JP2022007928A - Device and method for analyzing gas phase component - Google Patents

Abstract

To provide a device and a method for analyzing a gas-phase component that can prevent degradation of a device due to unnecessary components and can obtain an excellent detection sensitivity.SOLUTION: A gas phase component analyzer 1 includes: heating means 2 for heating a sample and generating a gas-phase component mixture; a first column 31 in which the gas-phase component mixture is introduced; a second column 32 as a separation column connected to the first column 31 by connection means 33; a constant-temperature tank 3 for containing the first column 31, the second column 32, and the connection means 33; detection means 4 for detecting a gas-phase component which has passed through the second column 32; and suction means 5 connected to the connection means 33.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas phase component analyzer and a gas phase component analysis method.

Conventionally, gas chromatography is known as a method for analyzing gas phase components. As the gas phase component analyzer (gas chromatograph) used for the gas chromatography, for example, a heating means for heating a sample to generate a gas phase component mixture and the gas generated by the heating means connected to the heating means. It includes a separation column that separates the phase component mixture into individual components, a constant temperature bath (orange) that houses the separation column, and a detector that is connected to the separation column and detects the components separated by the separation column. Things are known.

In the heating means, the vapor phase component mixture is produced by thermally decomposing or volatilizing the sample, or heating the sample to thermally desorb the components contained in the sample. As the detector, a mass spectrometric detector (MS), a hydrogen flame ionization detector (FID), an electron capture detector (ECD) and the like are used.

In the gas phase component analyzer, when analyzing a dilute sample having a sample concentration of less than 0.01% by mass, 90% by mass or more of the gas phase component mixture produced as described above is introduced into the separation column. And analyze. However, in this way, the separation column may be deteriorated by an unreacted methylating agent such as TMAH (tetrammethylniumhydoxide) used when the gas phase component mixture contains a carboxylic acid, or silylation such as HMDS (hemexyldisilazane) may occur. There is a problem that the sensitivity of the hydrogen flame ionization detector (FID) used in the detector changes depending on the agent. Further, in the gas phase component analyzer, when the gas phase component mixture is injected into the separation column 10 to 50 times as much as usual for the purpose of high sensitivity detection, a mass spectrometric detector (MS) is used as the detector. However, there is a problem that a large amount of solvent flows into the mass spectrometer (MS), which makes it impossible to maintain a high vacuum and causes malfunction.

In order to solve the above-mentioned problems, the heating means is provided with a split vent, and a part of the gas phase component mixture is selectively introduced into the separation column, while the rest is discharged to the outside. A gas phase component analyzer is known (see, for example, Patent Document 1).

The gas phase component analyzer described in Patent Document 1 externally removes 90 to 99% of the gas phase component mixture produced as described above from the split vent when analyzing a sample having a sample concentration of 0.01% by mass or more. 1 to 10% of the gas phase component mixture is introduced into the separation column for analysis. As a result, according to the gas phase component analyzer described in Patent Document 1, unnecessary components such as the methylating agent, the silylating agent, and the solvent can be discharged to the outside, and only the analysis target component can be introduced into the separation column. can.

Japanese Unexamined Patent Publication No. 2018-66618

However, the gas phase component analyzer described in Patent Document 1 has a disadvantage that the detection sensitivity is lowered when the amount of the gas phase component mixture introduced into the separation column is small.

INDUSTRIAL APPLICABILITY The present invention eliminates such inconvenience, prevents deterioration of the separation column and detector due to unnecessary non-analytical target components, and can obtain excellent detection sensitivity. It is an object of the present invention to provide a component analysis method.

In order to achieve such an object, in the gas phase component analyzer of the present invention, a heating means for heating a sample to produce a gas phase component mixture and a gas phase component mixture produced by the heating means are introduced. A constant temperature bath containing 1 column, a second column which is a separation column connected to the first column via a connecting means, the first column, the second column, and the connecting means. In the gas phase component analyzer including the detection means for detecting the gas phase component that has passed through the second column, the suction means connected to the connecting means is provided.

