Analysis system

Abstract

The invention provides an analysis system. Comprising an oxygenolysis device having an inlet and an outlet from which a sample introduced from the inlet is allowed to flow out after oxygenolysis, the oxygenolysis device comprising: a reaction tube having one end and the other end, the one end being disposed on the inlet side and the other end being disposed on the outlet side; the reaction tube is used for oxygenolysis of a sample inside; a heating furnace in which the reaction tube is housed and which heats the reaction tube; an oxidizing gas supply unit that supplies an oxidizing gas for oxidizing the sample; a make-up gas supply unit that supplies a make-up gas as an inert gas that does not affect oxidative decomposition of the sample; and an interface part having a structure for introducing the oxidizing gas supplied from the oxidizing gas supply part and the make-up gas supplied from the make-up gas supply part into the reaction tube together with the sample introduced from the inlet.

Description

Technical Field

[0001] The present invention relates to an analysis system including an oxidative decomposition device for performing oxidative decomposition of a sample. Background Art

[0002] In the past, a method of carrying out a process containing oxygen components (such as 16 A method for detecting and quantifying the oxygen content in a sample containing oxygen isotopes (e.g., 18 O) is used to oxidize and decompose the sample, and the composition obtained by the oxidative decomposition is analyzed by a mass spectrometer or the like. Thus, if the oxygen component in the composition analyzed by the mass spectrometer or the like is 16 O can be identified as originating from the sample, if 18 O can be identified as being derived from oxidizing gas.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-508711 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In order to implement the above method, it is necessary to pass the sample and the oxidizing gas through a reaction tube heated to a high temperature (e.g., about 600°C to 1000°C) to perform complete oxidative decomposition of the sample. Therefore, as the material of the reaction tube, a material with high heat resistance must be used. As a material with high heat resistance, ceramic materials such as alumina are considered. However, it is known from experiments that when an alumina reaction tube is used for oxidative decomposition, as the heating temperature of the reaction tube increases, the proportion of the composition after oxidative decomposition changes. For example, when the heating temperature of the reaction tube is changed and the C 16 O2 (m / z = 44) relative to C 18 O 16 O (m / z = 46), it can be seen that as the heating temperature of the reaction tube increases, C 16 The proportion of O2 increases (ref. Figure 5 ). It is speculated that by using 18 Oxidation of the oxidizing gas to generate C 18 O 16 O changes to C for some reason 16When the analysis described in the background art is performed under such circumstances, it is impossible to accurately distinguish whether the oxygen component in the composition detected by a mass spectrometer or the like is derived from the sample or the oxidizing gas.

[0008] Therefore, an object of the present invention is to provide an analysis system that improves the accuracy of detection and quantification in a method for detecting and quantifying the oxygen component in a sample by oxidatively decomposing the sample using an oxidizing gas containing oxygen isotopes whose combination and distribution are different from those of natural oxygen and detecting the composition obtained by the oxidative decomposition.

[0009] Solutions for solving problems

[0010] For the above 18 O 16 O becomes C 16 The causes of O2 were studied in depth and the following insights were obtained: 18 O 16 During the passage of O through the reaction tube, the raw material of the reaction tube, alumina (Al2O3), contained 16 O and C 18 O 16 O 18 Substitution of O. Based on such findings, the following analysis system was invented.

[0011] That is, the analysis system of the present invention comprises: an oxidation decomposition device having an inlet and an outlet, wherein a sample introduced from the inlet is oxidatively decomposed and then flows out from the outlet; and a detector for detecting an oxidation reaction product obtained by oxidation decomposition by the oxidation decomposition device, wherein the analysis system is used to detect and / or quantify a compound containing a specific oxygen component in the sample, wherein:

[0012] The oxidative decomposition device comprises:

[0013] A reaction tube having one end and another end, wherein the one end is arranged at the inlet side and the other end is arranged at the outlet side, and the reaction tube is used for performing oxidative decomposition of the sample inside;

[0014] a heating furnace, which accommodates the reaction tube inside and is used to heat the reaction tube;

[0015] an oxidizing gas supply unit that supplies an oxidizing gas for oxidizing the sample, the oxidizing gas containing an oxygen component having an isotope different from the specific oxygen component;

[0016] a supplementary gas supply unit that supplies a supplementary gas that is an inert gas that does not affect oxidative decomposition of the sample; and

[0017] The interface portion has a structure for introducing the oxidizing gas supplied from the oxidizing gas supply portion and the supplementary gas supplied from the supplementary gas supply portion into the inner side of the reaction tube together with the sample introduced from the inlet.

