Analysis device and analysis method for electronic-grade bromomethane

Abstract

The invention relates to the technical field of gas analysis devices and analysis methods thereof, in particular to an electronic-grade bromomethane analysis device which comprises a first switching valve, a second switching valve, a third switching valve, a fourth switching valve, a fifth switching valve and a sixth switching valve, ten connectors are arranged on each of the first switching valve, the second switching valve and the fourth switching valve, the third switching valve, the fifth switching valve and the sixth switching valve are each provided with six connectors, and the sixth switching valve is connected with a second detector. Therefore, the electronic-grade bromomethane analysis device can solve the technical problems that all components to be detected cannot be quickly separated, the impurity concentration change cannot be detected, an accurate value cannot be given in a very short time, the detection limit is low and the like in the prior art.

Description

Technical Field

[0001] The present application relates to the technical field of gas analysis devices and analysis methods thereof, and more specifically, to an analysis device and analysis method for electronic grade methyl bromide. Background Art

[0002] Electronic grade methyl bromide is an organic compound with the chemical formula CH3Br. It is an insoluble, colorless gas. Methyl bromide is widely used in organic synthesis, drug manufacturing, semiconductors, optoelectronics, liquid crystal display and other electronic industries. In the manufacture of electronic components, methyl bromide can be used as a cleaning agent to clean circuit boards and semiconductor devices.

[0003] At present, there are no reports on the analysis method of electronic-grade methyl bromide in domestic literature. In the trace analysis of electronic-grade methyl bromide, the most important thing is to be able to quickly separate all components to be tested, quickly detect changes in impurity concentrations, give accurate values ​​in a very short time, and have low detection limits. Summary of the invention

[0004] Based on the above problems, the present application proposes an analysis device and analysis method for electronic grade methyl bromide, which are used to solve the technical problems that the existing technology cannot quickly separate all components to be tested, detect changes in impurity concentrations, give accurate values ​​in a very short time, and has low detection limits.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] An analysis device for electronic-grade methyl bromide comprises a first switching valve, a second switching valve, a third switching valve, a fourth switching valve, a fifth switching valve and a sixth switching valve, wherein the first switching valve, the second switching valve and the fourth switching valve are each provided with ten interfaces, and the third switching valve, the fifth switching valve and the sixth switching valve are each provided with six interfaces, the first switching valve is provided with a first quantitative tube and a first pre-separation column; the second switching valve is provided with a second quantitative tube and a second pre-separation column; the third switching valve is provided with a first detector; the fourth switching valve is provided with a third quantitative tube, a fourth quantitative tube and a pressure sensor; a first analysis column is provided between the first switching valve and the third switching valve; a second analysis column is provided between the second switching valve and the third switching valve; a third pre-separation column is provided between the fourth switching valve and the fifth switching valve; a third analysis column is provided between the fifth switching valve and the sixth switching valve; a fourth analysis column is provided between the fourth switching valve and the sixth switching valve, and the sixth switching valve is connected with a second detector.

[0007] In a specific feasible implementation scheme, a two-stage pressure-stabilizing valve is provided on the carrier gas main pipe, the first carrier gas branch pipe is connected to the No. 1 interface of the first switching valve, the second carrier gas branch pipe is connected to the No. 8 interface of the first switching valve, the third carrier gas branch pipe is connected to the No. 1 interface of the second switching valve, the fourth carrier gas branch pipe is connected to the No. 8 interface of the second switching valve, the fifth carrier gas branch pipe is connected to the No. 9 interface of the fourth switching valve, the sixth carrier gas branch pipe is connected to the No. 4 interface of the fourth switching valve, and the seventh carrier gas branch pipe is connected to the No. 6 interface of the fifth switching valve, and the first carrier gas branch pipe, the second carrier gas branch pipe, the third carrier gas branch pipe, the fourth carrier gas branch pipe, the fifth carrier gas branch pipe, the sixth carrier gas branch pipe and the seventh carrier gas branch pipe are respectively provided with a carrier gas flow-stabilizing valve to ensure a stable flow rate.

[0008] In a specific feasible implementation scheme, a first quantitative cup is connected between interface No. 2 and interface No. 5 of the first switching valve, a second quantitative cup is connected between interface No. 2 and interface No. 5 of the second switching valve, a fourth quantitative cup is connected between interface No. 3 and interface No. 6 of the fourth switching valve, and a third quantitative cup is connected between interface No. 10 and interface No. 7 of the fourth switching valve.

