JP6376357B2 - Pyrolysis sample tube for gas chromatograph and pyrolysis sample introduction device for gas chromatograph - Google Patents

Description

  The present invention relates to a pyrolysis sample tube for gas chromatograph and a pyrolysis sample introduction device for gas chromatograph for introducing a sample into a gas chromatograph.

  As a conventional pyrolysis sample introduction device for introducing a sample into a gas chromatograph, a Curie type pyrolysis sample introduction device and a heating furnace type pyrolysis sample introduction device are known (Patent Document 1). The Curie-point pyrolysis sample introduction device sets a sample wrapped in a ferromagnetic foil (hereinafter referred to as pyrofoil) in a pyrolysis sample tube, induction heats the sample with a high frequency coil, A gas mixed with a carrier gas is introduced into a gas chromatograph. On the other hand, the furnace-type pyrolysis sample introduction device sets a sample wrapped in a package in a pyrolysis sample tube, heats the sample with a heater, and mixes the gas obtained by mixing the pyrolyzed sample with a carrier gas into a gas chromatograph. It is to be introduced.

A conventional pyrolysis sample tube 120 and a Curie point pyrolysis sample introduction device 101 for gas chromatograph equipped with the pyrolysis sample tube 120 will be described with reference to FIG.
A conventional pyrolytic sample introduction apparatus 101 for gas chromatograph is configured by inserting a sample holder 102 into an apparatus main body 110 as shown in FIG. As shown in FIG. 3A, the sample holder 102 includes a pyrolysis sample tube 120 that stores a sample wrapped in a pyrofoil 121, and a sample tube holder 130 that fixes the pyrolysis sample tube 120 to the apparatus main body 110. It has.
The pyrolysis sample introduction device 101 for gas chromatograph includes an apparatus main body 110, a pyrolysis sample tube 120, a sample tube holder 130, a carrier gas supply unit 140 that supplies a carrier gas to the pyrolysis sample tube 120, and a pyrofoil 121. A high frequency coil 150 is provided that generates a high frequency for inductively heating and thermally decomposing the sample. A needle 124 communicating with the tip of the pyrolysis sample tube 120 via the sample introduction tube 122 is disposed at the lower part of the apparatus main body 110. The needle 124 is independently attached to the apparatus main body 110 in advance.
In the pyrolysis sample introduction device 101 for gas chromatograph, the sample pyrolyzed by the high frequency coil 150 flows into the sample introduction tube 122, passes through the inside of the needle 124, and is introduced into the gas chromatograph.

JP 2013-11452 A

  When a polymer such as plastic or rubber is pyrolyzed as a sample, a gaseous compound such as methane or ethane is first generated, and then a general organic compound such as benzene or toluene is generated. Large tar compounds are produced. Since the tar-like compound has a large molecular weight, it is difficult to separate by gas chromatography analysis, and information for knowing the composition of the sample cannot be obtained. Further, since the tar-like compound is not vaporized, it may stay in the sample introduction tube and the needle (transfer line) from the pyrolysis sample tube to the inlet of the gas chromatograph. In that case, since the staying tar-like compound is exposed to high heat for a long time, secondary thermal decomposition occurs, and a gas of a low molecular compound is generated. If the gas overlaps with the gas of the thermally decomposed sample and accumulates, there is a risk that accurate composition information of the sample cannot be obtained. In addition, when the tar-like compound is carbonized and deposited inside the transfer line, the carrier gas may not flow inside the transfer line.

In the conventional pyrolysis apparatus, since the pyrolysis sample tube and the transfer line are provided independently, the pyrolysis sample tube could be replaced, but the transfer line could not be replaced for each analysis. . Therefore, the next analysis must be performed with the tar compound remaining inside the transfer line, and there is a possibility that the qualitative and quantitative determination of the sample cannot be performed with high accuracy.
Further, in the conventional thermal decomposition apparatus, since the transfer line is fixed inside the apparatus main body, it takes time to replace the transfer line.
Further, in the conventional pyrolysis apparatus, it is difficult to provide a heating means around the transfer line due to the structure of the apparatus. Therefore, the temperature of the sample passing through the transfer line is lowered, and there is a possibility that the sample in a stable state suitable for the analysis process cannot be introduced into the gas chromatograph apparatus.

