REACTION DEVICE FOR CHEMILUMINESCENCE DETECTOR, CHEMILUMINESCENCE DETECTOR EQUIPPED WITH SAME, AND CHEMILUMINESCENCE DETECTION METHOD

Abstract

A reaction device is provided with a reaction tube and an inert gas supply passage. The reaction tube may be composed of an alumina sintered body and configured to oxidize and reduce a sample gas therein. An inert gas is supplied into the reaction tube through the inert gas supply passage. With this, since it is possible to reduce the contamination that interferes with activation of the alumina sintered body, aging time can be shortened.

Claims

1. A reaction device adjusted for a chemiluminescence detector for detecting chemiluminescence generated in a reaction cell by a detection unit of the chemiluminescence detector, the reaction device configured to oxidize and reduce a sample gas prior to being introduced into the reaction cell, the reaction device comprising: a reaction tube made of an alumina sintered body, the reaction tube configured to oxidize and reduce the sample gas therein; and an inert gas supply passage through which an inert gas is supplied into the reaction tube.

2. The reaction device adjusted for a chemiluminescence detector as recited in claim 1, wherein the inert gas from the inert gas supply passage is supplied into the reaction tube together with an oxidizing agent.

3. The reaction device adjusted for a chemiluminescence detector as recited in claim 1, wherein the inert gas from the inert gas supply passage is supplied into the reaction tube together with a reducing agent.

4. The reaction device adjusted for a chemiluminescence detector as recited in claim 1, wherein the inert gas is nitrogen or a noble gas.

5. A chemiluminescence detector comprising: the reaction device adjusted for a chemiluminescence detector as recited in claim 1; a reaction cell into which the sample gas that has been oxidized and reduced in the reaction tube flows; and a detection unit configured to detect chemiluminescence generated in the reaction cell.

6. A chemiluminescence detection method in which a sample gas is oxidized and reduced and then introduced into a reaction cell, and chemiluminescence generated in the reaction cell is detected by a detection unit, the method comprising: supplying an oxidizing agent, a reducing agent, and an inert gas into a reaction tube composed of an alumina sintered body to oxidize and reduce the sample gas therein.

7. The chemiluminescence detection method as recited in claim 6, wherein the inert gas from the inert gas supply passage is supplied into the reaction tube together with the oxidizing agent.

8. The chemiluminescence detection method as recited in claim 6, wherein the inert gas from the inert gas supply passage is supplied into the reaction tube together with the reducing agent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a schematic view showing a configuration example of an analysis device using an SCD.

[0032] FIG. 2 is a schematic view showing a configuration example of an analysis device provided with the reaction device according to an embodiment of the present invention.

[0033] FIG. 3 is a cross-sectional view showing a configuration example of the reaction device.

[0034] FIG. 4 is a graph showing the relationship between the flow rate of the inert gas, the sensitivity of the SCD, and the selection ratio.

[0035] FIG. 5 is a graph showing the relationship between the time until the sensitivity of the SCD is stabilized and the reaching sensitivity.

[0036] FIG. 6 is a schematic view of an analysis device showing a modified example of the reaction device.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

1. Configuration of Reaction Device

[0037] FIG. 2 is a schematic view showing a configuration example of an analysis device equipped with a reaction device 21 according to an embodiment of the present invention. The configuration of the analysis device other than the reaction device 21 is the same as that shown in FIG. 1 described above, and thus the detailed description of the configuration other than the reaction device 21 is omitted.

[0038] The present embodiment differs from the configuration shown in FIG. 1 only in that an inert gas, such as, e.g., nitrogen and a noble gas, is supplied into the reaction device 21. The noble gas is exemplified by, for example, a helium gas or an argon gas. The inert gas is supplied into the reaction device 21 on the upstream side of the reaction tube 28 in the same manner as in the oxidizing agent, and is supplied to the reaction tube 28 together with the oxidizing agent.

[0039] FIG. 3 is a cross-sectional view showing a configuration example of the reaction device 21. The reaction device 21 is used for the SCD 2, which is an example of a chemiluminescence detector. That is, the reaction device 21 is used as a chemiluminescence detector for detecting the chemiluminescence generated in the reaction cell 22 with the detection unit 25 and is a reaction device for a chemiluminescence detector which oxidizes and reduces the sample gas before being introduced into the reaction cell 22.

[0040] The reaction device 21 is provided with, in addition to the reaction tube 28, the heating mechanism 29, and the joint unit 30 described with reference to FIG. 1, a main body 31, an inlet tube 32, and an outlet tube 33. The reaction tube 28, the heating mechanism 29 and the joint unit 30 are attached to the main body 31.