[0009] In a specific implementation scheme, the first pre-separation column is a CST packed column with a length of 0.8 m, an inner diameter of 1 / 8 ", and a 60-100 mesh; the second pre-separation column is a Hayesep R packed column with a length of 2 m, an inner diameter of 1 / 8 ", and a 60-80 mesh; the third pre-separation column is a DB-1 capillary column with a length of 30 m*0.53 mm and a 60-100 mesh; the first analytical column is a 13X packed column with a length of 2 m, an inner diameter of 1 / 8 ", and a 60-80 mesh; the second analytical column is a Hayesep R packed column with a length of 6 m, an inner diameter of 1 / 8 ", and a 60-80 mesh; the third analytical column is a DB-1 capillary column with a length of 30 m*0.53 mm and a 60-100 mesh; the fourth analytical column is a DB-WAX capillary column with a length of 50 m*0.53 mm and a 60-100 mesh, and all analytical columns and separation columns use stainless steel pipes with passivated inner walls.

[0010] In a specific feasible implementation scheme, the inner walls of all stainless steel connecting pipelines are passivated pipelines specially treated with electronic grade methyl bromide to prevent adsorption.

[0011] In a specific feasible implementation scheme, a pressure sensor is connected to the No. 2 interface of the fourth switching valve, a sample outlet pipe is provided on the pressure sensor, and the pressure sensor has a range of -0.1 to 1.1 MPa.

[0012] In a specific implementation scheme, a sample inlet tube is provided on the third interface of the first switching valve.

[0013] In a specific implementation scheme, the first detector and the second detector use VICI's helium ionization detector, the detection limit can be increased to 10PPb, and a 6-valve 7-column process is used to achieve full separation of all components in one injection.

[0014] In a specific implementation scheme, the fifth switching valve and the sixth switching valve are both connected to a venting pipeline.

[0015] In a specific implementation scheme, the following steps are included:

[0016] S1: Before starting the analysis, each connecting pipeline is purged and replaced by helium purging and vacuuming. After the replacement, the sample to be tested is introduced into the purging injection pipeline. The sample gas to be tested passes through the sample inlet pipe to the first switching valve, and passes through the third interface, the second interface, the fifth interface, and the fourth interface of the first switching valve in turn. After the fourth interface of the first switching valve is connected to the third interface of the second switching valve through a stainless steel pipe, it passes through the second interface, the fifth interface, and the fourth interface of the second switching valve in turn. After the fourth interface is connected to the first interface of the fourth switching valve through a stainless steel pipe, it passes through the first interface, the tenth interface, the seventh interface, the sixth interface, the third interface, and the second interface of the second switching valve in turn. Then, the second interface is connected to the pressure sensor, so that the sample fills four 0.5mL quantitative loops;

[0017] S2: During injection, the pressure reading will be transmitted to the chromatographic workstation, and the pressure of the valve at the front end of the injection port will be adjusted to ensure that the injection volume is consistent each time.

[0018] S3: After the analysis starts, the first switching valve, the second switching valve and the fourth switching valve are switched simultaneously, so that the first switching valve, the second switching valve and the fourth switching valve are changed from the reset state to the switching state.

[0019] S4: The carrier gas of the first carrier gas branch pipe sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface, and No. 6 interface of the first switching valve to substitute the sample in the first quantitative loop into the first pre-separation column for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide, and methane in the sample first flow out of the first pre-separation column to the first analytical column. When methane flows into the first analytical column, the first switching valve switches to the reset state; the hydrogen, oxygen, argon, nitrogen, carbon monoxide, and methane in the sample are separated by the first analytical column, and the H2, O2, Ar, N2, CH4, and CO in the sample sequentially flow into the first detector through the No. 3 interface and No. 2 interface of the third switching valve;

[0020] S5: The carrier gas of the third carrier gas branch pipe sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface and No. 6 interface of the second switching valve to substitute the sample in the second quantitative loop into the second pre-separation column for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide, methane and carbon dioxide in the sample first flow out of the second pre-separation column to the second analytical column. When the carbon dioxide flows into the second analytical column, the second switching valve is switched to the reset state. After separation by the second analytical column, the hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane in the sample are discharged into the vent line through the No. 1 interface, No. 6 interface, No. 5 interface and No. 4 interface of the third switching valve. After the methane is discharged, the third switching valve is switched to the switching state, and the carbon dioxide in the sample sequentially flows into the first detector through the No. 1 interface and No. 2 interface of the third switching valve.