[0018] Effects of the Invention

[0019] According to the analysis system of the present invention, since the interface of the oxidative decomposition device has a structure for introducing the oxidative gas and the supplementary gas into the inner side of the reaction tube together with the sample introduced from the inlet, the contact opportunity between the oxidatively decomposed composition in the reaction tube and the inner surface of the reaction tube is limited, and the amount of the raw materials in the reaction tube is suppressed. 16 O and the oxygen isotopes contained in the composition after oxidative decomposition ( 18 O. 17 Thus, the accuracy of detection and quantification is improved when a method is implemented in which the oxygen component in the sample is detected and quantified by oxidizing and decomposing the sample using an oxidizing gas containing oxygen isotopes whose combination and distribution are different from those of natural oxygen and detecting the composition obtained by the oxidative decomposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow path configuration diagram of a GC-COMB-MS mode of an example of an analysis system.

[0021] Figure 2 It is a flow path structure diagram of the GC-MS mode of this embodiment.

[0022] Figure 3 This is a cross-sectional view showing an example of the structure of the oxidative decomposition device of this embodiment.

[0023] Figure 4 This is a graph showing the verification result of the correlation between the 44 / 46 ratio of 18-methanol and the heating furnace temperature in the GC-Comb-MS mode of this example.

[0024] Figure 5 This is a graph showing the verification result of the correlation between the 44 / 46 ratio of 18-methanol and the heating furnace temperature in the GC-Comb-MS mode when no make-up gas is used in the oxidative decomposition device.

[0025] Figure 6 This is a graph showing the correlation between the change in the outlet pressure of the reaction tube and the length of the resistance tube when the GC-MS mode is switched to the GC-Comb-MS mode in this example.

[0026] Figure 7This is a graph showing the correlation between the change in the baseline of the detector signal of the mass spectrometer and the length of the resistance tube when the GC-MS mode is switched to the GC-Comb-MS mode in this embodiment. DETAILED DESCRIPTION

[0027] Hereinafter, an analysis system according to an embodiment of the present invention will be described with reference to the drawings.

[0028] like Figure 1 and Figure 2 As shown, the analysis system 1 mainly includes a sample vaporization chamber 2, a separation column 4, an oxidation decomposition device 6, a mass spectrometer 8, and a switching valve 10. The sample vaporization chamber 2 and the separation column 4 constitute a gas chromatograph, which vaporizes the injected sample in the sample vaporization chamber 2 and introduces it into the separation column 4 together with the carrier gas, and separates the components in the sample from each other in the separation column 4. The gas chromatograph composed of the sample vaporization chamber 2 and the separation column 4 constitutes a sample supply device for supplying the sample to the oxidation decomposition device 6.

[0029] The switching valve 10 has ports 1 to 6, and is capable of being placed in a position where fluid is communicated between ports 1 and 6, between ports 2 and 3, and between ports 4 and 5. Figure 1 and a position that enables fluid communication between ports 1 and 2, between ports 3 and 4, and between ports 5 and 6 ( Figure 2 Two-position valve with these two positions).

[0030] The fluid at port No. 1 of the switching valve 10 is connected to a flow path 16 communicating with the inlet of the mass spectrometer 8, the fluid at port No. 2 is connected to the downstream end of the separation column 4, the fluid at port No. 3 is connected to an inlet flow path 12 communicating with the oxidation decomposition device 6, the port No. 4 is closed, the fluid at port No. 5 is connected to a pressure reducing flow path 22, and the fluid at port No. 6 is connected to an outlet flow path 14 communicating with the outlet of the oxidation decomposition device 6.