  According to the present invention, the transfer line can be easily exchanged for each analysis, and there is a possibility that the pyrolysis sample tube for gas chromatograph having the transfer line that can prevent the temperature of the sample passing therethrough from staying inside the transfer line. It is an object of the present invention to provide a pyrolysis sample introduction device for gas chromatography capable of performing gas chromatography analysis without being influenced by a certain residue.

  A pyrolysis sample tube for a gas chromatograph according to the present invention includes a sample tube for storing a sample packaging body on which a sample is mounted, a metal connector that is detachably fixed to the sample tube, a through-hole support by the metal connector, And a needle in direct communication with the tube.

  In the pyrolysis sample tube for gas chromatograph according to the present invention, a metal connector constituting the pyrolysis sample tube for gas chromatograph is detachably connected to a first connection member and a first connection member fixed to the sample tube. And a second connecting member, the outer peripheral surface of the sample tube is metallized, and the sample tube and the first connecting member are fixed by metal fusion.

  The pyrolysis sample tube for a gas chromatograph according to the present invention is provided with a first heating part for heating the sample package to thermally decompose the sample, and a predetermined distance in the downstream direction from the tip of the first heating part. It is attached to the inside of the pyrolysis sample introducing device for gas chromatograph provided with the second heating unit, and the needle is arranged in a region between the first heating unit and the second heating unit.

  Furthermore, in the present invention, a pyrolysis sample introduction device for gas chromatograph provided with the above pyrolysis sample tube for gas chromatograph can also be provided.

  The pyrolysis sample tube for a gas chromatograph according to the present invention is a metal tube in which a transfer line, which has conventionally been composed of a sample introduction tube and a needle, is composed of a single needle, and this needle is connected to the sample tube at the time of attachment / detachment. Since it is supported by the connector, it can be replaced with a new needle for each analysis. Therefore, the gas in which the pyrolyzed sample and the carrier gas are mixed can be introduced into the gas chromatograph without being affected by the residue inside the needle, and the qualitative and quantitative determination of the sample can be performed accurately.

  In the pyrolysis sample tube for gas chromatograph according to the present invention, since the outer peripheral surface of the sample tube constituting the pyrolysis sample tube for gas chromatograph is metallized, the sample tube and the first connecting member are fixed by metal fusion. can do. Therefore, the sample tube and the first connection member can be reliably fixed, and the connection portion can be prevented from being damaged. Furthermore, since the second connection member is detachably connected to the first connection member, the needle supported by the second connection member can be easily replaced.

  The pyrolysis sample tube for a gas chromatograph according to the present invention has a first heating unit that generates a high frequency for heating the sample package to thermally decompose the sample, and a predetermined distance downstream from the tip of the first heating unit. Since the needle is disposed in a height region between the second heating unit and the second heating unit, the needle is heated by the heating from the first heating unit. Then, it can introduce into a gas chromatograph, without reducing the temperature of the sample which passes a needle. Therefore, a sample in a stable state suitable for analysis processing can be introduced by a gas chromatograph, and the sample can be analyzed with high accuracy.

  The above-described pyrolysis sample tube for gas chromatography according to the present invention can be applied to a pyrolysis introduction apparatus for gas chromatography.

It is the schematic of the pyrolysis sample tube for gas chromatographs and the pyrolysis sample introduction device for gas chromatography which concerns on embodiment of this invention. (A) Pyrolysis sample tube for gas chromatograph, (b) Pyrolysis sample introduction device for gas chromatograph It is the elements on larger scale of the pyrolysis tube for gas chromatographs concerning the embodiment of the present invention. It is the schematic of the conventional pyrolysis sample tube for gas chromatographs, and the pyrolysis sample introducing device for gas chromatographs. (A) Pyrolysis sample tube for gas chromatograph, (b) Pyrolysis sample introduction device for gas chromatograph.