[0021] S6: The carrier gas of the fifth carrier gas branch pipe passes through the No. 9 interface, No. 10 interface, No. 7 interface and No. 8 interface of the fourth switching valve in turn to substitute the sample in the third quantitative loop into the third pre-separation column for separation. The chloromethane, bromomethane, dichloromethane, bromine gas, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane and bromoform in the sample flow out of the third pre-separation column in turn and flow into the third analytical column for separation. The chloromethane in the sample flows into the third analytical column through the No. 4 interface and No. 5 interface of the pneumatic six-way valve for separation. After the chloromethane flows into the third analytical column, the fifth switching valve is switched to the switching state. The carrier gas of the seventh carrier gas branch pipe flows into the third analytical column through the No. 6 interface and No. 5 interface of the fifth switching valve in turn, and then flows into the second detector through the No. 1 interface and No. 6 interface of the sixth switching valve. Most of the bromomethane in the sample is discharged into the venting pipeline through the No. 4 interface and No. 3 interface of the fifth switching valve. When most of the methyl bromide in the sample is vented, the fifth switching valve is switched to the reset state, and the dichloromethane, bromine gas, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane, and bromoform in the sample flow into the third analytical column through the No. 4 and No. 5 interfaces of the fifth switching valve, and flow into the second detector through the No. 1 and No. 6 interfaces of the sixth switching valve;

[0022] S7: The carrier gas of the sixth carrier gas branch pipe sequentially passes through the No. 4 interface, No. 3 interface, No. 6 interface, and No. 5 interface of the fourth switching valve to substitute the sample in the fourth quantitative loop into the fourth analytical column for separation. The methyl bromide, hydrogen bromide, and methanol in the sample sequentially flow into the fourth analytical column for separation. After the methyl bromide in the sample flows into the fourth analytical column, it is discharged into the venting pipeline through the No. 5 interface, No. 4 interface, No. 2 interface, and No. 3 interface of the sixth switching valve. When most of the methyl bromide in the sample is vented, the sixth switching valve is switched to the switching state, and the hydrogen dibromide and methanol in the sample flow into the second detector through the No. 5 interface and No. 6 interface of the sixth switching valve;

[0023] S8: Through the integration processing of the chromatography workstation, one injection can generate a spectrum showing the detection results of two detectors.

[0024] Positive effects of the present invention:

[0025] 1. The present invention uses two highly sensitive helium ionization detectors, six switching valves, four quantitative loops, and seven chromatographic columns to form an analysis system. The required impurities can be selectively placed in the two helium ionization detectors by valve switching, avoiding interference from the main component, achieving complete separation of the target peak, and increasing quantitative accuracy. It meets the requirements for the detection of trace impurities in electronic grade methyl bromide.

[0026] 2. The present invention uses a pressure stabilizing valve and a flow stabilizing valve in combination, and adds a pipeline with a thinner inner diameter to make the carrier gas flow more stable, reduce interference factors in the gas path, and further ensure the accuracy of the analysis. All impurities to be measured are completely separated to meet the analysis requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 It is a structural schematic diagram of all valves in the present invention in a reset state.

[0029] Figure 2 It is a structural schematic diagram of all valves in the present invention in a switching state.

[0030] Description of Reference Numerals

[0031] 101, the first switching valve; 201, the second switching valve; 301, the third switching valve; 401, the fourth switching valve; 501, the fifth switching valve; 601, the sixth switching valve; 102, the first carrier gas branch; 103, the first quantitative cup; 104, the second carrier gas branch; 105, the first pre-separation column; 202, the third carrier gas branch; 203, the second quantitative cup; 204, the fourth carrier gas branch; 205, the second pre-separation column; 302, the first analytical column; 303, the second analytical column; 304, the first detector; 402, the fifth carrier gas branch; 403, the third quantitative cup; 404, the fourth quantitative cup; 405, the sixth carrier gas branch; 406, the pressure sensor; 502, the seventh carrier gas branch; 503, the third pre-separation column; 602, the fourth analytical column; 603, the third analytical column; 604, the second detector. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] Example 1