[0031] The switching valve 10 is a switching mechanism for switching the gas chromatograph and mass spectrometer 8 composed of the sample vaporization chamber 2 and the separation column 4 to either a GC-MS mode (first state) in which the oxidative decomposition device 6 is not fluidly connected between them, or a GC-Comb-MS mode (second state) in which the oxidative decomposition device 6 is fluidly connected between them. Figure 1 The flow path structure in GC-Comb-MS mode is shown. Figure 2 The flow path structure in GC-MS mode is shown.

[0032] The oxidative decomposition device 6 includes a heating furnace 28 , a reaction tube 30 , an interface portion 32 , an outlet adapter 34 , an oxidative gas supply portion 36 , and a make-up gas supply portion 38 .

[0033] The reaction tube 30 has at least an inner surface made of aluminum oxide or the like. 16 The reaction tube 30 is a highly heat-resistant round tube-shaped member formed of an oxide of O. The reaction tube 30 is housed inside the heating furnace 28 so as to penetrate the heating furnace 28, and is used to perform oxidative decomposition of the sample inside. The heating furnace 28 heats the reaction tube 30 housed inside to a set temperature.

[0034] The interface portion 32 is provided at one end side (left side in the figure) of the reaction tube 30. The interface portion 32 has an inlet 33 to which the downstream end of the inlet channel 12 is fluidically connected.

[0035] The outlet-side adapter 34 is provided at the other end side (right side in the figure) of the reaction tube 30 , and is used to connect the upstream end of the outlet flow channel 14 to the other end of the reaction tube 30 .

[0036] The oxidizing gas supply unit 36 ​​is a gas tank that supplies a gas containing an oxygen isotope as the oxidizing gas. The oxygen isotope is different from the specific oxygen compound contained in the oxygen-containing compound to be detected and / or quantified. 16 When a compound containing O is the object of detection and / or quantification, oxygen can be used as 17 O or 18 O gas is used as the oxidizing gas. The oxidizing gas may also contain inert gas such as helium and argon, and the ratio of oxygen to inert gas in the oxidizing gas is, for example, 1:99. The oxidizing gas supplied from the oxidizing gas supply unit 36 ​​is introduced into the interface unit 32.

[0037] The supplementary gas supply unit 38 is a gas tank independent of the oxidizing gas supply unit 36, and the oxidizing gas supply unit 36 ​​supplies an inert gas that does not affect the oxidative decomposition of the sample in the reaction tube 30. As the supplementary gas, helium gas and the like can be cited. The supplementary gas supplied from the supplementary gas supply unit 38 is introduced into the port 32 and the outlet adapter 34.

[0038] exist Figure 1 In the GC-Comb-MS mode shown, an inlet flow path 12 is connected to the downstream of the separation column 4, and the sample flowing out of the separation column 4 is introduced into the interface portion 32 of the oxidation decomposition device 6 through the inlet flow path 12. The sample introduced into the interface portion 32 is introduced into the reaction tube 30 together with the oxidation gas supplied from the oxidation gas supply portion 36 and the supplementary gas supplied from the supplementary gas supply portion 38, and is introduced into the mass spectrometer 8 after being subjected to oxidation decomposition in the reaction tube 30.

[0039] Here, use Figure 3 An example of a specific structure of the oxidation decomposition device 6 will be described.

[0040] A hollow cylindrical outer sleeve 40 is provided so as to surround the outer circumference of the reaction tube 30 of the oxidation decomposition device 6. The heating furnace 28 is in contact with the outer circumferential surface of the outer sleeve 40, and the outer sleeve 40 is heated by the heating furnace 28, thereby heating the reaction tube 30 passing through the inner side of the outer sleeve 40. The reaction tube 30 and the outer sleeve 40 are not in contact with each other, and there is a gap 64 between the outer circumferential surface of the reaction tube 30 and the inner circumferential surface of the outer sleeve 40. The outer sleeve 40 may be such that the main part housed in the heating furnace 28 is made of a heat-resistant material such as alumina, and at least the end portion held by the interface portion 32 is made of metal.