A pyrolysis sample tube 20 for gas chromatography (hereinafter referred to as a pyrolysis sample tube 20) and a pyrolysis sample introduction device 1 for gas chromatography (hereinafter referred to as a pyrolysis sample introduction device 1) according to the present embodiment will be described. A description will be given with reference to FIG.
The sample holder 2 includes a sample tube holder 30 and a pyrolysis sample tube 20 as shown in FIG. The pyrolysis sample introduction apparatus 1 is configured by attaching a pyrolysis sample tube 20 to a pyrolysis chamber A formed inside the apparatus body 10 as shown in FIG.

[Sample tube holder 30]
The sample tube holder 30 is for fixing the pyrolysis sample tube 20 to the apparatus main body 10. A pyrolysis sample tube 20 is attached to the lower part of the sample tube holder 30. By attaching the sample tube holder 30 to the apparatus main body 10, the pyrolysis chamber A is sealed.
The sample tube holder 30 is formed with a flow path 31 through which carrier gas flows. This flow passage 31 communicates with the pyrolysis sample tube 20.

  The pyrolysis sample tube 20 includes a sample tube 22 that accommodates the sample package 21, a metal connector 23 that is detachably fixed to the sample tube 22, and is supported by the metal connector 23 so as to pass directly therethrough. The needle 24 which communicates is provided.

[Sample tube 22]
The sample tube 22 is made of a material that easily transmits high frequency and has a small dielectric loss. The sample tube 22 may be made of, for example, glass, ceramic, quartz, or alumina having high heat resistance. The sample tube 22 has a cylindrical shape and has an upper region 22A and a lower region 22B communicating with the upper region 22A. A passage is formed in the upper region 22A from the opening at the top of the sample tube 22. This passage has an inner diameter that decreases from the middle of the upper region 22A, passes through the lower region 22B of the sample tube 22, and communicates with the lower opening. Since the inner diameter of the passage is reduced in the middle, a step portion is formed in the upper region 22A.
The sample package 21 is put into the sample tube 22 through the opening at the upper end, and is stored in the sample tube 22 by being left at the stepped portion.
Further, the outer peripheral surface of the distal end portion and the end surface of the distal end portion of the lower region 22B of the sample tube 22 are metallized. The metallization process can be performed, for example, by brazing silver.

[Metal connector 23]
The metal connector 23 includes a first connection member 25 fixed to the sample tube 22 and a second connection member 26 detachably connected to the first connection member 25.
The first connection member 25 includes a sample tube connection member 27 and an intermediate connection member 28 provided at the lower end of the sample tube connection member 27.
As shown in FIG. 2, the sample tube connecting member 27 has a circular fusion groove 27A formed at the upper end, and a through hole is formed in the axial direction from the lower end of the fusion groove 27A. As the sample tube connection member 27, for example, Kovar can be used. The sample tube connecting member 27 is fixed to the sample tube 22 by fitting the distal end portion of the lower region 22B into the fusion groove 27A and performing metal fusion (metal welding).
The intermediate connection member 28 is a member that connects the sample tube connection member 27 and the second connection member 26. For the intermediate connection member 28, for example, stainless steel can be used. The intermediate connection member 28 is connected to the sample tube connection member 27 by welding its upper end surface to the lower end surface of the sample tube connection member 27. A through hole is formed in the intermediate connecting member 28 in the axial direction, and a screw thread is formed on the outer periphery of the intermediate connecting member 28.
The second connection member 26 has a connection hole 26A having a nut groove at the upper end, and a through hole is formed in the axial direction from the lower end of the connection hole 26A. The second connection member 26 is connected to the first connection member 25 via a metal packing 29 described later by screwing the lower end portion of the first connection member 25 into the connection hole 26A. The second connection member 26 is configured to be detachable from the first connection member 25.

[Needle 24]
The needle 24 is made of a material having corrosion resistance against the pyrolyzed sample and the carrier gas, and for example, stainless steel can be used.
The needle 24 is disposed at the lower end of the apparatus main body 10, passes through the first connection member 25 and the second connection member 26, and communicates directly with the sample tube 22. The needle 24 is inserted into the lower region 22B so as to be disposed at the height of the region B described later.
The needle 24 is supported by the inner peripheral surface of the through hole of the second connecting member 26 and the inner peripheral surface of the through hole of the sample tube connecting member 27 and the intermediate connecting member 28 constituting the first connecting member 25. The needle 24 is provided with a metal packing 29.
The gas obtained by mixing the pyrolyzed sample and the carrier gas is introduced into the gas chromatograph through the needle 24.