Further, the gas phase component analysis method of the present invention is a gas phase component analysis method using the gas phase component analyzer, and when the sample is heated by the heating means to generate the gas phase component mixture, the gas phase component mixture is produced. After the suction means is operated, the sample is charged or injected into the heating means, the suction means is operated for a predetermined time from the time when the sample is charged or injected, and the non-analyzed component is subjected to the suction means. A step of selectively capturing the analysis target component in the first column by setting the temperature of the first column to be higher than the boiling point of the non-analysis target component and lower than the boiling point of the analysis target component while discharging to the outside. After a predetermined time, the suction means is stopped, the temperature of the constant temperature bath is raised to a temperature equal to or higher than the boiling point of the analysis target component, and the analysis target component is introduced into the second column. It is a feature.

In the gas phase component analyzer and the gas phase component analysis method of the present invention, first, the sample is heated by the heating means to thermally decompose or volatilize the sample, or the gas phase component is thermally desorbed from the sample. , The gas phase component mixture is produced. At this time, when the sample is charged or injected into the heating means after the suction means is operated and the suction means is further operated for a predetermined time from the time when the sample is charged or injected, the gas phase component mixture is sucked. Then, the entire amount of the gas phase component mixture is introduced into the first column. The gas phase component mixture contains a high boiling point and low volatile analysis target component and a low boiling point and high volatile non-analysis target component such as a solvent, whereas the first column is the boiling point of the non-analysis target component. Since the temperature is higher and lower than the boiling point of the analysis target component, the non-analysis target component is further sucked in the direction of the suction means without being captured by the first column, while the analysis target component is selected. Is captured in the first column.

Here, the first column is connected to the second column via the connecting means, and the suction means is also connected to the connecting means. However, since the second column acts as a flow path resistance, the non-analyzed component is sucked by the suction means without being introduced into the second column and released to the outside through the suction means. Will be done.

When the non-analyzed component is released to the outside, the suction means is then stopped after the predetermined time, and the temperature of the constant temperature bath is raised to a temperature equal to or higher than the boiling point of the analysis target component. In this way, the analysis target component captured in the first column is vaporized and moves in the direction of the connecting means. At this time, since the suction means is stopped and the direction of the connecting means connected to the suction means is closed, the vaporized component to be analyzed is introduced into the second column. .. Since the second column is a separation column, the analysis target component introduced into the second column is separated into individual gas phase components, and the individual gas phase components that have passed through the second column are said. It is detected by the detection means.

As described above, in the gas phase component analyzer and the gas phase component analysis method of the present invention, the entire amount of the gas phase component mixture produced by the heating means is introduced into the first column, but the solvent and the like are not used. While the analysis target component is released to the outside, the analysis target component is captured in the first column, concentrated, and then introduced into the second column. Therefore, according to the gas phase component analyzer and the gas phase component analysis method of the present invention, deterioration of the separation column and the detector due to unnecessary non-analyzable components such as a solvent can be prevented, and excellent detection sensitivity can be obtained. Obtainable.

The gas phase component analyzer of the present invention selectively introduces a part of the gas phase component mixture produced by the heating means into the first separation column, while discharging the rest to the outside (selective introduction means (). It may be equipped with a backflush device, etc.).

Further, in the gas phase component analysis method of the present invention, the predetermined time as the time for further operating the suction means from the time when the sample is charged or injected into the heating means is 1 second from the time when the sample is charged or injected. The time is preferably in the range of about 3 minutes, and the non-analyzed component can be reliably released to the outside. When the predetermined time is less than 1 second from the time when the sample is charged or injected, the non-analyzed component cannot be sufficiently released to the outside, and even if it exceeds 3 minutes from the time when the sample is charged or injected. No further effect can be obtained.

Further, in the gas phase component analysis method of the present invention, when the temperature of the first column is higher than the boiling point of the non-analyzed component and lower than the boiling point of the analysis target component, the first column is cooled by a refrigerant. The temperature of the first column can be surely set to a temperature lower than the boiling point of the component to be analyzed.