[0041] A space 42 is provided inside the interface part 32, and the space 42 connects the pipe (hereinafter also referred to as the pipe 12) forming the inlet flow path 12 and the reaction tube 30 fluid. Although not shown in the figure, a thread is provided on the outer peripheral surface of one end side (left side in the figure) of the outer sleeve 40. An opening is provided on the surface of the interface part 32 on the heating furnace 28 side, and a thread is provided inside the opening to be threadedly engaged with the thread on the outer peripheral surface of one end side of the outer sleeve 40. The outer sleeve 40 is held by the outer sleeve 40 by threading the thread on the outer peripheral surface of one end side with the thread on the inner side of the opening of the interface part 32. The retainer 40 and the seal 54 are provided in the opening of the interface part 32 in a manner sandwiched between the inside of the opening and the end of the outer sleeve 40. The retainer 48 is used to fix the position of one end of the reaction tube 30 in the interface part 32. The seal 54 is used to prevent the gas in the internal space 42 from leaking to the outside of the interface part 32 through the outside of the outer sleeve 40.

[0042] A hole is provided as an inlet 33 on the surface of the interface portion 32 on the side opposite to the side where the heating furnace 28 is located, and the pipe forming the inlet flow path 12 passes through the hole. The pipe 12 is inserted into the internal space 42 of the interface portion 32 from the inlet 33 while maintaining airtightness, and extends toward one end of the reaction tube 30. The interface portion 32 is provided with a supplementary gas introduction flow path 50 for introducing the supplementary gas supplied from the supplementary gas supply portion 38 into the internal space 42, and an oxidizing gas introduction flow path 52 for introducing the oxidizing gas supplied from the oxidizing gas supply portion 36 into the internal space 42. The supplementary gas introduced from the supplementary gas introduction flow path 50 is introduced into the gap between the inner surface of the interface portion 32 and the outer peripheral surface of the pipe 12, and the oxidizing gas introduced from the oxidizing gas introduction flow path 52 is introduced between the downstream end of the pipe 12 and one end of the reaction tube 30. The supplementary gas introduced from the supplementary gas introduction flow path 50 can prevent the sample introduced into the internal space 42 through the pipe 12 from flowing back toward the inlet 33 side.

[0043] The outlet adapter 34 has a structure in which the outer peripheral surface of the other end side (right side in the figure) of the outer sleeve 40 is airtightly held by O-rings 60 and 62, and the outer peripheral surface of the other end side (right side in the figure) of the reaction tube 30 is airtightly held by O-rings 58. A pipe (hereinafter also referred to as pipe 14) forming the outlet flow path 14 is inserted airtightly from the surface of the outlet adapter 34 on the side opposite to the side where the heating furnace 28 is located, and the other end of the reaction tube 30 and the pipe 14 are fluidically connected in an airtight manner inside the outlet adapter 34. The outlet adapter 34 is provided with a supplementary gas introduction flow path 56 for introducing the supplementary gas supplied from the supplementary gas supply unit 38 into the inside. The supplementary gas introduced from the supplementary gas introduction flow path 56 flows into the internal space 42 of the interface portion 32 through a gap 64 between the outer peripheral surface of the reaction tube 30 and the inner peripheral surface of the outer sleeve 40. This prevents the sample introduced into the internal space 42 of the interface portion 32 through the pipe 12 from flowing toward the outlet adapter 34 through the outside of the reaction tube 30 .

[0044] The sample introduced into the internal space 32 of the port 32 through the pipe 12 flows in the reaction tube 30 together with the oxidizing gas and the make-up gas, is oxidatively decomposed in the reaction tube 30 , and is introduced into the mass spectrometer 8 through the pipe 14 .

