housing, the sample vaporization chamber being configured to generate a sample gas by vaporizing a sample injected into the internal space of the housing by a syringe needle inserted into the internal space of the housing through the opening by penetrating the septum; a separation column having one end in fluid communication with the interior space of the housing of the sample vaporization chamber for separating components in the sample gas produced by the sample vaporization chamber from each other; a detector in fluid communication with the other end of the separation column for detecting components separated from one another by the separation column.

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