Explanatory sectional view which shows one structural example of the gas phase component analyzer of this invention. Explanatory sectional view which shows the other structural example of the gas phase component analyzer of this invention. The figure which shows one analysis example by the gas phase component analysis apparatus and the gas phase component analysis method of this invention. The figure which shows the other analysis example by the gas phase component analysis apparatus and the gas phase component analysis method of this invention. The figure which shows the further analysis example by the gas phase component analysis apparatus and the gas phase component analysis method of this invention.

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

As shown in FIG. 1, the gas phase component analyzer 1 of the present embodiment is a gas chromatograph, and is a heating device 2, a constant temperature bath 3 connected to the heating device 2, and a detection device connected to the constant temperature bath 3. It is equipped with 4.

The heating device 2 includes a pyrolysis furnace 21 made of a chemically inert hollow cylindrical quartz tube, a heater 22 provided around the pyrolysis furnace 21, and a GC into which the tip of the pyrolysis furnace 21 is inserted. It is provided with an injection port 23. The heater 22 heats the pyrolysis furnace 21 under predetermined conditions by a temperature control device (not shown). The pyrolysis furnace 21 is connected to the upper part of the GC injection port 23 by a heated pipe or the like, or is detachably attached. Further, the pyrolysis furnace 21 may be made of a tube in which a quartz thin film is formed on the inner surface of the stainless tube to make it inert, instead of the quartz tube.

Further, the GC injection port 23 is provided with a heater (not shown), and the heater is adapted to heat the GC injection port 23 under predetermined conditions by a temperature control device (not shown) like the heater 22. If the pyrolysis furnace 21 is not connected or mounted on the upper end of the GC inlet 23, a septum (not shown) is mounted on the upper end.

The heating device 2 includes a sample introduction unit 24 connected above the pyrolysis furnace 21, and a carrier gas conduit 25 as a carrier gas introduction means for introducing carrier gas into the pyrolysis furnace 21 is connected to the sample introduction unit 24. Has been done. The other end of the carrier gas conduit 25 is connected to the carrier gas source 27 via the flow rate control device 26. Further, the carrier gas conduit 25 is connected to the GC inlet 23 when the pyrolysis furnace 21 is not connected or mounted on the upper part of the GC inlet 23.

As a result, the carrier gas supplied from the carrier gas source 27 is adjusted to a predetermined flow rate by the flow rate control device 26 and introduced into the pyrolysis furnace 21 or the GC inlet 23.

In the constant temperature bath 3, the pre-column 31 as the first column, the main separation column 32 as the second column which is the separation column, and the three-way tube as a connecting means for connecting the pre-column 31 and the main separation column 32. (T-shaped tube) 33 is housed. One end of the pre-column 31 is inserted into the GC injection port 23 and faces the tip of the pyrolysis furnace 21, while the other end is connected to the main separation column 32 via a three-way pipe 33. One end of the main separation column 32 is connected to the pre-column 31 via a three-way tube 33, while the other end is connected to a detection means 41 such as a quadrupole mass spectrometric detector housed in the detection device 4. ing.

The three-way pipe 33 linearly connects the pre-column 31 and the main separation column 32, while being connected to the exhaust conduit 34 in a direction orthogonal to the connection direction between the pre-column 31 and the main separation column 32. Is connected to a suction pump 5 such as a vacuum pump provided outside the constant temperature bath 3.

The precolumn 31 is, for example, a fixed layer having an inner diameter of 0.25 mm, a length of 1 m, and a thickness of 0.25 μm composed of a 5:95 (molar ratio) copolymer of methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface. A stainless steel capillary column having an inner diameter of about 0.1 to 0.5 mm, a length of 0.5 to 19 m, and a capillary column coated with various polymers on the inner surface, or chemically inactivating the inner surface without applying the polymer. A polymerized tube can be used. The main separation column 32 has, for example, an inner diameter of 0.25 mm, a length of 30 m, and a thickness of 0. A stainless polymer column with a fixed layer of 25 μm can be used.

The pre-column 31 is removable from the GC injection port 23 and the three-way tube 33, and the pre-column 31 can be selected according to the analysis target.

As the detection means 41, a mass spectrometric detector (MS) such as the quadrupole mass spectrometric detector, a hydrogen flame ionization detector (FID), an electron capture detector (ECD), or the like can be used.