[0045] Figure 4 and Figure 5 This is the data, supplied as oxidizing gas in GC-Comb-MS mode 16 O and non-reactive gases ( 16 O gas: inert gas = 1:99) mixed gas, changing the temperature of the heating furnace 28 and taking as a sample to inject as 18 O oxygenated compounds 18-ethanol (CH3 18 OH) at each temperature, and the C in the sample after oxidative decomposition prepared based on the mass analysis data at each temperature 16 O2 (mass number = 44) and C 16 O 18 Data on the abundance ratio (44 / 46 ratio) of O (mass number = 46). Figure 4 It is the data measured by introducing helium as supplementary gas. Figure 5 The data are measured without introducing supplementary gas.

[0046] like Figure 5 As shown in the data, when the supplementary gas is not used, the 44 / 46 ratio increases greatly as the temperature of the heating furnace 28 increases. It is considered that if the temperature of the reaction tube 30 becomes high, the aluminum oxide used as the raw material of the reaction tube 30 will contain 16 O and C generated by oxidative decomposition 16O 18 O's 18 O exchange becomes active, C 16 O 18 O becomes C 16 O2. If the raw materials of the reaction tube 30 are 16 O and the oxygen isotope contained in the composition after oxidative decomposition will exchange, the ratio of the composition after oxidative decomposition will change, and the accuracy of detection and quantification of oxygen-containing compounds contained in the sample will decrease. Figure 5 The data clearly show that, although the inert gas is supplied as a carrier gas in addition to the inert gas contained in the oxidizing gas, the inert gas contained in the oxidizing gas and the inert gas used as a carrier gas cannot suppress the exchange of oxygen between the raw materials in the reaction tube 30 and the composition after oxidative decomposition.

[0047] On the other hand, Figure 4 As shown in the data, if the supplementary gas is introduced into the inner side of the reaction tube 30 together with the sample, when the heating furnace temperature exceeds 900°C, the 44 / 46 ratio increases slightly, but no significant change is found. In this way, if the inert gas is supplied to the inlet portion of the reaction tube 30 independently of the oxidizing gas and the carrier gas as the supplementary gas and the sample is oxidatively decomposed, the contact opportunity between the raw materials of the reaction tube 30 and the composition after oxidative decomposition is reduced, and the following effects can be obtained: the raw materials of the reaction tube 30 are suppressed from being 16 The exchange of O with the oxygen isotope contained in the composition after oxidative decomposition also suppresses the change in the ratio of the composition substances in the sample after oxidative decomposition.

[0048] Replay Figure 1 and Figure 2 Continue with the description of Analysis System 1.

[0049] The suction pump 18 is connected to the mass spectrometer 8 via a flow path 20 to reduce the pressure in the mass spectrometer 8. In addition, a pressure reducing flow path 22 is fluidically connected to the suction pump 18. A shutoff valve 24 and a flow path resistance adjuster 26 are provided on the pressure reducing flow path 22. Figure 2 As shown, in the GC-MS mode, the decompression channel 22 is fluidically connected to the outlet channel 14 , and the inside of the reaction tube 30 and the outlet channel 14 are decompressed by the suction pump 18 .

[0050] In the analysis system 1 , for example, the GC-MS mode is set before the target component is eluted from the separation column 4 , and when the target component is eluted from the separation column 4 , the GC-Comb-MS mode is switched to oxidatively decompose the target component, and mass analysis data of the composition after oxidative decomposition is acquired.

[0051] However, it is also considered that if the pressure in the reaction tube 30 in the GC-MS mode is greatly different from the pressure in the reaction tube 30 in the GC-Comb-MS mode, the pressure in the reaction tube 30 will fluctuate greatly when switching from the GC-MS mode to the GC-Comb-MS mode, and the time until the pressure in the reaction tube 30 stabilizes is long. If the target component is introduced into the reaction tube during this period, the efficiency of the oxidative decomposition of the target component decreases. In addition, it is also clear that if the pressure in the reaction tube 30 fluctuates greatly, the baseline of the output signal of the mass spectrometer 8 also fluctuates greatly, and the time required until the baseline stabilizes is also long. If the time required until the baseline of the output signal of the mass spectrometer 8 stabilizes is long, the target component will be introduced into the mass spectrometer 8 before the baseline stabilizes, and the detection accuracy of the target component may also decrease.