[0034] like Figure 1 and 2 As shown, an electronic grade methyl bromide analysis device includes a first switching valve 101, a second switching valve 201, a third switching valve 301, a fourth switching valve 401, a fifth switching valve 501 and a sixth switching valve 601. A first quantitative cup 103 is connected between the second interface and the fifth interface of the first switching valve 101, a second quantitative cup 203 is connected between the second interface and the fifth interface of the second switching valve 201, a fourth quantitative cup 404 is connected between the third interface and the sixth interface of the fourth switching valve 401, and a third quantitative cup 403 is connected between the tenth interface and the seventh interface of the fourth switching valve 401. Venting pipelines are connected to the fifth switching valve 501 and the sixth switching valve 601.

[0035] The first switching valve 101, the second switching valve 201 and the fourth switching valve 401 are all provided with ten interfaces, the third switching valve 301, the fifth switching valve 501 and the sixth switching valve 601 are all provided with six interfaces, the first switching valve 101 is provided with a first quantitative tube and a first pre-separation column 105; the second switching valve 201 is provided with a second quantitative tube and a second pre-separation column 205; the third switching valve 301 is provided with a first detector 304; the fourth switching valve 401 is provided with a third quantitative tube, a fourth quantitative tube and a pressure sensor 406; the pressure sensor 406 is connected to the No. 2 interface of the fourth switching valve 401, and the pressure sensor 406 is provided with a sample outlet tube, and the range of the pressure sensor 406 is -0.1 to 1.1Mpa. The flexible configuration of the switching valve allows the carrier gas and the sample to be efficiently switched between multiple analytical columns and separation columns, thereby achieving effective separation of different components.

[0036] A first analytical column 302 is arranged between the first switching valve 101 and the third switching valve 301; a second analytical column 303 is arranged between the second switching valve 201 and the third switching valve 301; a third pre-separation column 503 is arranged between the fourth switching valve 401 and the fifth switching valve 501; a third analytical column 603 is arranged between the fifth switching valve 501 and the sixth switching valve 601; a fourth analytical column 602 is arranged between the fourth switching valve 401 and the sixth switching valve 601, and a second detector 604 is connected to the sixth switching valve 601. The first detector 304 and the second detector 604 use VICI's helium ionization detector (PDHID), and the detection limit can be increased to 10PPb. A 6-valve 7-column process is used to achieve full separation of all components in one injection. Six switching valves are designed for the device, of which the first, second and fourth switching valves 401 have ten interfaces, and the third, fifth and sixth switching valves 601 have six interfaces. The flexible configuration of these switching valves enables the carrier gas and the sample to be efficiently switched and separated between multiple analytical columns and separation columns.

[0037] Each switching valve is connected to a specific analytical column or separation column, as well as a quantitative cup and a venting line, ensuring the smoothness and accuracy of the analysis process.

[0038] A double-stage pressure-stabilizing valve is provided on the carrier gas main pipe, the first carrier gas branch pipe 102 is connected to the No. 1 interface of the first switching valve 101 , and a sample inlet pipe is provided on the No. 3 interface of the first switching valve 101 .

[0039] The second carrier gas branch pipe 104 is connected to the No. 8 interface of the first switching valve 101, the third carrier gas branch pipe 202 is connected to the No. 1 interface of the second switching valve 201, the fourth carrier gas branch pipe 204 is connected to the No. 8 interface of the second switching valve 201, the fifth carrier gas branch pipe 402 is connected to the No. 9 interface of the fourth switching valve 401, the sixth carrier gas branch pipe 405 is connected to the No. 4 interface of the fourth switching valve 401, and the seventh carrier gas branch pipe 502 is connected to the No. 6 interface of the fifth switching valve 501. The first carrier gas branch pipe 102, the second carrier gas branch pipe 104, the third carrier gas branch pipe 202, the fourth carrier gas branch pipe 204, the fifth carrier gas branch pipe 402, the sixth carrier gas branch pipe 405 and the seventh carrier gas branch pipe 502 are respectively provided with a carrier gas steady flow valve to ensure a stable flow rate.