Next, the gas phase component analysis method of the present embodiment using the gas phase component analyzer 1 shown in FIG. 1 will be described.

In the gas phase component analysis method of the present embodiment, first, carrier gas such as helium and nitrogen is supplied from the carrier gas source 27 to the pyrolysis furnace 21 at a flow rate of 5 to 150 ml / min via the flow control device 26. The pyrolysis furnace 21 is heated to a predetermined temperature by the heater 22. Next, after the suction pump 5 is operated, the solid sample or the liquid sample contained in the sample cup 6 is put into the heating furnace 21, and the solid sample is thermally decomposed, the liquid sample is volatilized, or the solid is volatilized. By thermally desorbing the gas phase component from the sample, a gas phase component mixture is generated.

When the thermal decomposition furnace 21 is not connected or mounted on the upper part of the GC injection port 23, the liquid sample or gas sample is injected from the septum into the GC injection port 23 by a microsyring not shown (not shown) and heated. A liquid sample or the gas sample can be volatilized to produce a gas phase component mixture.

Next, the suction pump 5 is further operated for a predetermined time from the time when the sample is charged or injected, for example, for a time in the range of 1 second to 3 minutes, and the entire amount of the gas phase component mixture is introduced into the pre-column 31. At this time, the pre-column 31 is controlled to a predetermined temperature by the constant temperature bath 3 or cooled by a refrigerant such as liquid nitrogen, liquid carbon dioxide, or ice, and is higher than the boiling point of the non-analyzable component contained in the gas phase component mixture. The temperature is lower than the boiling point of the component to be analyzed. As a result, the highly volatile non-analyzable component such as a solvent is not captured by the pre-column 31 but is further sucked in the direction of the suction pump 5, while the analysis target component is selectively captured by the pre-column 31 and concentrated. Will be done.

Here, the pre-column 31 is connected to the main separation column 32 via the three-way pipe (T-shaped pipe) 33, and the suction pump 5 is also connected to the three-way pipe 33 via the exhaust conduit 34. Since the separation column 32 acts as a flow path resistance, the non-analyzed component is sucked into the suction means pump 5 through the exhaust conduit 34 and discharged to the outside without being substantially introduced into the main separation column 32. To. When the main separation column 32 is connected to the mass spectrometric detector (MS), the inside of the mass spectrometric detector is in a vacuum, so that the non-analyzed component is slightly introduced into the main separation column 32. However, since the amount of the non-analyzed component introduced is very small, it does not cause deterioration of the main separation column 32 or malfunction of the mass spectrometric detector.

Next, when the suction pump 5 is stopped after the predetermined time and the temperature of the constant temperature bath 3 is raised to a temperature equal to or higher than the boiling point of the analysis target component, the analysis target component captured in the precolumn 31 is vaporized. It moves in the direction of the directional pipe 33. At this time, in the exhaust conduit 34, the suction pump 5 acts as a valve, and the suction pump 5 is stopped and the valve is closed. Therefore, the vaporized component to be analyzed controls the flow rate of the carrier gas. It is introduced into the main separation column 32, separated into individual gas phase components, and detected by the detecting means 41.

As described above, according to the gas phase component analysis method of the present embodiment using the gas phase component analyzer 1, the non-analyzable component such as a solvent is released to the outside, while the analysis target component is captured by the pre-column 31. Since it is introduced into the main separation column 32 after being concentrated, deterioration of the main separation column 32 and the detection means 41 due to the non-analytical target component can be prevented, and excellent detection sensitivity can be obtained.

As shown in FIG. 2, the gas phase component analyzer 1 may include a split vent 35 as a selective introduction means for selectively introducing the gas phase component mixture into the precolumn 31 at the GC inlet 23. .. The split vent 35 introduces a part of the gas phase component mixture introduced from the pyrolysis furnace 21 or generated at the GC inlet 23 into the precolumn 31, while discharging the rest to the outside from the exhaust pipe 36.