[0052] Therefore, in the analysis system 1, the difference between the pressure in the reaction tube 30 in the GC-MS mode and the pressure in the reaction tube 30 in the GC-Comb-MS mode is controlled within an allowable range set in consideration of the pressure fluctuation in the reaction tube 30 when switching from the GC-MS mode to the GC-Comb-MS mode (for example, it may be within 10% of the pressure in the reaction tube 30 in the GC-Comb-MS mode, but it is preferably as small as possible.). In the analysis system 1, by providing the flow path resistance regulator 26 in the decompression flow path 22, the decompression efficiency in the system from the oxidation decomposition device 6 to the suction pump 18 in the GC-MS mode is made close to the decompression efficiency in the system from the oxidation decomposition device 6 to the suction pump 18 in the GC-Comb-MS mode, thereby controlling the difference between the pressure in the reaction tube 30 in the GC-MS mode and the pressure in the reaction tube 30 in the GC-Comb-MS mode within the allowable range. The flow path resistance regulator 26 may be a resistance tube having a fixed flow path resistance value, or may be a needle valve, a proportional solenoid valve, or the like whose flow path resistance can be variably adjusted.

[0053] Figure 6 The data are verification results showing how the length of the resistance tube as the flow path resistance adjuster 26 affects the change in the outlet pressure of the reaction tube 30 when switching from the GC-MS mode to the GC-Comb-MS mode. Figure 7 The data are verification results showing how the length of the resistance tube as the flow path resistance adjuster 26 affects the change in the baseline of the output signal of the mass spectrometer 8 when switching from the GC-MS mode to the GC-Comb-MS mode.

[0054] according to Figure 6 and Figure 7According to the data, when no resistance tube is provided on the decompression flow path 22, the outlet pressure of the reaction tube 30 in the GC-MS mode is extremely low. When switching to the GC-Comb-MS mode, the outlet pressure of the reaction tube 30 changes greatly, and the baseline of the output signal (detector signal) of the mass spectrometer 8 also changes greatly, and the time required for the baseline to stabilize is long. Moreover, if a resistance tube is provided on the decompression flow path 22 to increase the flow path resistance of the decompression flow path 22, the pressure in the reaction tube 30 in the GC-MS mode also becomes higher. When a resistance tube with a length of 30 mm is provided, the change in the outlet pressure of the reaction tube 30 is the smallest, and the change in the baseline of the detector signal is also the smallest. On the other hand, if the length of the resistance tube is set to 50 mm or more, the pressure in the reaction tube 30 in the GC-MS mode is higher than that in the GC-Comb-MS mode, and the pressure change when switching to the GC-Comb-MS mode is also large.

[0055] According to the above verification results, it can be seen that in the GC-MS mode, by appropriately adjusting the flow resistance of the reduced pressure flow path 22 assembled between the oxidative decomposition device 6 and the suction pump 18 using the flow path resistance adjuster 26, the pressure fluctuation in the reaction tube 30 when switching from the GC-MS mode to the GC-Comb-MS mode can be reduced.

[0056] The above-described embodiment is merely an example of an embodiment of the analysis system of the present invention. An embodiment of the analysis system of the present invention is as follows.

[0057] One embodiment of the analysis system of the present invention is an analysis system comprising: an oxidation decomposition device having an inlet and an outlet, wherein a sample introduced from the inlet is oxidatively decomposed and then discharged from the outlet; and a detector for detecting an oxidation reaction product obtained by oxidation decomposition by the oxidation decomposition device, wherein the analysis system is used to detect and / or quantify a compound containing a specific oxygen component in the sample, wherein:

[0058] The oxidative decomposition device comprises:

[0059] A reaction tube having one end and another end, wherein the one end is arranged at the inlet side and the other end is arranged at the outlet side, and the reaction tube is used for performing oxidative decomposition of the sample inside;

[0060] a heating furnace, which accommodates the reaction tube inside and is used to heat the reaction tube;

[0061] an oxidizing gas supply unit that supplies an oxidizing gas for oxidizing the sample, the oxidizing gas containing an oxygen component having an isotope different from the specific oxygen component;

[0062] a supplementary gas supply unit that supplies a supplementary gas that is an inert gas that does not affect oxidative decomposition of the sample; and

[0063] The interface portion has a structure for introducing the oxidizing gas supplied from the oxidizing gas supply portion and the supplementary gas supplied from the supplementary gas supply portion into the inner side of the reaction tube together with the sample introduced from the inlet.