[Apparatus body 10]
The apparatus main body 10 is made of a member having a heat insulating property, and a pyrolysis chamber A is formed therein.
The pyrolysis chamber A is provided with a high-frequency coil 50 and a heater 60 as a first heating unit that surrounds the outer periphery of the sample tube 22. Further, the heater 60 is provided inside the high-frequency coil 50 so as to surround the outer periphery of the sample tube 22. The high frequency coil 50 and the heater 60 are installed such that their tips (lower end portions) are substantially the same height as the stepped portion. A needle heater 14 as a second heating unit is disposed at the lower end of the apparatus main body 10 toward the outside of the apparatus main body 10. The needle heater 14 is attached at a predetermined distance in the downstream direction from the tips of the high-frequency coil 50 and the heater 60. Therefore, no heating means is provided in a region (hereinafter referred to as region B) from the lower end of the high-frequency coil 50 and the heater 60 to the upper end of the needle heater 14. This region B is a region where a magnetic force is generated by the high frequency coil 50 and is a region heated by the heater 60.
The predetermined distance refers to the distance heated by the high-frequency coil 50 or the heater 60, and the downstream direction refers to the direction in which the heated sample flows.
A carrier gas supply unit 40 is provided on the side of the apparatus main body 10.
A gas chromatograph is disposed at the lower part of the apparatus main body 10, and a septum 15 is provided between the sample inlet of the gas chromatograph and the needle heater 14.

[Carrier gas supply unit 40]
The carrier gas supply unit 40 supplies a carrier gas such as argon, helium, nitrogen, and hydrogen to the pyrolysis sample tube 20. The carrier gas supply unit 40 includes a supply tank 41 and a carrier gas channel 42 that communicates with the supply tank 41 and the channel 31. The carrier gas supplied from the supply tank 41 is supplied to the pyrolysis sample tube 20 via the carrier gas channel 42 and the channel 31.
The carrier gas flow path 42 includes a pressure adjustment valve (not shown), a pressure gauge (not shown) for measuring and displaying the pressure of the carrier gas filled in the supply tank 41, and a switching valve (not shown). The flow rate of the carrier gas can be adjusted by appropriately operating the pressure adjusting valve and the switching valve.

[High-frequency coil 50]
The high-frequency coil 50 induction-heats a sample when the pyrolysis sample introduction device 1 is used as a Curie point type. When the pyrolysis sample introduction device 1 is used as a Curie point type, the sample to be heated is wrapped (attached) in a pyrofoil (sample packaging body 21) made of a ferromagnetic material and stored in the sample tube 22. The high frequency coil 50 is formed by winding a winding around a cylindrical bobbin made of ceramic, and is connected to a high frequency power source (not shown). The lower end of the high frequency coil 50 is supported by the lower end member of the apparatus main body 10. The high frequency coil 50 is induction-heated by operating a high frequency power source.
The high frequency coil 50 can heat a sample in the temperature range of 160 ° C. to 1040 ° C. by selecting pyrofoil.
For the bobbin, alumina, machinable ceramic or zirconia can be used.

[Heater 60]
The heater 60 heats the sample when the pyrolysis sample introduction device 1 is used as a heating furnace type. The heater 60 has a cylindrical shape and heats the sample to cause thermal decomposition. The heater 60 is connected to a heater power source (not shown), and is heated by operating the power source. The heater 60 can be an alumina heater or a ceramic heater, for example. The heater 60 can heat the sample in the range of 40 ° C. to 800 ° C., for example.