[0041] The main body 31 is an elongated hollow member extending in a straight line. The reaction tube 28 is attached to the main body 31 so as to extend in an inner space of the main body 31 on the same axis, and the heating mechanism 29 composed of a cylindrical heater is also attached to the main body so as to surround the outer periphery of the reaction tube 28. The reaction tube 28 has, for example, a length of 30 to 40 cm and an inner diameter of 2 to 4 mm. The joint unit 30 is attached to one end portion (upper end portion) of the main body 31 so as to communicate with the end portion of the reaction tube 28.

[0042] At the other end portion (lower end portion) of the main body 31, that is, at the end portion of the main body 31 opposite to the joint unit 30 side, an introduction passage 311 communicating with the column 11 is formed. The sample gas that has passed through the column 11 is introduced from the introduction passage 311 into the main body 31 and flows into the reaction tube 28. Further, at the lower end portion of the main body 31, in addition to the introduction passage 311, an oxidizing agent inlet passage 312 through which an oxidizing agent is supplied into the main body 31 and an inert gas supply passage 313 through which an inert gas is supplied into the main body 31 are formed. With this, the sample gas introduced into the main body 31 through the introduction passage 311 flows into the reaction tube 28 in a state in which the sample gas is mixed with the oxidizing agent flowing through the oxidizing agent inlet passage 312 and the inert gas flowing through the inert gas supply passage 313.

[0043] The heating mechanism 29 is configured to heat the reaction tube 28 from the outside to thereby heat the sample gas that has been mixed with the oxidizing agent and the inert gas flowed into the reaction tube 28. The heating mechanism 29 is configured to be heated to, for example, 800 to 1,000 C. It is configured such that a reducing agent flows into the reaction tube 28 via the inlet tube 32 and that the sample gas, the oxidizing agent, the reducing agent, and the inert gas are supplied into the reaction tube 28 to oxidize and reduce the sample gas therein.

[0044] The reaction tube 28 and the inlet tube 32 are each composed of an alumina sintered body. For the purpose of improving the compactness of the sintered body, an additive agent composed of, for example, alkali metal or alkaline earth metal is added between the crystals of alumina of the sintered body. The reaction tube 28 and the inlet tube 32 are each composed of an elongated tube extending in a straight line, and the inlet tube 32 is smaller in diameter than the reaction tube 28. A part of the inlet tube 32 is arranged in the reaction tube 28 so that one end portion (lower end portion) of the inlet tube 32 reaches the middle of the inner space of the reaction tube 28. With this, the inlet tube 32 constitutes an inner tube, and the reaction tube 28 constitutes an outer tube, so that a space is formed between the outer circumferential surface of the inlet tube 32 and the inner circumferential surface of the reaction tube 28.

[0045] The joint unit 30 is a cylindrical member made of metal, such as, e.g., stainless steel, and has a flow passage for a gas formed therein. Specifically, a sample inlet passage 301, a reducing agent inlet passage 302, an outlet passage 303, and the like are formed in the joint unit 30. The sample inlet passage 301 extends from one end portion (lower end portion) of the joint unit 30 along the axis. The reducing agent inlet passage 302 extends along the axis from the other end portion (upper end portion) of the joint unit 30 and communicates with the sample inlet passage 301 at the center portion of the joint unit 30. The outlet passage 303 extends from the outer peripheral surface of the joint unit 30 in a direction perpendicular to the axis, and communicates with the sample inlet passage 301 and the reducing agent inlet passage 302 at the central portion of the joint unit 30.

[0046] Thus, in the joint unit 30, a T-shaped flow passage is formed, which is constituted by the sample inlet passage 301, the reducing agent inlet passage 302, and the outlet passage 303. It should be noted that as long as the sample inlet passage 301, the reducing agent inlet passage 302, and the outlet passage 303 are communicated with each other in the joint unit 30, for example, they may be configured as follows. That is, the sample inlet passage 301 and the reducing agent inlet passage 302 may be configured by flow passages extending in orthogonal directions. Alternatively, the sample inlet passage 301, the reducing agent inlet passage 302, and the outlet passage 303 are not limited to be formed in a T-shape, but may be configured by flow passage of other shapes, such as, e.g., a Y-shape formed in the joint unit 30.