[0064] In the aspect [1] of the above-mentioned embodiment, the oxidizing gas supplied from the oxidizing gas supply unit and the make-up gas supplied from the make-up gas supply unit are supplied to the interface unit through mutually independent flow paths.

[0065] In the above-mentioned state [1], the interface portion includes an oxidation gas introduction path for allowing the oxidation gas and the supplementary gas to merge into the internal space of the sample introduced from the inlet, an oxidation gas introduction path for introducing the oxidation gas supplied from the oxidation gas supply portion into the internal space, and a supplementary gas introduction path for introducing the supplementary gas supplied from the supplementary gas supply portion into the internal space, and the interface portion has a structure for introducing the sample, the oxidation gas and the supplementary gas merged in the internal space into the reaction tube from the one end of the reaction tube.

[0066] In the aspect [2] of the above embodiment, at least the inner surface of the reaction tube is formed of a heat-resistant material, and the heat-resistant material is made of an oxide. This aspect [2] can be combined with the above aspect [1].

[0067] In the above aspect [2], the heat-resistant material may be alumina.

[0068] In the above-mentioned embodiment [3],

[0069] include:

[0070] A sample supply device (2, 4) having a structure for supplying the sample downstream using a carrier gas;

[0071] a mass spectrometer as the detector;

[0072] A switching mechanism for switching flow path connection; and

[0073] a suction pump, which is used to reduce the pressure in the reaction tube of the oxidative decomposition device,

[0074] The switching mechanism is configured to establish one of a first state and a second state, wherein in the first state, the oxidation decomposition device is not present between the sample supply device and the mass spectrometer, and the mass spectrometer is connected to a downstream fluid of the sample supply device; and in the second state, the inlet of the oxidation decomposition device is connected to a downstream fluid of the sample supply device, and the mass spectrometer is connected to a downstream fluid of the outlet of the oxidation decomposition device.

[0075] The suction pump is configured to be fluidically connected to the downstream of the oxidative decomposition device in the first state, and the difference between the pressure in the reaction tube in the first state and the pressure in the reaction tube in the second state is controlled within an allowable range set in consideration of the magnitude of the pressure change in the reaction tube when the switching mechanism switches from the first state to the second state. This aspect [3] can be combined with the above-mentioned aspect [1] and / or aspect [2].

[0076] In the above-mentioned state [3], it can also be configured that, in the first state, the suction pump is fluidically connected to the mass spectrometer while being fluidically connected to the downstream of the oxidation decomposition device, and in the second state, the suction pump is fluidically connected to the mass spectrometer. In this case, it can also be configured that in the first state, the flow path resistance of the flow path assembled between the oxidation decomposition device and the suction pump is set so that the decompression efficiency in the system from the oxidation decomposition device to the suction pump in the first state is substantially the same as the decompression efficiency in the system from the oxidation decomposition device to the suction pump in the second state.

[0077] In the above aspect [3], the allowable range may be a range within 10% of the pressure in the reaction tube in the second state.

[0078] In addition, in the above aspect [3], the sample supply device may be a gas chromatograph.

[0079] Description of Reference Numerals

[0080] 1. Analysis system; 2. Sample vaporization chamber; 4. Separation column; 6. Oxidation decomposition device; 10. Switching valve; 12, 14, 16, 20, 22. Flow path; 18. Suction pump; 24. Shut-off valve; 26. Flow path resistance adjuster; 28. Heating furnace; 30. Reaction tube; 32. Interface; 33. Inlet; 34. Outlet adapter; 35. Outlet; 36. Oxidation gas supply unit; 38. Supplementary gas supply unit; 40. Outer sleeve; 42. Internal space; 48. Retaining part; 50, 56. Supplementary gas introduction flow path; 52. Oxidation gas introduction flow path; 54. Seal; 58, 60, 62. O-ring.