[0040] The first pre-separation column 105 is a CST column with a length of 0.8 m, an inner diameter of 1 / 8″, and a 60-100 mesh packing. The second pre-separation column 205 is a Hayesep R column with a length of 2 m, an inner diameter of 1 / 8″, and a 60-80 mesh packing. The third pre-separation column 503 is a DB-1 capillary column with a length of 30 m*0.53 mm and a 60-100 mesh packing. The first analytical column 302 is a 13X column with a length of 2 m, an inner diameter of 1 / 8″, and a 60-80 mesh packing. The second analytical column 303 is a Hayesep R column with a length of 6 m, an inner diameter of 1 / 8″, and a 60-80 mesh packing. R filling column; the third analytical column 603 is a DB-1 capillary column with a length of 30m*0.53mm and a 60-100 mesh; the fourth analytical column 602 is a DB-WAX capillary column with a length of 50m*0.53mm and a 60-100 mesh. All analytical columns and separation columns use stainless steel pipes with passivated inner walls. The connection methods used in this device all use stainless steel pipes. The inner walls of all stainless steel connecting pipes are passivated pipes specially treated with electronic-grade methyl bromide to prevent adsorption. The device uses analytical columns and separation columns of various lengths, inner diameters and fillings. These columns have been carefully selected and optimized to ensure the effective separation and analysis of methyl bromide and its related components.

[0041] All analytical and separation columns use stainless steel tubing with passivated inner walls to reduce the possibility of adsorption and contamination.

[0042] Example 2

[0043] The difference between this embodiment and the above embodiment is that the analysis method is described in more detail, including the following steps:

[0044] S1: Before starting the analysis, each connecting pipeline is purged and replaced by helium purging and vacuuming. After the replacement, the sample to be tested is introduced into the purging injection pipeline. The sample gas to be tested passes through the sample inlet pipe to the first switching valve 101, and passes through the third interface, the second interface, the fifth interface, and the fourth interface of the first switching valve 101 in turn. After the fourth interface of the first switching valve 101 is connected to the third interface of the second switching valve 201 through a stainless steel pipe, it passes through the second interface, the fifth interface, and the fourth interface of the second switching valve 201 in turn. After the fourth interface is connected to the first interface of the fourth switching valve 401 through a stainless steel pipe, it passes through the first interface, the tenth interface, the seventh interface, the sixth interface, the third interface, and the second interface of the second switching valve 201 in turn, and then the second interface is connected to the pressure sensor 406, so that the sample fills four 0.5mL quantitative loops;

[0045] S2: During injection, the pressure reading will be transmitted to the chromatographic workstation, and the pressure of the valve at the front end of the injection port will be adjusted to ensure that the injection volume is consistent each time.

[0046] S3: After the analysis starts, the first switching valve 101, the second switching valve 201 and the fourth switching valve 401 are switched simultaneously, so that the first switching valve 101, the second switching valve 201 and the fourth switching valve 401 are changed from the reset state to the switching state.

[0047] S4: The carrier gas of the first carrier gas branch pipe 102 sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface, and No. 6 interface of the first switching valve 101 to substitute the sample in the first quantitative loop into the first pre-separation column 105 for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide, and methane in the sample first flow out of the first pre-separation column 105 to the first analytical column 302. When methane flows into the first analytical column 302, the first switching valve 101 switches to the reset state; the hydrogen, oxygen, argon, nitrogen, carbon monoxide, and methane in the sample are separated by the first analytical column 302, and the H2, O2, Ar, N2, CH4, and CO in the sample sequentially flow into the first detector 304 through the No. 3 interface and No. 2 interface of the third switching valve 301;

[0048] S5: The carrier gas of the third carrier gas branch pipe 202 sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface and No. 6 interface of the second switching valve 201 to substitute the sample in the second quantitative loop into the second pre-separation column 205 for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide, methane and carbon dioxide in the sample first flow out of the second pre-separation column 205 to the second analysis column 303. When the carbon dioxide flows into the second analysis column 303, the second switching valve 201 switches to the reset state and is separated by the second analysis column 303. The hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane in the sample are discharged into the venting pipeline through the No. 1 interface, No. 6 interface, No. 5 interface and No. 4 interface of the third switching valve 301. After the methane is discharged, the third switching valve 301 is switched to the switching state, and the carbon dioxide in the sample sequentially flows into the first detector 304 through the No. 1 interface and No. 2 interface of the third switching valve 301.