[0047] In the sample inlet passage 301, the end portion (upper end portion) of the reaction tube 28 opposite to the column 11 side is inserted. With this, it is configured such that the sample gas flows into the sample inlet passage 301 from the heating mechanism 29 side. An introduction member 34 is attached to the inlet of the reducing agent inlet passage 302, so that the reducing agent flows into the reducing agent inlet passage 302 through the introduction member 34. As described above, the above-mentioned one end portion (upper end portion) of the inlet tube 32 is inserted into the reducing agent inlet passage 302, and the inlet tube 32 is longer than the joint unit 30. Therefore, the other end portion (lower end portion) of the inlet tube 32 is inserted into the reaction tube 28 via the sample inlet passage 301 outside the joint unit 30. Specifically, the other end portion (lower end portion) of the inlet tube 32 is inserted into the portion of the reaction tube 28 surrounded by the heating mechanism 29.

[0048] Therefore, the reducing agent flowing into the reducing agent inlet passage 302 is supplied into the reaction tube 28 through the inlet tube 32 and mixed with the sample gas, the oxidizing agent, and the inert gas in the reaction tube 28. In the reaction tube 28, the sample gas is oxidized and reduced by reacting in a state in which the sample gas, the oxidizing agent, the reducing agent, and the inert gas are mixed. The sample gas after being oxidized and reduced flows into the sample inlet passage 301 through the space between the outer peripheral surface of the inlet tube 32 and the inner peripheral surface of the reaction tube 28.

[0049] The sample inlet passage 301 extends to the outlet passage 303 along the outer periphery of the inlet tube 32. To the outlet passage 303, the other end portion of the outlet tube 33 whose one end portion communicates with the reaction cell 22 is attached. With this configuration, the sample gas flowing into the sample inlet passage 301 after being oxidized and reduced flows out of the outlet tube 33 through the outlet passage 303.

[0050] At the inlet of the sample inlet passage 301 and the inlet of the reducing agent inlet passage 302 in the joint unit 30, a sealing member 35 and a sealing member 36 each made of graphite are provided, respectively. These sealing members 35 and 36 are so-called ferrules, and are each constituted by an annular member having a truncated conical tapered surface on the outer peripheral surface thereof

[0051] The sealing member 35 seals the gap between the inlet of the sample inlet passage 301 and one end portion (lower end portion) of the reaction tube 28. On the other hand, the sealing member 36 seals the gap between the inlet of the reducing agent inlet passage 302 and one end portion (upper end portion) of the inlet tube 32. With these sealing members 36, the airtightness in the joint unit 30 is improved, and it is possible to suppress the gas in the joint unit 30 from leaking to the outside and the outside air from flowing into the joint unit 30. At the other end portion (lower end portion) of the reaction tube 28, a sealing member 37 is provided in the same manner as in the one end portion (upper end portion) of the reaction tube 28. The sealing member 37 seals the gap between the main body 31 and the other end portion (lower end portion) of the reaction tube 28.

[0052] As described above, in this embodiment, the sample gas can be oxidized and reduced in the reaction tube 28 by supplying the oxidizing gas, the reducing agent, and the inert gas into the reaction tube 28 composed of an alumina sintered body. Therefore, even in cases where, for example, the additive agent that exists between crystals of the alumina in the sintered body reacts with the reducing agent, the emission produced at that time can be efficiently discharged by the inert gas. With this, it becomes possible to reduce the contamination that interferes with activation of the alumina sintered body, which in turn can shorten the aging time.

[0053] Especially, according to this embodiment, it becomes possible to supply the inert gas into the reaction tube 28 by utilizing the flow passage through which the oxidizing agent flows into the reaction tube 28. Therefore, the inert gas can be efficiently supplied into the reaction tube 28 with a simple configuration. Note that it is not limited to the configuration in which the inert gas is supplied into the main body 31 from a flow passage different from the oxidizing agent and mixed with the oxidizing agent before the reaction tube 28. For example, the inert gas may be supplied into the main body 31 after being mixed with the oxidizing agent in advance.

[0054] Further, in this embodiment, nitrogen with lower reactivity is supplied as the inert gas into the reaction tube 28, so that contamination that interferes with activation of the alumina sintered body can be effectively reduced. Such an effect can be similarly exhibited when using a rare gas as the inert gas.

2. Example

[0055] FIG. 4 is a graph showing the relationship between the flow rate of the inert gas, the sensitivity of the SCD 2, and the selection ratio. FIG. 4 shows the results when the temperature of the reaction tube 28 was heated to 800 C., the oxygen as the oxidizing agent was introduced at 10 mL/min, the hydrogen as the reducing agent was introduced at 80 mL/min, and nitrogen was introduced as the inert gas.