Claims

1. An analysis system comprising: an oxidative decomposition device having an inlet and an outlet, wherein the sample introduced from the inlet is oxidatively decomposed and then flows out from the outlet; and a detector for detecting the oxidation reaction product obtained by the oxidation decomposition device, the analysis system for detecting and / or quantifying the compound containing a specific oxygen component in the sample, wherein: The oxidative decomposition device comprises: A reaction tube having one end and another end, wherein the one end is arranged at the inlet side and the other end is arranged at the outlet side, and the reaction tube is used for performing oxidative decomposition of the sample inside; a heating furnace, which accommodates the reaction tube inside and is used to heat the reaction tube; an oxidizing gas supply unit that supplies an oxidizing gas for oxidizing the sample, the oxidizing gas containing an oxygen component having an isotope different from the specific oxygen component; a supplementary gas supply unit that supplies a supplementary gas that is an inert gas that does not affect oxidative decomposition of the sample; and The interface portion has a structure for introducing the oxidizing gas supplied from the oxidizing gas supply portion and the supplementary gas supplied from the supplementary gas supply portion into the inner side of the reaction tube together with the sample introduced from the inlet.

2. The analysis system according to claim 1, wherein: The oxidizing gas supplied from the oxidizing gas supply unit and the make-up gas supplied from the make-up gas supply unit are supplied to the interface unit through mutually independent flow paths.

3. The analysis system according to claim 2, wherein: The interface portion includes an oxidation gas introduction path for allowing the oxidation gas and the supplementary gas to merge into the internal space of the sample introduced from the inlet, an oxidation gas introduction path for introducing the oxidation gas supplied from the oxidation gas supply portion into the internal space, and a supplementary gas introduction path for introducing the supplementary gas supplied from the supplementary gas supply portion into the internal space. The interface portion has a structure for introducing the sample, the oxidation gas and the supplementary gas merged in the internal space into the reaction tube from one end of the reaction tube.

4. The analysis system according to claim 1, wherein: At least an inner surface of the reaction tube is formed of a heat-resistant material made of an oxide.

5. The analysis system according to claim 4, wherein: The heat-resistant material is alumina.

6. The analysis system according to claim 1, wherein: The analysis system includes: A sample supply device having a structure for supplying a sample downstream using a carrier gas; a mass spectrometer as the detector; A switching mechanism for switching flow path connection; and a suction pump, which is used to reduce the pressure in the reaction tube of the oxidative decomposition device, The switching mechanism is configured to establish one of a first state and a second state, wherein in the first state, the oxidation decomposition device is not present between the sample supply device and the mass spectrometer, and the mass spectrometer is connected to a downstream fluid of the sample supply device; and in the second state, the inlet of the oxidation decomposition device is connected to a downstream fluid of the sample supply device, and the mass spectrometer is connected to a downstream fluid of the outlet of the oxidation decomposition device. The suction pump is configured such that, in the first state, the fluid is connected to the downstream of the oxidative decomposition device, and the difference between the pressure in the reaction tube in the first state and the pressure in the reaction tube in the second state is controlled within an allowable range set in consideration of the magnitude of the pressure change in the reaction tube when switching from the first state to the second state using the switching mechanism.

7. The analysis system according to claim 6, wherein: The suction pump is configured such that, in the first state, the suction pump is fluidically connected to the downstream of the oxidative decomposition device and is fluidically connected to the mass spectrometer, and in the second state, the suction pump is fluidically connected to the mass spectrometer. In the first state, the flow resistance of the flow path assembled between the oxidation decomposition device and the suction pump is set so that the decompression efficiency in the system from the oxidation decomposition device to the suction pump in the first state is substantially the same as the decompression efficiency in the system from the oxidation decomposition device to the suction pump in the second state.

8. The analysis system according to claim 6, wherein: The allowable range is a range within 10% of the pressure in the reaction tube in the second state.

9. The analysis system according to claim 6, wherein: The sample supply device is a gas chromatograph.

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