According to the gas phase component analyzer 1 shown in FIG. 2, by providing the split vent 35, when a sample having a sample concentration of 0.01% by mass or more is analyzed, it is introduced from the thermal decomposition furnace 21 or GC Note. 90 to 99% of the gas phase component mixture generated at the inlet 23 can be released to the outside, and 1 to 10% of the gas phase component mixture can be introduced from the pre-column 31 into the main separation column 32 for analysis. Further, when the gas phase component analyzer 1 provided with the split vent 35 is used in the gas phase component analysis method of the present embodiment, first, the split vent 35 is closed for 5 seconds to 5 minutes, the suction pump 5 is operated, and then the suction pump 5 is operated. The sample is charged into the heating furnace 21 or the GC inlet 23 while supplying the carrier gas such as helium and nitrogen from the carrier gas source 27 to the pyrolysis furnace 21 at a flow rate of 5 to 150 ml / min via the flow control device 26. Alternatively, it is injected and pyrolyzed, volatilized or thermally desorbed to produce a gas phase component mixture. By operating the suction pump 5, the split vent 35 does not substantially act, and after the suction pump 5 is stopped, the split vent 35 operates normally, and the carrier gas whose flow rate is controlled as described above is released. Since it is introduced into the pre-column 31, it can operate in the same manner as the gas phase component analyzer 1 shown in FIG.

Next, an example will be shown.

[Example 1]
In this example, first, a hexane solution containing a hydrocarbon having 9 to 22 carbon atoms and an ester thereof at a concentration of 500 ppm was prepared and used as a sample.

Next, using the gas phase component analyzer 1 shown in FIG. 2, 1 μL of the sample was injected into the GC inlet 23 with a microsyringe, and the sample was volatilized to generate a gas phase component mixture.

In this embodiment, in the gas phase component analyzer 1, the pre-column 31 is a copolymer having an inner diameter of 0.25 mm, a length of 1 m, and a methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface in a ratio of 5:95 (molar ratio). A stainless steel capillary column having a fixed layer having a thickness of 0.25 μm was used, and as the main separation column 32, an inner diameter of 0.25 mm, a length of 30 m, and 5:95 (5:95) of methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface. A stainless steel capillary column (manufactured by Frontier Lab Co., Ltd., trade name: UA5-30M-0.25F) having a fixed layer having a thickness of 0.25 μm made of a copolymer of (molar ratio) was used. Further, as the detection means 41, a quadrupole mass spectrometric detector (scan range: m / z 10 to 400) was used.

In the analysis, a carrier gas having a flow rate of 1.0 mL / min was supplied from the carrier gas source 26 to the GC inlet 23 via the flow control device 25, and the split ratio of the split vent 35 was 1/10 (gas phase component to be introduced). 1/10 of the above is introduced into the pre-column 31), the temperature of the GC injection port 23 is 350 ° C., and the temperature of the constant temperature bath 3 is maintained at 40 ° C. for 2 minutes, and then heated to 300 ° C. at a heating rate of 20 ° C./min. I went under the conditions. The analysis result when the suction pump 5 is not operated at all is shown in the upper part of FIG. 3, when the suction pump 5 is operated before the sample injection, the suction pump 5 is operated for 10 seconds after the sample injection, and then stopped. The analysis results are shown in the lower part of FIG.

From FIG. 3, when the suction pump 5 is not operated at all, a peak of the solvent appears in the holding time range of 1 to 5 minutes, and the absolute intensity becomes 1 × ¹⁰⁷ , whereas suction is performed before sample injection. When the pump 5 is operated, the suction pump 5 is operated for 10 seconds after the sample is injected, and then stopped, no peak of the solvent is observed, and the absolute strength is 1 × ¹⁰⁸ , which is 10 times higher. In addition, each hydrocarbon is clearly separated, and it is clear that excellent detection sensitivity can be obtained.

[Example 2]
In this example, first, a dichloromethane solution containing polystyrene having an average molecular weight of 300,000 at a concentration of 0.5 μg / μL and methyl stearate as an internal standard at a concentration of 0.05 μg / μL was prepared and used as a sample.