Next, the pyrolysis sample introduction device 1 will be described. The pyrolysis apparatus 1 according to the present embodiment can arbitrarily select a Curie point type or a heating furnace type. First, the case where the pyrolysis sample introduction device 1 is used as a Curie point type will be described.
First, a pyrofoil (sample packaging body 21) loaded with a sample is accommodated in the sample tube 22, and the pyrolysis sample tube 20 is fixed to the sample tube holder 30. The pyrolysis sample tube 20 is inserted from the upper part of the apparatus main body 10, and the sample tube holder 30 is fixed to the apparatus main body 10. At this time, the sample tube 22 is attached inside the pyrolysis chamber A, and the needle 24 penetrates the septum 15 and is surrounded by the needle heater 14. A gas chromatograph (not shown) is in a state where a pyrolyzed sample can be introduced, and a needle 24 is inserted into a connecting portion of the gas chromatograph to connect the pyrolyzed sample introducing device 1 and the gas chromatograph.
After filling the supply tank 41 with a predetermined amount of carrier gas, the flow path switching valve is switched so that the supply tank 41 and the pyrolysis sample tube 20 are connected, and the inside of the pyrolysis sample tube 20 is filled with the carrier gas. . And a high frequency power supply is operated and induction heating with the high frequency coil 50 is carried out.

When the high-frequency coil 50 generates a high frequency by supplying power from the high-frequency power source, this high frequency is transmitted through the bobbin to inductively heat the pyrofoil inside the sample tube 22. By this heating, the pyrofoil becomes high temperature and the sample is thermally decomposed. Further, when the sample starts to thermally decompose, the needle heater 14 is heated so that the needle 24 becomes high temperature.
The pyrolyzed sample is mixed with the carrier gas, flows into the passage formed in the lower region 22B of the sample tube 22, and moves to the needle 24. The gas in which the sample and the carrier gas are mixed is introduced into the gas chromatograph via the needle 24 and analyzed.

After completing the analysis, the sample tube holder 30 is pulled upward, and the pyrolysis sample tube 20 is removed from the apparatus main body 10. Since the sample tube holder 30 is fixed to the pyrolysis sample tube 20, when the sample tube holder 30 is removed, the metal connector 23 to which the sample tube 22 and the needle 24 are fixed is shown in FIG. Are simultaneously removed from the apparatus main body 10.
Then, the 2nd connection member 26 is removed and the connection state with the 1st connection member 25 is cancelled | released. At this time, the needle 24 penetratingly supported by the second connecting member 26 is also removed from the sample tube 22 at the same time.
The used needle 24 is removed from the second connecting member 26 and replaced with a new needle 24. Then, the second connection member 26 is connected to the first connection member 25 again, and analysis of a new sample is started.

Next, the case where the pyrolysis sample introduction apparatus 1 is used as a heating furnace type will be described. The method of heating the sample is different from the Curie point type. Other configurations are the same as the Curie point type described above.
First, the sample package 21 fitted with the sample is accommodated in the sample tube 22, and the pyrolysis sample tube 20 is fixed to the sample tube holder 30. The pyrolysis sample tube 20 is inserted from the upper part of the apparatus main body 10, and the sample tube holder 30 is fixed to the apparatus main body 10. At this time, the needle 24 is inserted into the connecting portion of the gas chromatograph, and the pyrolysis sample introduction device 1 and the gas chromatograph are connected.
After the inside of the pyrolysis sample tube 20 is filled with the carrier gas, the heater power supply is operated to heat the sample.

By heating with the heater 60, the sample is thermally decomposed. When the sample starts to thermally decompose, the needle heater 14 is heated so that the needle 24 becomes high temperature.
The pyrolyzed sample is mixed with the carrier gas, flows into the passage formed in the lower region 22B of the sample tube 22, and moves to the needle 24. The gas in which the sample and the carrier gas are mixed is introduced into the gas chromatograph via the needle 24 and analyzed.

In the pyrolysis sample tube 20 of the present embodiment, the first connection member 25 fused and fixed to the sample tube 22 and the second connection member 26 supporting the needle 24 can be easily attached and detached. The needle 24 can be easily detached from the sample tube 22.
Therefore, according to the pyrolysis sample tube 20 of the present embodiment, a new needle 24 can be used for each analysis. Then, even if the tar-like compound generated from the pyrolysis sample stays in the needle 24, the next analysis can be performed using the new needle 24 in which the tar-like compound does not stay. Analysis is possible without being affected by low molecular weight compounds generated by secondary pyrolysis. Therefore, qualitative and quantitative determination of the sample can be performed accurately.
In addition, since the pyrolysis sample tube 20 of this embodiment can use a new needle 24 for each analysis, the tar-like compound prevents the gas mixed with the carrier gas and the pyrolyzed sample from flowing through the needle 24. In addition, gas clogging can be prevented. Then, since a sufficient amount of the mixture can be analyzed with a gas chromatograph, highly accurate information can be obtained.