[0049] S6: The carrier gas of the fifth carrier gas branch pipe 402 sequentially passes through the No. 9 interface, No. 10 interface, No. 7 interface, and No. 8 interface of the fourth switching valve 401 to substitute the sample in the third quantitative loop into the third pre-separation column 503 for separation. The chloromethane, bromomethane, dichloromethane, bromine gas, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane, and bromoform in the sample sequentially flow out of the third pre-separation column 503 and flow into the third analytical column 603 for separation. The chloromethane in the sample passes through the pneumatic six-way valve. Interface No. 4 and interface No. 5 flow into the third analytical column 603 for separation. After chloromethane flows into the third analytical column 603, the fifth switching valve 501 is switched to the switching state, and the carrier gas of the seventh carrier gas branch pipe 502 flows into the third analytical column 603 through the interface No. 6 and interface No. 5 of the fifth switching valve 501 in sequence, and then flows into the second detector 604 through the interface No. 1 and interface No. 6 of the sixth switching valve 601; most of the bromomethane in the sample is discharged into the venting pipeline through the interface No. 4 and interface No. 3 of the fifth switching valve 501. When most of the bromomethane in the sample is vented, the fifth switching valve 501 is switched to the reset state, and the dichloromethane, bromine gas, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane, and bromoform in the sample flow into the third analytical column 603 through the interface No. 4 and interface No. 5 of the fifth switching valve 501, and flow into the second detector 604 through the interface No. 1 and interface No. 6 of the sixth switching valve 601;

[0050] S7: The carrier gas of the sixth carrier gas branch pipe 405 sequentially passes through the No. 4 interface, No. 3 interface, No. 6 interface, and No. 5 interface of the fourth switching valve 401 to substitute the sample in the fourth quantitative loop into the fourth analytical column 602 for separation. The methyl bromide, hydrogen bromide, and methanol in the sample sequentially flow into the fourth analytical column 602 for separation. After the methyl bromide in the sample flows into the fourth analytical column 602, it is discharged into the venting pipeline through the No. 5 interface, No. 4 interface, No. 2 interface, and No. 3 interface of the sixth switching valve 601. When most of the methyl bromide in the sample is vented, the sixth switching valve 601 is switched to the switching state, and the hydrogen dibromide and methanol in the sample flow into the second detector 604 through the No. 5 interface and No. 6 interface of the sixth switching valve 601;

[0051] S8: Through the integration processing of the chromatography workstation, one injection can generate a spectrum showing the detection results of two detectors.

[0052] By combining the separation characteristics of the pre-separation column and the analytical column, and coordinating with valve cutting technology, tasks that originally required multiple analyses can be fully detected in one injection, which is very simple and quick in practical value.

[0053] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0054] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An analysis device for electronic grade methyl bromide, characterized in that: The invention comprises a first switching valve (101), a second switching valve (201), a third switching valve (301), a fourth switching valve (401), a fifth switching valve (501) and a sixth switching valve (601). The first switching valve (101), the second switching valve (201) and the fourth switching valve (401) are each provided with ten interfaces, the third switching valve (301), the fifth switching valve (501) and the sixth switching valve (601) are each provided with six interfaces, the first switching valve (101) is provided with a first quantitative tube and a first pre-separation column (105); the second switching valve (201) is provided with a second quantitative tube and a second pre-separation column (205); the third switching valve (301) is provided with a first detector (304); the fourth switching valve (401) is provided with a third quantitative tube, a fourth quantitative tube and a pressure sensor (406); a first analytical column (302) is arranged between the first switching valve (101) and the third switching valve (301); a second analytical column (303) is arranged between the second switching valve (201) and the third switching valve (301); a third pre-separation column (503) is arranged between the fourth switching valve (401) and the fifth switching valve (501); a third analytical column (603) is arranged between the fifth switching valve (501) and the sixth switching valve (601); a fourth analytical column (602) is arranged between the fourth switching valve (401) and the sixth switching valve (601), and a second detector (604) is connected to the sixth switching valve (601).

2. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: A two-stage pressure-stabilizing valve is provided on the carrier gas main pipe, the first carrier gas branch pipe (102) is connected to the No. 1 interface of the first switching valve (101), the second carrier gas branch pipe (104) is connected to the No. 8 interface of the first switching valve (101), the third carrier gas branch pipe (202) is connected to the No. 1 interface of the second switching valve (201), the fourth carrier gas branch pipe (204) is connected to the No. 8 interface of the second switching valve (201), and the fifth carrier gas branch pipe (402) is connected to the No. 9 interface of the fourth switching valve (401). , the sixth carrier gas branch pipe (405) is connected to the fourth interface of the fourth switching valve (401), the seventh carrier gas branch pipe (502) is connected to the sixth interface of the fifth switching valve (501), and the first carrier gas branch pipe (102), the second carrier gas branch pipe (104), the third carrier gas branch pipe (202), the fourth carrier gas branch pipe (204), the fifth carrier gas branch pipe (402), the sixth carrier gas branch pipe (405) and the seventh carrier gas branch pipe (502) are respectively provided with a carrier gas steady flow valve to ensure a stable flow rate.

3. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: A first quantitative cup (103) is connected between the No. 2 interface and the No. 5 interface of the first switching valve (101), a second quantitative cup (203) is connected between the No. 2 interface and the No. 5 interface of the second switching valve (201), a fourth quantitative cup (404) is connected between the No. 3 interface and the No. 6 interface of the fourth switching valve (401), and a third quantitative cup (403) is connected between the No. 10 interface and the No. 7 interface of the fourth switching valve (401).

4. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: The first pre-separation column (105) is a CST column with a length of 0.8 m, an inner diameter of 1 / 8", and a 60-100 mesh packing. The second pre-separation column (205) is a Hayesep R column with a length of 2 m, an inner diameter of 1 / 8", and a 60-80 mesh packing. The third pre-separation column (503) is a DB-1 capillary column with a length of 30 m*0.53 mm and a 60-100 mesh packing. The first analytical column (302) is a 13X column with a length of 2 m, an inner diameter of 1 / 8", and a 60-80 mesh packing. The second analytical column (303) is a Hayesep R column with a length of 6 m, an inner diameter of 1 / 8", and a 60-80 mesh packing. R filling column; the third analytical column (603) is a DB-1 capillary column with a length of 30m*0.53mm and a mesh size of 60-100; the fourth analytical column (602) is a DB-WAX capillary column with a length of 50m*0.53mm and a mesh size of 60-100. All analytical columns and separation columns use stainless steel pipes with passivated inner walls.

5. An analysis device for electronic grade methyl bromide according to claim 4, characterized in that: The inner walls of all stainless steel connecting pipes are passivated with electronic grade methyl bromide for special treatment to prevent adsorption.

6. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: The second interface of the fourth switching valve (401) is connected to a pressure sensor (406), and a sample outlet pipe is provided on the pressure sensor (406). The range of the pressure sensor (406) is -0.1 to 1.1 MPa.

7. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: A sample inlet pipe is provided on the third interface of the first switching valve (101).

8. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: The first detector (304) and the second detector (604) use VICI's helium ionization detector, the detection limit can be increased to 10PPb, and a 6-valve 7-column process is used to achieve full separation of all components in one injection.

9. An analysis device for electronic grade methyl bromide according to claim 1, characterized in that: The fifth switching valve (501) and the sixth switching valve (601) are both connected to a venting pipeline.