Next, using the gas phase component analyzer 1 shown in FIG. 2, 5 μL of the sample was collected in a sample cup 6, the solvent was volatilized at room temperature (25 ° C.), and then the heating furnace 21 heated to 600 ° C. was used. The sample was charged and pyrolyzed to produce a gas phase component mixture.

In this embodiment, in the gas phase component analyzer 1, the pre-column 31 is a copolymer having an inner diameter of 0.25 mm, a length of 2 m, and a methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface in a ratio of 5:95 (molar ratio). A stainless polymer column (manufactured by Frontier Lab Co., Ltd., trade name: Ultra ALLOY 50) having a fixing layer having a thickness of 1.0 μm was used, and the main separation column 32 had an inner diameter of 0.25 mm, a length of 30 m, and an inner surface. Stainless steel capillary column (manufactured by Frontier Lab Co., Ltd., trade name: Ultra ALLOY +) provided with a fixed layer having a thickness of 0.5 μm composed of a 5:95 (molar ratio) copolymer of methylphenylpolysiloxane and dimethylpolysiloxane. -5) was used. Further, as the detection means 41, a quadrupole mass spectrometric detector (scan range: m / z 29 to 350) was used.

In the analysis, the carrier gas (helium) having a flow rate of 1.0 mL / min was supplied from the carrier gas source 26 to the heating furnace 21 via the flow rate control device 25, the split ratio of the split vent 35 was 1/16, and the GC inlet 23. The temperature was 300 ° C. and the temperature of the constant temperature bath 3 was maintained at 40 ° C. for 2 minutes, then heated to 280 ° C. at a heating rate of 20 ° C./min, and kept at 280 ° C. for 6 minutes. The analysis result when the suction pump 5 is not operated at all is shown in the upper part of FIG. 4, when the suction pump 5 is operated before the sample is charged, the suction pump 5 is operated for 10 seconds after the sample is injected, and then the suction pump 5 is stopped. The analysis results are shown in the lower part of FIG.

When operating the suction pump 5, a part of the pre-column 31 is immersed in liquid nitrogen in advance, then the suction pump 5 is operated and then stopped, the pre-column 31 is pulled up from the liquid nitrogen, and the temperature of the constant temperature bath 3 is reached. Was heated under the above conditions.

From FIG. 4, it is compared with the case where the suction pump 5 is operated before the sample is charged, the suction pump 5 is operated for 10 seconds from the time when the sample is charged, and then the suction pump 5 is stopped, and the suction pump 5 is not operated at all. The absolute intensity has increased 10 times from 1 × 10 ⁶ to 1 × 10 ⁷ , and the peak area has also increased 12.4 times with methyl steerate and 17.6 times with styrene trimmer, which is an excellent detection. It is clear that sensitivity can be obtained.

[Example 3]
In this example, first, a sample containing 300 μg of polyethylene, 2 μg of nylons 6 and 6, and 80 μg of polypropylene was prepared.

Next, using the gas phase component analyzer 1 shown in FIG. 2, the sample is placed in a sample cup 6 and placed in a heating furnace 21 heated to 600 ° C., and the sample is thermally decomposed to obtain a gas phase component. A mixture was produced.

In this embodiment, in the gas phase component analyzer 1, the pre-column 31 is a copolymer having an inner diameter of 0.25 mm, a length of 1 m, and a methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface in a ratio of 5:95 (molar ratio). A first stainless steel capillary column having a fixed layer having a thickness of 0.5 μm, or a 50:50 (molar ratio) of methylphenylpolysiloxane and dimethylpolysiloxane on the inner surface having an inner diameter of 0.25 mm and a length of 2 m. Exactly the same gas phase component analyzer 1 as in Example 2 was used except that a second stainless steel capillary column provided with a 1.0 μm-thick fixed layer made of the above-mentioned copolymer was used.

The analysis was performed under exactly the same conditions as in Example 2, the suction pump 5 was operated before the sample was charged, the suction pump 5 was further operated for 10 seconds from the time of sample charging, and then stopped.