  In the pyrolysis sample tube 20 according to the present embodiment, the needle 24 is inserted into the sample tube 22 so as to be disposed at the height of the region B. Since the region B is a range heated by the high frequency coil 50 or the heater 60, the needle 24 is heated by the high frequency coil 50 or the heater 60, and can maintain an appropriate temperature. Therefore, it can prevent that the temperature of the sample which passes the needle 24 and is introduce | transduced into a gas chromatograph falls. Therefore, a sample in a stable state suitable for analysis processing can be introduced into the gas chromatograph, and the sample can be analyzed with high accuracy.

  When the sample tube 22 constituting the pyrolysis sample tube 20 according to this embodiment is removed from the apparatus main body 10, the needle 24 can also be removed from the apparatus main body 10. Therefore, when measuring a liquid sample, the pyrolysis sample introduction apparatus 1 can be slid and a liquid sample can be introduce | transduced into a gas chromatograph with a micro syringe.

  As described above, since the sample tube 22 according to the present embodiment is metallized, the outer peripheral surface and the front end surface of the sample tube 22 and the metal first connecting member 25 are metal-welded (metal welding). be able to. Therefore, the sample tube 22 and the first connection member 25 can be securely fixed, and the connected portion is not easily damaged, and both can be fused at low cost.

Although the present embodiment has been described above, the configuration described in the above embodiment can be selected or changed to other configurations as appropriate without departing from the gist of the present invention. .
For example, in the present embodiment, the pyrolysis sample tube 20 using the metal connector 23 having the first connection member 25 and the second connection member 26 has been described. However, a metal connector made of one member may be used. it can.

1 Pyrolysis sample introduction device for chromatograph (Pyrolysis sample introduction device)
2 Sample holder 10 Main body 14 Needle heater (second heating unit)
15 Septum 20 Pyrolysis sample tube for chromatography (pyrolysis sample tube)
21 Sample packaging body 22 Sample tube 22A Upper region 22B Lower region 23 Metal connector 24 Needle 25 First connection member 26 Second connection member 26A Connection hole 27 Sample tube connection member 27A Fusing groove 28 Intermediate connection member 29 Metal packing 30 Sample Tube holder 31 Channel 40 Carrier gas supply unit 41 Supply tank 42 Carrier gas channel 50 High-frequency coil (first heating unit)
60 heater (first heating part)
101 pyrolysis sample introduction device for gas chromatograph 102 sample holder 110 device main body 120 pyrolysis sample tube 124 needle 130 sample tube holder 140 carrier gas supply unit 150 high-frequency coil A pyrolysis chamber B region

Claims (4)

A sample tube for storing a sample package with a sample attached thereto;
A metal connector removably fixed to the sample tube;
A needle that is penetrated and supported by the metal connector and communicates directly with the sample tube;
A pyrolysis sample tube for gas chromatography. The metal connector has a first connection member fixed to the sample tube, and a second connection member detachably connected to the first connection member,
The outer peripheral surface of the sample tube is metallized,
The sample tube and the first connection member are fixed by metal fusion,
The pyrolysis sample tube for gas chromatograph according to claim 1. A gas chromar comprising: a first heating unit that heats the sample package to thermally decompose the sample; and a second heating unit that is provided at a predetermined distance downstream from the tip of the first heating unit. It is installed inside the pyrolysis sample introduction device for togograph,
The needle is disposed in a region between the first heating unit and the second heating unit;
The pyrolysis sample tube for a gas chromatograph according to claim 1 or 2, characterized by the above. The pyrolysis sample tube for a gas chromatograph according to any one of claims 1 to 3, is attached inside,
An apparatus for introducing a pyrolysis sample for a gas chromatograph.

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