[0056] In this Example, the flow rate of the inert gas was gradually increased, then gradually decreased, and then increased again. Thus, with respect to the sensitivity of sulfur in the SCD 2 and the selection ratio of the sulfur to hydrocarbon (sensitivity of the sulfur/sensitivity of the hydrocarbon), respective temporal changes were observed. As a result, it was confirmed that the sensitivity and the selection ratio of the sulfur increased as the flow rate of the inert gas increased.

[0057] It was confirmed that when the flow rate of the inert gas was gradually reduced, the sulfur sensitivity and the selection ratio decreased although there was a time lag. Thereafter, when the flow rate of the inert gas was increased again, it was confirmed that the sensitivity and the selection ratio of the sulfur increased again.

[0058] FIG. 5 is a graph showing the relationship between the time until the sensitivity of the SCD 2 is stabilized and the reaching sensitivity. FIG. 4 shows the case in which only oxygen as the oxidizing agent was flowed into the reaction tube 28 and the case in which the oxidizing agent (oxygen) mixed with nitrogen as the inert gas was flowed into the reaction tube 28. The flow rate of the inert gas (nitrogen) mixed with the oxidizing agent was 40 mL/min.

[0059] From the results, it was confirmed that when only the oxidizing agent was flowed into the reaction tube 28, in some cases, the sensitivity of SCD 2 was not stabilized until about 80 hours have passed since the analysis device was activated. Assuming such a case, in the case of the configuration in which only the oxidizing agent is flowed into the reaction tube 28, it is necessary to set a long time exceeding 80 hours as a time until the sensitivity of the SCD 2 is stabilized (aging time).

[0060] On the other hand, when the oxidizing agent mixed with the inert gas was flowed into the reaction tube 28, although the sensitivity of the SCD 2 finally reached varied, in any of the experimental results, the sensitivity of the SCD 2 was stabilized within 15 hours. Therefore, in the case of the configuration in which the oxidizing agent mixed with the inert gas is flowed into the reaction tube 28, the aging time can be set to a short time of 15 hours or less.

3. Modified Example

[0061] FIG. 6 is a schematic view of an analysis device showing a modified example of the reaction device. The configuration of the analysis device other than the reaction device 21 is the same as that shown in FIG. 2 described above, and thus the detailed description of the configuration other than the reaction device 21 is omitted.

[0062] In this Example, it is the same as in the case shown in FIG. 1 in that an inert gas, such as, e.g., nitrogen and a noble gas, is supplied into the reaction device 21, but differs from the case shown in FIG. 1 in that an inert gas is supplied into the reaction tube 28 together with the reducing agent, not the oxidizing agent. Specifically, an inert gas supply passage 314 through which an inert gas is supplied is formed in the joint unit 30, and the reducing agent flowing into the joint unit 30 is mixed with the inert gas flowing from the inert gas supply passage 314, and then flows into the reaction tube 28. Except for this configuration, other configurations of the reaction device 21 are the same as those shown in FIG. 3.

[0063] According to such a configuration, it becomes possible to supply the inert gas into the reaction tube 28 by utilizing the flow passage through which the reducing agent flows into the reaction tube 28. Therefore, the inert gas can be efficiently supplied into the reaction tube 28 with a simple configuration. Note that it is not limited to the configuration in which the inert gas is supplied into the joint unit 30 from a flow passage different from the reducing agent and mixed with the reducing agent before the reaction tube 28. For example, the inert gas may be supplied into the joint unit 30 after being mixed with the reducing agent in advance.

DESCRIPTION OF REFERENCE SYMBOLS

[0064] 1 gas chromatograph

[0065] 2 SCD

[0066] 11 column

[0067] 12 column oven

[0068] 13 sample introduction unit

[0069] 21 reaction device

[0070] 22 reaction cell

[0071] 23 ozonizer

[0072] 24 filter

[0073] 25 detection unit

[0074] 26 pump

[0075] 27 scrubber

[0076] 28 reaction tube

[0077] 29 heating mechanism

[0078] 30 joint unit

[0079] 31 main body

[0080] 32 inlet tube

[0081] 33 outlet tube

[0082] 34 introduction member

[0083] 35 to 37 sealing member

[0084] 301 ample inlet passage

[0085] 302 reducing agent inlet passage

[0086] 303 outlet passage

[0087] 311 introduction passage

[0088] 312 oxidizing agent inlet passage

[0089] 313 inert gas supply passage

[0090] 314 inert gas supply passage