10. A method for analyzing electronic grade methyl bromide according to claims 1 to 9, characterized in that: The steps include: S1: Before starting the analysis, each connecting pipeline is purged and replaced by helium purging and vacuuming. After the replacement is completed, the sample to be tested is introduced into the purging injection pipeline. The sample gas to be tested passes through the sample inlet pipe to the first switching valve (101), and passes through the third interface, the second interface, the fifth interface, and the fourth interface of the first switching valve (101) in sequence. The fourth interface of the first switching valve (101) is connected to the third interface of the second switching valve (201) through a stainless steel pipe, and then passes through the second interface, the fifth interface, and the fourth interface of the second switching valve (201) in sequence. The fourth interface is connected to the first interface of the fourth switching valve (401) through a stainless steel pipe, and then passes through the first interface, the tenth interface, the seventh interface, the sixth interface, the third interface, and the second interface of the second switching valve (201) in sequence. Then, the second interface is connected to the pressure sensor (406), so that the sample fills four 0.5mL quantitative loops; S2: During injection, the pressure reading will be transmitted to the chromatographic workstation, and the pressure of the valve at the front end of the injection port will be adjusted to ensure that the injection volume is consistent each time. S3: After the analysis starts, the first switching valve (101), the second switching valve (201) and the fourth switching valve (401) are switched simultaneously, so that the first switching valve (101), the second switching valve (201) and the fourth switching valve (401) are changed from a reset state to a switching state. S4: The carrier gas of the first carrier gas branch pipe (102) sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface, and No. 6 interface of the first switching valve (101) to replace the sample in the first quantitative loop into the first pre-separation column (105) for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane in the sample first flow out of the first pre-separation column (105) to the first analysis column (302). When methane flows into the first analysis column (302), the first switching valve (101) switches to the reset state; the hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane in the sample are separated by the first analysis column (302), and the H2, O2, Ar, N2, CH4 and CO in the sample sequentially flow into the first detector (304) through the No. 3 interface and No. 2 interface of the third switching valve (301); S5: The carrier gas of the third carrier gas branch pipe (202) sequentially passes through the No. 1 interface, No. 2 interface, No. 5 interface and No. 6 interface of the second switching valve (201) to replace the sample in the second quantitative loop into the second pre-separation column (205) for separation. The hydrogen, oxygen, argon, nitrogen, carbon monoxide, methane and carbon dioxide in the sample first flow out of the second pre-separation column (205) to the second analysis column (303). When the carbon dioxide flows into the second analysis column (303), the second switching valve (201) is switched to the reset state, and separated by the second analysis column (303). The hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane in the sample are discharged into the venting pipeline through the No. 1 interface, No. 6 interface, No. 5 interface and No. 4 interface of the third switching valve (301); when the methane is discharged, the third switching valve (301) is switched to the switching state, and the carbon dioxide in the sample flows into the first detector (304) sequentially through the No. 1 interface and No. 2 interface of the third switching valve (301). S6: The carrier gas of the fifth carrier gas branch pipe (402) sequentially passes through the No. 9 interface, No. 10 interface, No. 7 interface, and No. 8 interface of the fourth switching valve (401) to replace the sample in the third quantitative loop into the third pre-separation column (503) for separation. The chloromethane, bromomethane, dichloromethane, bromine, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane, and bromoform in the sample sequentially flow out of the third pre-separation column (503) and flow into the third analytical column (603) for separation. The chloromethane in the sample passes through the No. 4 interface of the pneumatic six-way valve. , and flows into the third analytical column (603) for separation. After methyl bromide flows into the third analytical column (603), the fifth switching valve (501) is switched to the switching state, and the carrier gas of the seventh carrier gas branch pipe (502) flows into the third analytical column (603) through the No. 6 interface and the No. 5 interface of the fifth switching valve (501) in sequence, and then flows into the second detector (604) through the No. 1 interface and the No. 6 interface of the sixth switching valve (601); most of the methyl bromide in the sample is discharged into the venting pipeline through the No. 4 interface and the No. 3 interface of the fifth switching valve (501). After most of the methyl bromide in the sample is vented, the fifth switching valve (501) is switched to a reset state, and dichloromethane, bromine gas, chloroform, bromochloromethane, dibromomethane, bromodichloromethane, 1,2-dibromomethane, and bromoform in the sample flow into the third analytical column (603) through the No. 4 interface and the No. 5 interface of the fifth switching valve (501), and flow into the second detector (604) through the No. 1 interface and the No. 6 interface of the sixth switching valve (601); S7: The carrier gas of the sixth carrier gas branch pipe (405) sequentially passes through the No. 4 interface, No. 3 interface, No. 6 interface, and No. 5 interface of the fourth switching valve (401) to substitute the sample in the fourth quantitative loop into the fourth analytical column (602) for separation. The methyl bromide, hydrogen bromide, and methanol in the sample sequentially flow into the fourth analytical column (602) for separation. After the methyl bromide in the sample flows into the fourth analytical column (602), it is discharged into the venting pipeline through the No. 5 interface, No. 4 interface, No. 2 interface, and No. 3 interface of the sixth switching valve (601). When most of the methyl bromide in the sample is vented, the sixth switching valve (601) is switched to the switching state, and the hydrogen dibromide and methanol in the sample flow into the second detector (604) through the No. 5 interface and No. 6 interface of the sixth switching valve (601); S8: Through the integration processing of the chromatography workstation, one injection can generate a spectrum showing the detection results of two detectors.

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