The analysis result when the first stainless steel capillary column is used as the pre-column 31 is shown in the upper part of FIG. 5, and the analysis result when the second stainless steel capillary column is used is shown in the lower part of FIG. The analysis result of this example is a selective ion chromatogram (EIC) when only mass ion m / z 84 is selected in a pyrogram having a retention time in the range of 5.2 to 6.8 minutes.

In the thermal decomposition of the sample, C8'with 8 carbon atoms and one double bond and saturated hydrocarbon C8 with 8 carbon atoms are produced from polyethylene, cyclopentanone is produced from nylons 6 and 6, and polypropylene is produced. Propylene trimer (propylene trimmer) is produced from the product. Here, when the first stainless steel capillary column shown in the upper part of FIG. 5 is used, the peak with a retention time of 5.9 minutes is a mixture of two components, C8'and cyclopentanone. In the polymer qualitative analysis, improvement of separation is required to perform polymer qualitative analysis of polyethylene and nylon 6 and 6 using C8'and cyclopentanone.

Therefore, when the pre-column 31 was examined in various ways and the second stainless steel capillary column having an increased polar group concentration was used, C8'and cyclopentanone could be completely separated as shown in the lower part of FIG. it is obvious.

In the gas phase component analysis method using a separation column, even if a high-resolution main separation column 32 having a length of 30 m or more is used, a plurality of compounds are often detected in an overlapping manner without being separated. In such a case, it is necessary to change the polarity of the liquid phase applied to the main separation column 32 in order to improve the separation of the plurality of components. However, for that purpose, it is required to prepare a new main separation column 32 and perform an analysis study again, which requires a great deal of labor and a corresponding consideration.

On the other hand, in the gas phase component analysis method of this example, the effect of improving the separation can be obtained only by changing the pre-column 31 according to the analysis target. Therefore, a new separation column is prepared as the main separation column 32. The effort required to do this and the associated costs can be significantly reduced.

1 ... Gas phase component analyzer, 2 ... Heating means, 3 ... Constant temperature bath, 4 ... Detection means, 5 ... Suction means 31 ... First column, 32 ... Second column, 33 ... Connection means, 35 ... Selective Introductory means.

Claims (5)

A heating means that heats the sample to produce a gas phase component mixture,
The first column into which the gas phase component mixture produced by the heating means is introduced, and
A second column, which is a separation column connected to the first column via a connecting means,
A constant temperature bath accommodating the first column, the second column, and the connecting means, and the like.
In a gas phase component analyzer provided with a detection means for detecting a gas phase component that has passed through the second column.
A gas phase component analyzer comprising a suction means connected to the connecting means. In the gas phase component analyzer according to claim 1, a part of the gas phase component mixture produced by the heating means is selectively introduced into the first column, while the rest is discharged to the outside. A gas phase component analyzer characterized by being equipped with. It is connected to the first column via a heating means for heating a sample to generate a gas phase component mixture, a first column into which the gas phase component mixture produced by the heating means is introduced, and a connecting means. A second column, which is a separation column, a constant temperature bath accommodating the first column, the second column, and the connecting means, and a detecting means for detecting a gas phase component that has passed through the second column. A gas phase component analysis method using a gas phase component analyzer including a suction means connected to the connection means.
When the sample is heated by the heating means to generate the gas phase component mixture, the sample is charged or injected into the heating means after the suction means is operated, and the sample is charged or injected. Further, the suction means is operated for a predetermined time to release the non-analyzed component to the outside through the suction means, while the temperature of the first column is higher than the boiling point of the non-analyzing target component and lower than the boiling point of the analysis target component. The step of selectively capturing the analysis target component in the first column as the temperature, and
It is characterized by comprising a step of stopping the suction means after the predetermined time, raising the temperature of the constant temperature bath to a temperature equal to or higher than the boiling point of the analysis target component, and introducing the analysis target component into the second column. Gas phase component analysis method. The gas phase component analysis method according to claim 3, wherein the predetermined time is a time in the range of 1 second to 3 minutes from the time of injecting the sample. In the gas phase component analysis method according to claim 3 or 4, the first column is at a temperature higher than the boiling point of the non-analyzed component and lower than the boiling point of the analysis target component. A gas phase component analysis method comprising cooling a column with a refrigerant.

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